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SUPEMLLOYS
2016
SUPEMLLOYS
2016
Proceedings of the

13th International Symposium

on Superalloys

Sponsored by
the Seven Springs International Symposium Committee in cooperation with the
High Temperature Alloys Committee of the Structural Materials Division of TMS
(The Minerals, Metals & Materials Society) and co-sponsored by ASM International
and IOM 3 (The Institute of Materials, Minerals and Mining)

Held
September 11-15, 2016 at the Seven Springs Mountain Resort,
Seven Springs, Pennsylvania, USA

Edited by
Mark Hardy, Eric Huron, Uwe Glatzel, Brian Griffin, Beth Lewis, Cathie Rae,
Venkat Seetharaman, and Sammy Tin

W l LEY TMS
 Copyright © 2016 by The Minerals, Metals & Materials Society.
All rights reserved.

Published by John Wiley & Sons, Inc., Hoboken, New Jersey.

Published simultaneously in Canada.

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10 9 8 7 6 5 4 3 2 1

W l LEY TIMIS
 TABLE OF CONTENTS
Superalloys 2016
Preface xiii
Dedication xv
Best Paper Award xv/'/'
Committee Members x/'x

Symposium Keynote Address

Innovation through Collaboration 3

S.J. Patel and J.J. deBarbadillo

Session 1: Alloy Development I

Alloys-by-Design: Towards Optimization of Compositions of Nickel-Based Superalloys 15

Roger C. Reed, Alessandro Mottura, and David J. Crudden

CMSX-4® Plus Single Crystal Alloy Development, Characterization and Application Development 25
Jacqueline B. Wahl and Ken Harris

Development of a Low-Density Rhenium-Free Single Crystal Nickel-Based Superalloy by Application of Numerical

Multi-Criteria Optimization Using Thermodynamic Calculations 35
RalfRettig, Kami I Matuszewski, Alexander Müller, HaraldE. Helmer, Nils C. Ritter, and Robert F. Singer

Investigation of Superalloy Composition Space Using High Throughput Thin Film Synthesis and Synchrotron X-Ray
Diffraction 45
L.D. Connor, P.M. Mignanelli, S. Guérin, J.P. Soulié, C. Mormiche, S. Frost, R. Greenhalgh, B.E. Hayden,
and H.J. Stone

Interactive Session A: Alloy Development II

Development of a Low-Cost Third Generation Single Crystal Superalloy DD9 57

J.R. Li, S.Z. Liu,X.G. Wang, Z.X. Shi, andJ.Q. Zhao

Grain Boundary Precipitation Strengthening of Phosphorus-Added Nickel-Iron Base Superalloy 65

Yusaku Hasebe, Koichi Takasawa, Takuya Ohkawa, Eiji Maeda, and Takashi Hatano

Development of New SX Superalloys - Fast Experimental Feedback Versus Thermodynamic Modeling 75

R. Võlkl, E. Fleischmann, R. Rettig, E. Affeldt, and U. Glatzel

Experimental Study of the Binary Ni-Ru-System Using Diffusion Couples Manufactured by Encapsulating Cast 83
Robert Popp, Rainer Võlkl, Thomas Gõhler, and Uwe Glatzel

The Role of Local Chemical Composition for TCP Phase Precipitation in Ni-Base and Co-Base Superalloys 89
T. Hammerschmidt, J. Kofimann, C.H. Zenk, S. Neumeier, M. Gõken, I. Lopez-Galilea, L. Mujica Roncery,
S. Huth, A. Kostka, W. Theisen, and R. Drautz

Precipitation Kinetic Modeling of the New Eta-Phase Ni6AlNb in Ni-Base Superalloys 97

Markus Rath, Erwin Povoden-Karadeniz, and Ernst Kozeschnik

Development of Ni-Cr-Fe-W-Al Superalloy for Advanced Ultra-Supercritical Fossil Power Plants 107
X. C. Hao, M. Q. Ou, T. Liang, C. Xiong, Y. C. Ma, and K. Liu

Development of Low or Zero-Rhenium High-Performance Ni-Base Single Crystal Superalloys for Jet Engine and
Power Generation Applications 115
Kyoko Kawagishi, Tadaharu Yokokawa, Toshiharu Kobayashi, Yutaka Koizumi, Masao Sakamoto,
Michinari Yuyama, Hiroshi Harada, Lkuo Okada, Masaki Taneike, and Hidetaka Oguma

ν
Design of Next Generation Ni-Base Single Crystal Superalloys Containing Ir: Towards 1150 °C Temperature
Capability 123
T. Yokokawa, H. Harada, Y. Mori, K. Kawagishi, Y. Koizumi, T. Kobayashi, M. Yuyama, and S. Suzuki

Sulfur and Minor Element Effects on the Oxidation of Bilayer γ'+ β Bond Coats for Thermal Barrier Coatings on
René N5 131
David J. Jorgensen, Akane Suzuki, Don M. Lipkin, and Tresa M. Pollock

High Temperature Creep of γ'-Containing CoNi-Based Superalloys 141

Michael S. Titus, Luke H. Rettberg, and Tresa M. Pollock

Effects of Si Addition on the High Temperature Strength and Oxidation Behavior of γ'-Bearing Co-Based
Superalloys 149
An-Chou Yeh, L-Ting Ho, Sheng-Chi Wang, and Chia-Fu Cheng

The Effect of Alloying Elements on the High Temperature Oxidation of Solid-Solution Strengthened Ni-Base
Superalloys 159
Dae Won Yun, Y.S. Yoo, H.W. Jeong, and SM. Seo

Effect of Bond Coat and Substrate Chemistry on the Interfacial Degradation of Thermal Barrier Coatings 167
L. T. Wu, R. T. Wu, T. Osada, KL. Lee, Μ. Bai, and P. Xiao

Effect of Re and Ta on Hot Corrosion Resistance of Nickel-Base Single Crystal Superalloys 177
J.X. Chang, D. Wang, G. Zhang, L.H. Lou, and J. Zhang

Session 2: Alloy Development III

Advanced Supersolvus Nickel Powder Disk Alloy DOE: Chemistry, Properties, Phase Formations and Thermal
Stability 189
Andrew Powell, Ken Bain, Andrew Wessman, Daniel Wei, Timothy Hanlon, and David Mourer

Y Phase Instabilities in High Refractory Content γ Y Ni-Base Superalloys 199

Stoichko Antonov, Dieter Lsheim, David N. Seidman, Eugene Sun, Randolph C. Helmink, and Sammy Tin

Development of Nickel-Cobalt Base P/M Superalloys for Disk Applications 209

Y.F. Gu, T. Osada, Τ. Yokokawa, Η. Harada, and J. Fujioka

Superalloys for Advanced Energy Applications: Inconel Alloy 740H - A Case Study on International
Government-Industry-University Collaboration 217
John deBarbadillo, Brian Baker, andXishan Xie

Session 3: Blade Alloy Manufacture

Application and Validation of a Directional Solidification Model and Dendrite Morphology Criterion for Complex,
Single-Crystal Castings 229
J.D. Miller, K.J. Chaput, D.S. Lee, andM.D. Uchic

Innovations in Casting Techniques for Single Crystal Turbine Blades of Superalloys 237
Dexin Ma, Fu Wang, Qiang Wu, Samuel Bogner, and Andreas Bührig-polaczek

The Distribution and Retention of Yttrium and Lanthanum in Cast Single Crystal Superalloys 247
S.P. Leyland, LMEdmonds, S. Lrwin, C.N. Jones, A. Bhowmik, D. Ford, and C.M.F. Rae

Interactive Session B: Alloy & Component Manufacture I

Multiscale Modeling of Heat Treatment Processing for Single-Crystal Ni-Base Superalloys 259
Chen Shen, Akane Suzuki, and Douglas G. Konitzer

vi
Microstructure Instability of Ni-Base Single Crystal Superalloys during Solution Heat Treatment 267
N. D 'Souza, D. Welton, J. Kelleher, G.D. West, Z.H Dong, G. Brewster, and H.B. Dong

Development of Thermal Barrier Coating System Using EQ Coating for Advanced Single Crystal Superalloys 279
Kazuhide Matsumoto, Kyoko Kawagishi, and Hiroshi Harada

Effect of Rejuvenation Heat Treatment and Aging on the Microstructural Evolution in Rene N5 Single Crystal Ni
Base Superalloy Blades 285
Joydeep Pala, Dheepa Srinivasana, and Eric Cheng

The Formation Mechanism, Influencing Factors and Processing Control of Stray Grains in Nickel-Based Single
Crystal Superalloys 293
Yafeng Li, Lin Liu, Taiwen Huang, Dejian Sun, Jun Zhang, and Hengzhi Fu

Resonant Ultrasound Spectroscopy for Defect Detection in Single Crystal Superalloy Castings 303
B.R. Goodlet, L.H. Rettberg, and T.M. Pollock

Investigation of Oxide Bifilms in Investment Cast Superalloy IN100 313

M.A. Kaplan, R.K Guarriello, and G.E. Fuchs

A New Analysis of the Microstructure of Ni-Based Single-Crystal Superalloys: Relevant Topological Parameters
for Efficient Microstructural Modeling 323
M. Degeiter, M. Perrut, B. Appolaire, Y. Le Bouar, and A. Fine I

Single-Crystal Superalloy Joining 333

Akane Suzuki, Jeffrey Schoonover, Chen Shen, and David Wark

Selective Electron Beam Melting of the Single Crystalline Nickel-Base Superalloy CMSX-4®: From Columnar
Grains to a Single Crystal 341
Markus Ramsperger and Carolin Kòrner

Defect Formation and Its Mitigation in Selective Laser Melting of High γ' Ni-Base Superalloys 351
Xiqian Wang, Noriko Read, Luke N. Carter, R. Mark Ward,Moataz andM. Attallah

Developing Processing Parameters for Nickel-Base Superalloys for the Electron Beam Melting Additive
Manufacturing Process 359
Francisco Medina, Michael Kirka, UlfAckelid, and Ryan Dehoff

Parameter Optimization for Electron Beam Melting of IN718 Based on Melt Pool Characterization 367
Xiao Ding, Yuichiro Koizumi, andAkihiko Chiba

Effect of Heat Treatments on the Microstructure and Texture of CM247LC Processed by Selective Laser Melting 375
R. Muñoz-Moreno, V.D. Divya, OM.D.M. Messé, Τ. Lllston, S. Baker, and H.J. Stone

Session 4: Blade Alloy Behavior

Thermal Cycling Creep Resistance of Ni-Based Single Crystal Superalloys 385

Jonathan Cormier

Influence of Crystal Orientation on Cyclic Sliding Friction and Fretting Fatigue Behavior of Single Crystal Ni-Base
Superalloys 395
Balavenkatesh Rengara], Sotaro Baba, andMasakazu Okazaki

Sustained Peak Low-Cycle Fatigue in Single Crystals with Equilibrium γ-γ' Coatings 405
M.A. Lafata, L.H. Rettberg, C. Mercer, and T.M. Pollock

vii
 Session 5: Disk Alloy Manufacture

Heteroepitaxial Recrystallization Observed in René 65™ and Udimet 720™: A New Recrystallization Mechanism
Possibly Occurring in All Low Lattice Mismatch γ-γ' Superalloys 417
Marie-Agathe Charpagne, Thomas Billot, Jean-Michel Franchet, and Nathalie Bozzolo

Systematic Evaluation of Microstructural and Thermo-Mechanical Effects on the As-Forged Condition of Alloy
ATI 718Plus® 427
Ana Casanova, Katja Loehnert, Daniela Huenert, Mark Hardy, and Catherine Rae

Effect of Ingot Size on Microstructure and Properties of the New Advanced AD730™ Superalloy 437
C. Croze t, A. Devaux, R. Forestier, S. Charmond, M. Hue Her, D. Helm, and W. Buchmann

Inhomogeneous Grain Coarsening Behavior in Supersolvus Heat Treated Nickel-Based Superalloy RR1000 447
IM.D. Parr, T.J. Jackson, M.C. Hardy, D.J. Child, C. Argyrakis, K. Severs, V. Saraf, andJ.M. Stumpf

Interactive Session C: Alloy & Component Manufacture II

The Influence of the Starting Grain Size during High-Temperature Grain Boundary Engineering of Ni-Base
Superalloy RR1000 459
Martin Detrois, John Rotella, Robert L. Goetz, Randolph C. Helmink, and Sammy Tin

Evaluation of AD730™ for High Temperature Fastener Applications 469

A. Devaux, W. Li, C. Crozet, and J.M. Lardón

Conventionally Forged RR1000 Billet for Forged Turbine Components 479

Kevin J. Bockenstedt, Christopher M. O 'Brien, Ramesh S. Minisandram, George J. Smith, and David J. Bryant

Deformation Mechanisms and Microstructural Evolution of γ + γ' Duplex Aggregates Generated during
Thermo mechanical Processing of Nickel-Base Superalloys 487
Beijiang Zhang, Guangpu Zhao, Wenyun Zhang, Guohua Xu, and Heyong Qin

Full Field Modeling of the Zener Pinning Phenomenon in a Level Set Framework - Discussion of Classical Limiting
Mean Grain Size Equation 497
B. Scholtes, D. Llin, A. Settefrati, N. Bozzolo, A. Agnoli, andM. Bernacki

Friction Stir Processing of Cast Alloy 718 505

Bharat K. Jasthi, Edward Chen, Brahmanandam Kaligotla, Todd Curtis, Michael West, and Christian Widener

Integrated Process Modeling for the Mechanical Properties Optimization of Direct Aged Alloy 718 Engine Disks 513
Bernd Oberwinkler, Andreas Fischersworring-Bunk, Marco Hüller, and Martin Stockinger

Influence of Carbide Distribution on Ductility of Haynes®282® Forgings 523

C. Joseph, M. Hòrnqvist, R. Brommesson, and C. Persson

An Approach to Microstructure Modelling in Nickel Based Superalloys 531

Aleksey Reshetov, Olga Bylya, Nicola Stefani, Malgorzata Rosochowska, and Paul Blackwell

Mechanical Properties of Cast & Wrought Hybrid Disks 539

Hesser Taboada Michel, Layla Sasaki Reda, Georgia Effgen Santos, Jonathan Cormier, Christian Dumont,
Patrick Villechaise, Philippe Bocher, Damien Texier, Eric Georges, Florent Bridier, Florence Hamon,
and Alexandre Devaux

viii
 Session 6: Disk Alloy Behavior I

Separating the Influence of Environment from Stress Relaxation Effects on Dwell Fatigue Crack Growth in a
Nickel-Base Disk Alloy 551
J. Telesman, T.P. Gabb, and L.J. Ghosn

Microstructural Aspects of Fatigue Crack Initiation and Short Crack Growth in René 88DT 561
Zafir Alam, David Eastman, George Weber, Somnath Ghosh, and Kevin Hemker

Statistical Assessment of Fatigue-Initiating Microstructural Features in a Polycrystalline Disk Alloy 569

William C. Lenthe, Jean-Charles Stinville, McLean P. Echlin, and Tresa M. Pollock

Determination of Orientation and Alloying Effects on Creep Response and Deformation Mechanisms in Single
Crystals of Ni-Base Disk Superalloys 579
T.M. Smith, L. V. Duchao, T. Hanlon, A. Wessman, Y. Wang, and M.J. Mills

Session 7: Alloy & Component Manufacture III

High Temperature Properties of a Single Crystal Superalloy PWA1484 Directly Recycled after Turbine Blade Use 591
Satoshi Utada, Yuichiro Joh, Makoto Osawa, Tadaharu Yokokawa, Toshiharu Kobayashi, Kyoko Kawagishi,
Shinsuke Suzuki, and Hiroshi Harada

Manufacture of Large Ni-Base Ingots and Forgings 601

Nikolaus Blaes, Bernhard Donth, Andreas Diwo, and Dieter Bokelmann

Influence of Hot Working Conditions on Grain Growth Behavior of Alloy 718 609
Chuya Aoki, Tomonori Lleno, and Takehiro Ohno

Microstructure-Sensitive Model for Predicting Surface Residual Stress Relaxation and Redistribution in a P/M
Nickel-Base Superalloy 619
M.E. Burba, D.J. Buchanan, M.J. Catón, R. John, andRA. Brockman

Interactive Session D: Alloy & Component Behavior I

Fatigue Crack Growth Rate Assessment of Superalloys by the EBSD Method 631
D. Kobayashi, T. Takeuchi, andM. Achiwa

Stage I Fatigue Crack Propagation in a Single Crystal and a Directional Solidified Ni-Base Superalloy 639
Motoki Sakaguchi, Ryota Komamura, Yuta Hosaka, and Hirotsugu Lnoue

Anisothermal High-Temperature Cyclic Behavior of a Ni-Based Single Crystal Superalloy 647

Jean-Briac le Graverend, Jonathan Cormier, Franck Gallerneau, Serge Kruch, and José Mendez

Discussing the Effect of Gamma Prime Coarsening on High Temperature Low Stress Creep Deformation with
Respect to the Role of Refractory Elements 655
T. Goehler, C. Schwalbe, J. Svoboda, E. Affeldt, andR.F. Singer

On the Development of ICME Tools for Creep and Aging of CMSX®-8 665
E.A. Estrada Rodas, S. Gorgannejad, R. W. Neu, Z. Dyer, P.M. Draa, and S.R. Shinde

Creep Deformation of a 6th Generation Ni-Base Single Crystal Superalloy at 800 °C and 735 MPa 675
Y. Yuan, K. Kawagishi, Y. Koizumi, T. Kobayashi, T. Yokokawa, and H. Harada

Effect of Hf and Β on Transverse and Longitudinal Creep of a Re-Containing Nickel-Base Bicrystal Superalloy 683
Y.S. Zhao, J. Zhang, Y.S. Luo, G. Sha, D. Ζ. Tang, and Q. Feng

ix
Mechanical Properties and Microstructure Design in Repairing Mar-M 509 Alloy Turbine Components 693
Zengmei Wang Koenigsmann, Ravi Shankar, and Richard Fenton

Evaluation of Temperature and Stress in First Stage High Pressure Turbine Blades of a Directionally-Solidified
Superalloy DZ125 after Service in Aeroengines 701
Y.D. Chen, Y.R. Zheng, C.B. Xiao, and Q. Feng

On the Temperature Dependence of Creep Behavior of Ni-Base Single Crystal Superalloys 711
P. Wollgramm, X. Wu, and G. Eggeler

Microstructure Changes and Oxidation Resistance of Aluminized Ni-Based Single Crystal Superalloys 719
Hideyuki Murakami and Kazuki Kasai

Factors Affecting TBC Furnace Cycle Lifetime: Temperature, Environment, Structure and Composition 727
B.A. Pint, J A. Haynes, M.J. Lance, H.L. Aldridge, Jr., V. Viswanathan, G. Dwivedi, and S. Sampath

Oxidation Coating Life Extension in Gas Turbine Blades during Repair 735
Dheepa Srinivasan, N. Dayananda, Neha Kondekar, Mounika Gandi, and Hariharan Sundaram

Session 8: Blade Alloy Behavior II

High Temperature Creep Damage Mechanisms in a Directionally Solidified Alloy: Impact of Crystallography and
Environment 747
L. Mataveli Suave, J. Cormier, P. Villechaise, D. Bertheau, G. Benoit, F. Mauget, G. Cailletaud, and L. Marcin

Characterization of Tilt and Twist Low Angle Grain Boundaries and Their Effects on Intermediate-Temperature
Creep Deformation Behaviour 757
Yao Wang, Dong Wang, Gong Zhang, Langhong Lou, and Jian Zhang

Crack Initiation and Propagation during Thermal-Mechanical Fatigue of IN792: Effects of Dwell Time 763
Paraskevas Kontis, DavidM. Collins, Sten Johansson, Angus J. Wilkinson, Johan J. Moverare,
and Roger C. Reed

Creep and Oxidation Behaviour of Coated and Uncoated Thin Walled Single Crystal Samples of the Alloy
PWA1484 773
Fabian Krieg, Mike Mosbacher, Markus Fried, Ernst Affeldt, and Uwe Glatzel

Session 9: Disk Alloy Behavior II

ATI718Plus® - New Nickel Based Disc Alloy and Its Capability 783
D. Huenert, M. Proebstle, A. Casanova, R. Schluetter, R. Krakow, M. Buescher, P. Randelzhofer, A. Evans,
K. Loehnert, T. Witulski, S. Neumeier, and C. Rae

Thermal Stability of Cast and Wrought Alloy Rene 65 793

Andrew Wessman, Aude Laurence, Jonathan Cormier, Patrick Villechaise, Thomas Billot,
and Jean-Michel Franchet

Novel Techniques to Assess Environmentally-Assisted Cracking in a Nickel-Based Superalloy 801

André A.N. Németh, David J. Crudden, David M. Collins, David E.J. Armstrong, and Roger C. Reed

Interactive Session E: Alloy & Component Behavior II

Benchmarking Crystal Plasticity Models with Micro tensile Evaluation and 3D Characterization of René 88DT 813
David W. Eastman, Zafir Alam, George Weber, Paul A. Shade, Michael D. Uchic, William C. Lenthe,
Tresa M. Pollock, and Kevin J. Hemker

χ
Characterization and Modeling of Deformation Mechanisms in Ni-Base Superalloy 718 821
D. McAllister, D. Lv, H. Deutchman, B. Peterson, Y. Wang, and M.J. Mills

Dislocations Nucleation and Interaction with Grain Boundaries in a Polycrystalline Nickel Base Superalloy 831
O.M.D.M. Messé and C.M.F. Rae

Effect of Large Plastic Strains and Strain Gradients on Residual Stress Relaxation in Shot Peened IN100 841
Dennis J. Buchanan and Reji John

Relationship between the Microstructure, Low Cycle Fatigue and Creep Properties of a Cast and Wrought Ni-Co
Base Superalloy TMW-4M3 Disk 849
Shinichi Kobayashi, Tomonori Lleno, Takehiro Ohno, and Hiroshi Harada

Probability of Occurrence of Life-Limiting Fatigue Mechanism in P/M Nickel-Based Superalloys 859

S.K Jha, W.J. Porter, M.J. Catón, R. John, D.J. Buchanan, A.H. Rosenberger, andJ.M. Larsen

Influence of Residual Stresses on the Fatigue Life of a Shot-Peened Nickel-Based Single Crystal Superalloy: From
Measurements to Modeling 867
Amélie Morançais, Mathieu Fèvre, Manuel François, Nicolas Guel, Serge Kruch, Pascale Kanouté,
and Arnaud Longuet

Relationships between Microstructural Parameters and Time-Dependent Mechanical Properties of a New Nickel
Based Superalloy AD730™ 877
Louis Thébaud, Patrick Villechaise, Jonathan Cormier, Florence Hamon, Coraline Crozet, Alexandre Devaux,
Jean-Michel Franchet, Anne-Laure Rouffié, andAntoine Organista

A Unified LCF Model for Conventionally Heat Treated Inconel 718 887
Michael D. Marotta and David C. Dudzinski

Effect of Non-Metallic Ceramic Inclusions on Strain Localization during Low Cycle Fatigue of a Polycrystalline
Superalloy 897
Jean-Charles Stinville, Victoria M. Miller, and Tresa M. Pollock

Effects of Oxidation on Fatigue Crack Initiation and Propagation in an Advanced Disk Alloy 907
R. Jiang, N. Gao, Μ. Ward, Ζ. Aslam, J.C. Walker, and P.A.S. Reed

Physics-Based Modeling Tools for Predicting Type II Hot Corrosion in Nickel-Based Superalloys 917
KS. Chan, M.P. Enright, J.P. Moody, and S.H.K. Fitch

Characterization of Grain Boundaries and Associated Minor Phases in Disk Alloy ME3 Exposed at 815 °C 927
Chantal K. Sudbrack, Laura J. Evans, Anita Garg, Daniel E. Perea, and Daniel K. Schreiber

Session 10: Environmental Behavior

Slip Localization and Hydrogen Embrittlement of Alloy 718 939

Zhenbo Zhang, Gideon Obasi, Roberto Morana, and Michael Preuss

Effects of Sea Salt on the Oxidation of CMSX-4® at 1100 °C 949

Η. T. Pang, F. Li, S. Pahlavanyali, L.M. Edmonds, G. Brewster, and C.M.F. Rae

Damage Evolution during Compressive Hold Sustained Peak Low Cycle Fatigue of a Ni-Based Single-Crystal
Superalloy 959
Swapnil Patil, Shenyan Huang, Mallikarjun Karadge, Doug Konitzer, and Akane Suzuki

xi
 Session 11: Co 3 AlW & High Entropy Alloys

The Role of the Base Element in γ' Strengthened Cobalt/Nickel-base Superalloys 971
C.H. Zenk, S. Neumeier, M. Kolb, N. Volz, S. G. Fries, O. Dolotko, I. Povstugar, D. Raabe, andM. Gõken

Alloying Effects on Microstructural Stability and γ' Phase Nano-Hardness in Co-Al-W-Ta-Ti-Base Superalloys 981
H.J. Zhou, W.D. Li, F. Xue, L. Zhang, X.H. Qu, and Q. Feng

Oxide Scale Formation in Novel γ-γ' Cobalt-Based Alloys 991

C.A. Stewart, R.K. Rhein, A. Suzuki, T.M. Pollock, and C.G. Levi

High Temperature Properties of Advanced Directionally-Solidified High Entropy Superalloys 1001

Te-Kang Τ sao, An-Chou Y eh, Jien-Wei Y eh, Mau-Sheng Chiou, Chen-Ming Kuo, H. Murakami,
and Koji Kakehi

Session 12: Additive Layer Manufacture

Inconel 625 by Direct Metal Laser Sintering: Effects of the Process Parameters and Heat Treatments on Microstructure
and Hardness 1013
Giulio Márchese, Massimo Lorusso, Flaviana Calignano, Elisa Paola Ambrosio, Diego Manfredi,
Matteo Pavese, Sara Biamino, Daniele Ugues, and Paolo Fino

A Multi-Scale Multi-physics Approach to Modelling of Additive Manufacturing in Nickel-Based Superalloys 1021

C. Panwisawas, Y. Sovani, M.J. Anderson, R. Turner, N.M. Palumbo, B. C. Saunders, L. Choquet, J. W. Brooks,
and H. C. Basoalto

Integrated Thermal Process Optimization of Alloy 718Plus® for Additive Manufacturing 1031
Jiadong Gong, Hallee Z. Deutchman, Alonso Peralta, Dave Snyder, Michael P. Enright, John McFarland,
James Neumann, Jason Sebastian, and Greg Olson

A Study on the Effects of Substrate Crystallographic Orientation on Microstructural Characteristics of René N5

Processed through Scanning Laser Epitaxy 1041
Amrita Basak and Suman Das

Author Index 1051

Subject Index 1055

xii
 PREFACE
The purpose of the International Symposium on Superalloys, which takes place every four years, is to provide a forum
for researchers, producers, and users to exchange recent technical information regarding the high temperature, high
performance materials that are used in gas turbine engines and related products. The principal goal of the Symposium
is to highlight new initiatives and future growth opportunities for superalloys, recent advances in the understanding
of their behavior, and progress in integrating them into new systems. The first Symposium, held in 1968, emphasized
phase instabilities in superalloys. Since then, the scope of the Symposium has expanded considerably to cover all
aspects of research, development, manufacture, and application of these materials. Over the years, the Symposium
has developed rich traditions, encompassing a high quality peer reviewed publication, which is presented before the
conference, single session presentations, and lively discussions during and after formal sessions, which are facilitated
by the Seven Springs Mountain Resort.

This, the Thirteenth Symposium takes place at a time when superalloy users are striving to improve the efficiency of
power systems to reduce emissions, weight, and operating costs by using alloys that are not just capable of higher
temperatures or stresses, but are produced with lower amounts of scarce or expensive raw materials. There is also an
impetus to develop and validate alloys and products much faster than in earlier times. Increasingly, these aspirations
require computational modeling and simulations of alloy systems and manufacturing processes, and a greater depth
of understanding and modeling of material and component behaviour. Insights into the latter are often improved
substantially using observations and data from new and sophisticated experimental techniques. As demonstrated by
the examples in these proceedings, achieving incremental or step-change improvements in superalloy production,
performance, and affordability necessitates collaborative working between academia, producers, and users in the
superalloy community.

The Keynote Address of this Symposium is from Shailesh Patel and John (Jack) deBarbadillo of Special Metals
Corporation, a division of Precision Castparts Corporation (PCC). Their paper and keynote lecture provide an insight
into innovation from an alloy producer's perspective. They show examples of collaborative working at (PCC),
commenting on the successes and the challenges.

Starting with the Second Symposium in 1972, each Symposium and its corresponding published proceedings have been
dedicated to an individual as a means of honoring his or her contributions to the superalloy industry. The Thirteenth
International Symposium is dedicated to Louis Lherbier, a true pioneer and innovator in our field. Further details of
Lou's career and contributions can be found on the following pages.

Finally, it should be noted that this Symposium would not have been possible without the efforts of the current and past
members of the two committees that serve the International Symposium on Superalloys. The Program Committee for
the Thirteenth Symposium, listed below, was responsible for preparation of the technical program, including critical
review of abstracts and manuscripts for originality, technical content, and pertinence to industry. The entire Organizing
Committee, listed in the frontmatter of this book, devoted considerable effort to organizing all other aspects of the
Symposium.

We would like to also recognize the tremendous work of the TMS staff, particularly Trudi Dunlap, Louise Wallach,
Christina Raabe Eck, Jennifer Booth, and Caron Gavrish, in helping to organize a successful conference.

Mark Hardy
Eric Huron
Uwe Glatzel
Brian Griffin
Beth Lewis
Catherine Rae
Venkat Seetharaman
Sammy Tin

xiii
 DEDICATION

Louis W. Lherbier
The 13th International Symposium on Superalloys is dedicated to Louis W. Lherbier for his
substantial contributions to our field. He has been a pioneer and innovator in the development
and processing of high strength powder metallurgical and cast/wrought superalloys for gas
turbine disk applications

Lou Lherbier's career has spanned 60 years. After graduating from Carnegie Mellon University with a degree in
Metallurgical Engineering, he was initially employed by Universal Cyclops Specialty Steel Corporation (later Cytemp
Specialty Steel) for 35 years. This was followed by 5 years at Dynamet Incorporated and then approximately 20 years
at Carpenter Technology. All of that time was dedicated to specialty alloy technology, including the melting and
processing of alloys ranging from tool steels, stainless steels, and titanium to nickel and cobalt-based Superalloys.
During a large part of his career, his time was dedicated to the manufacturing of these same materials by powder
metallurgy (PM) technology.

As a young metallurgist, Lou's efforts were directed at technology issues on a wide variety of specialty alloys, none
more difficult and perplexing than the segregated structures and poor hot workability of high speed steels. When it
became apparent in the mid 1960s that powder metallurgy technology could solve the segregation and workability
problems in high speed steels, Lou recognized that the same technology could be applied to other materials including
superalloys. Universal Cyclops went on to make the first superalloy IN 100 metal powder for Pratt & Whitney, a
version of which is still used in today's jet engines.

In 1967, Lou became Manager of the R&D Laboratory at Universal Cyclops. He became involved with the development
of melting and processing procedures for manufacturing Alloy 718, to be used in General Electric's first TF39 engines.
Through melting and homogenization practices, Lou and his co-workers succeeded in eliminating black spot indications
(freckles) and Laves phase problems in this alloy. In 1976, he successfully lobbied his employer for the opportunity to
recruit a dedicated group to work exclusively on powder metallurgy technology. He also secured a number of Air Force
contracts dedicated to the development of superalloy powder metallurgy. Lou's group developed the CAP technique
(powder consolidation using atmospheric pressure in glass molds) and demonstrated the manufacture of dual-property
rotating disks by bonding a powder metallurgy hub to a cast blade ring using hot isostatic processing (HIP). The team
demonstrated that extrusion of a HIP'ed billet at an extrusion ratio of 3:1 gave equivalent results to the direct extrusion
of loose powder at an extrusion ratio of 7:1.

XV
These successes used superalloy powder metallurgy technology primarily for military engine disks. Lou saw the
potential future of PM superalloys and convinced his management to install the first large (2000 lb) vacuum melt gas
atomization facility to manufacture superalloy powders. The bright future was dramatically set back when the failure
of an as-HIP'ed disk resulted in a crash at the Farnborough Air Show in 1980. The demand for powder metallurgy
diminished temporarily, and Lou returned to being the R&D Director and later Vice President ofTechnology at Cytemp
Specialty Steel. The highlight ofthis period was the development of fine grain Alloy 718 and the understanding of the
origins of white spots. The industry did eventually develop hot working processes to produce PM components with
improved quality (in part, based on some of Lou's earlier extrude and forge window studies) and today PM parts are
extensively used across the industry in both commercial and military engines.

In 1991, Lou retired from Cytemp Specialty Steel and immediately went to work for Dynamet Incorporated, a titanium
bar and wire manufacturer. Dynamet had just purchased the powder operations from Cytemp. He became Vice President
- Technical Director and led a successful effort to develop processing technology for the alloys Beta C and Ti-6Nb,
while still maintaining a strong interest in powder metallurgy technology. Carpenter Technology purchased Dynamet
in 1997 and Lou remained as Vice President. In 2001, Lou returned full time to powder metallurgy technology as
Director ofMarket Development and Powder Commercialization for Carpenter. He has spent the last 15 years assisting
in the development ofHIP'ed near net shape parts, metal injection molding, and additive manufacturing.

Lou has given presentations throughout the world that emphasize the melting, processing, and structural characteristics
of Superalloys including those made by powder metallurgy technology. He has authored many technical articles as
well as the chapter "Melting" in the book The Superalloys (McGraw Hill, 1987). He has received a number of awards
including ASM International Fellow, the MPIF Distinguished Service Award, the ASM Pittsburgh Chapter Edgar C.
Bain Award, and an award from AVS-VMD for Technical Contributions to the Specialty Metals Industry. He was
honored by the ASM Pittsburgh Chapter by presenting the Pittsburgh Nite Lecture, and the Andrew Carnegie Lecture.
Lou has been part ofthe teams that have won three IRI00 Awards. Lou holds a number of patents involving the design
and processing of tool steels, stainless steels, and Superalloys. Last but not least, through it all, Lou has always been a
welcomed source of advice and knowledge for beginning metallurgists and his peers throughout the industry.

PAST DEDICATEES
1972 - Clarence Bieber

1976 - Falih Damara

1980 - Rudy Thielman

1984 - Gunther Mohling

1988 - Herb Eiselstein

1992 - Carl Lund

1996 - John Radavich

2000 - Wilfred "Red" Couts

2004 - Fred Pettit

2008 - Raymond Decker

2012 - Anthony Giamei

xvi
 BEST PAPER AWARD
The following paper was selected by the Awards Committee ofthe International Symposium on Superalloys
as winner ofthe Best Paper Award for the 13th symposium:

Thermal Cycling Creep Resistance of Ni-Based Single Crystal Superalloys

Jonathan Cormier, ISAE-ENSMA / Institut Pprime

The selection was based on the following criteria: originality, technical content, pertinence to the superalloys
and gas turbine industries and academic community, and clarity and style.

xvii
 Thirteenth International Symposium on Superalloys
COMMITTEE MEMBERS
General Chair Eric Huron

Secretary Tony Banik

Treasurer Gern Maurer

Program Chair Mark Hardy

Program Committee. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. Uwe Glatzel

Brian Griffin

Beth Lewis

Cathie Rae

Venkat Seetharaman

Sammy Tin

Publication Chair Venkat Seetharaman

Arrangements Chair Dave Novotnak

International Publicity Akihiro Sato

Jian Zhang

U. S. Publicity Jacqui Wahl

Student Coordination Michael Mills

Awards Committee Chair Roger Reed

Awards Committee Ken Green

Tresa Pollock

TMS Staff Liaisons Trudi Dunlap

Jennifer Booth

Caron Gavrish

Christina Raabe Eck

Louise Wallach

xix
 Superalloys 2016: Proceedings of the 13th International Symposium on Superalloys
Edited by: Mark Hardy, Eric Huron, Uwe Glatzel, Brian Griffin, Beth Lewis,
Cathie Rae, Venkat Seetharaman, and Sammy Tin
TMS (The Minerals, Metals & Materials Society), 2016

Symposium Keynote Address

 Superalloys 2016: Proceedings of the 13th International Symposium on Superalloys
Edited by: Mark Hardy, Eric Huron, Uwe Glatzel, Brian Griffin, Beth Lewis,
Cathie Rae, Venkat Seetharaman, and Sammy Tin
TMS (The Minerals, Metals & Materials Society), 2016

INNOVATION THROUGH COLLABORATION

S J. Patel and J.J. deBarbadillo
Special Metals Corporation
3200 Riverside Drive, Huntington, WV 25705

Keywords: Superalloys, Gas Turbines, Collaborative R&D

Abstract The Whittle engine and the Gloster Meteor aircraft it flew on did
not win the war for the Allied Forces, but they sparked the
The history of superalloys and their enabling role in aircraft incredible co-development of superalloys and aircraft turbine
propulsion has been a remarkable saga of technical innovation and technology for military and later commercial aircraft. The early
collaboration in a never ending quest for improved performance history of superalloy development is described in detail by
and economy. This has been achieved in an environment of fierce Betteridge [3] and Sims [4],
competition between Original Equipment Manufacturers (OEM's)
and between their material suppliers. Through the years, notable The WW II era was a period when technology was shared freely
collaborative activities have occurred involving companies, between companies and especially between the US and UK. A
government laboratories and agencies and universities. The duplicate of the Whittle W.1X engine was delivered to the GE
industrial and political environment and its influence on plant in Lynn, Massachusetts where it was further developed into
collaboration have evolved from the inception of the technology the GE I-A engine that flew on the Bell P-59 in 1942 [5],
in WW II through the cold war era to the current era with the Pioneering alloy developers such as Clarence Bieber, Gunter
spread of technology throughout the world. This paper reviews Moehling, Rudy Thielemann as well as Leonard Pfeil and his co-
this history through a modern perspective and uses examples to workers developed many of the iconic superalloys using largely
point to the future of collaborative innovation. empirical methods. In an interesting (and rare) paper, presented to
the Philadelphia ASM chapter, Bieber describes his innovative
Introduction alloy development techniques [6].

The conception of age-hardened nickel-chromium alloys is This open era changed in the late 1940's as the world transitioned
attributed to Merica in the US and Chevenard in France in the late to a Cold War mentality. Military aircraft performance continued
1920's, but a strong commercial need for the materials did not to drive superalloy technology which developed rapidly in the US,
exist at that time. The real start of the superalloy age began in the UK, France and Russia. Much of the development in the US was
UK with the Whittle gas turbine engine. Sir Frank Whittle, shown sponsored or inspired by the Department of Defense (DOD) and
with his demonstration WU engine in Figure 1, realized that the later National Aeronautics & Space Administration (NASA), both
stainless steel blades that he initially employed were not of which built extensive research facilities. International Nickel
sufficiently durable to sustain practical flight missions. Ltd. also built large research centers in the US at Sterling Forest,
New York and in the UK in Birmingham. Inco's goal was to
develop markets for nickel, and in the process, broadly shared
technology. With a need to understand the basic science of
superalloys, universities began to make important contributions.
The work of Decker and Freeman at University of Michigan that
demonstrated the value of Β and Zr as grain boundary
strengtheners is an example [7]. The Seven Springs conference
came into being in 1968 as an industry forum to discuss phase
stability in superalloys [8], This was the "golden age" of
superalloy technology innovation. All of the major alloy
paradigms and process innovations germinated or were adopted
between 1950 and 1970. These include vacuum melting,
remelting, powder atomization, directional solidification,
isothermal processing, mechanical alloying, electron beam
welding, coating, internal cooling and even the additive
Figure 1. Sir Frank Whittle with a bench scale model of his gas manufacturing concept.
turbine engine (Google Images).
In this period, more formal collaborations were developed, often
In 1940 Whittle wrote to Leonard Pfeil, Research Director at the led by US DOD or NASA and aimed at furthering aircraft
Mond Nickel Company (later Inco), requesting that he develop a performance, but occasionally dealing with issues such as raw
superior alloy meeting 800°C tensile and creep requirements. Pfeil material shortages. In this pre-internet world, intellectual property
improved the creep strength of an existing Ni-Cr alloy by adding (IP) security was primarily a matter of controlling the movement
sufficient Al and Ti to enable γ' formation. He thereby created the of people and paper. DOD and NASA projects had various levels
first superalloy, later designated NIMONIC® alloy 80 [1, 2], This of security, but control via ITAR was relatively straight forward
alloy was used in Whittle's second flying engine in 1942. (but not leak-proofl). Technical papers by industry technologists
were common as companies endeavored to publicize their
©NIMONIC and INCONEL are trademarks of Special Metals. developments and government technical reports were relatively

3
accessible. A strong collegial environment developed among be enhanced. The examples are by no means exhaustive; they
technologists in the industry despite the fact that they worked for were selected to illustrate different forms of successful
competing companies. A large number of patents were filed collaboration.
during this era, and with rapid adoption of new technology at the Examples
time, there was the expectation that by the time they had expired,
technology would have moved on. In this time computer A new supply-chain paradigm - Intra-company Collaboration
technology was in its infancy and process sensing and data Precision Castparts Corporation (PCC) was founded in Portland in
collection was almost non-existent. The transaction between 1949 as the Oregon Saw Chain Company. Its small steel
supplier and purchaser was based entirely on testing a product to investment casting foundry was spun off as PCC in 1957. Its
verify that it met specification. General Manager Ed Cooley based his business model on being
able to make the largest and most complex castings in the
The transition to the current state was gradual and it had many industry. Cooley entered the aircraft casting business in 1965. He
facets. Some obvious ones are the rise and eventual dominance of aggressively honed his capabilities for making complex nickel and
commercial aviation as a consumer for new engine technology. titanium investment cast parts. In doing this he built a highly
This introduced a strong cost saving mentality to an industry that successful business that generated a significant return on
previously was primarily motivated by performance. Another investment [10], In 1986 PCC began to diversify when it
factor was the maturation of the technology, as the melting point purchased the TRW airfoils business in Cleveland Ohio. Later
of nickel defined a tangible limit. The end of the cold war and PCC redefined itself as a parts supplier to the aircraft engine and
globalization of the aircraft industry and its suppliers also had an then to the entire aircraft. PCC successively acquired Wyman-
influence. Economic nationalism on the one hand and Gordon (forgings), SPS (fasteners), Special Metals (nickel-base
proliferation of offsets and sponsored low cost suppliers created a alloys), Timet (titanium alloys), and Primus (airframe structural
tension that did not exist previously. During this transition many components). Wyman-Gordon and Special Metals were also
of the corporate research labs such as Inco and Climax were participants in the oil and gas, fossil and nuclear energy markets,
down-sized or closed, thus eliminating key facilitators of so this sector became a prominent part of PCC's core businesses.
collaborative efforts. Research at Air Force Research Lab To complement the capabilities of already large companies, PCC
(AFRL), NASA, and the Defense Advanced Research Projects purchased several smaller, but well-known companies, such as
Agency (DARPA) shifted from superalloys to "advanced Carlton Forge, McWilliams Forge, Rollmet and Rath-Gibson.
materials" and university research dependent on NSF funding PCC is now organized with three divisions (Castings,
followed this trend. Chet Sims addressed this issue in his invited Aero structures and Forged Products and Metals) with 162
paper at Seven Springs in 1988 [9], separate business units and 30,500 employees. The overall
structure of PCC is illustrated in Figure 2.
Another powerful driver of cultural change was the computer and
computer enabled technology. Now, vast amounts of data could
be collected, stored, analyzed and instantly transmitted to
collaborators, customers or competitors anywhere in the world.
Heavy investments by DARPA and DOD agencies in process
modeling began to bear fruit as computer memory and speed
made modeling of complex systems practical. With the maturation
of technology, the focus became more and more on process
control, resulting in highly controlled fixed practices that have
become the foundation of Integrated Computational Materials
Engineering (ICME). Concern in the US about proliferation of
technology briefly relaxed with the end of the cold war only to
strongly re-emerge after Sept 11, 2001 in the guise of preventing
proliferation to so-called rogue states and terrorist organizations.
Computer security measures implemented to combat industrial Figure 2. General organization of PCC businesses.
technology espionage have become a significant constraint to the
flow of information and to industrial collaboration. In 2016 PCC was itself purchased by the Berkshire-Hathaway
Group, under whose direction it will maintain its focus on
All of these factors, acting synergistically, have combined to providing increasing value to its customers.
change the nature of technical collaboration. The progressive
decline in the number of technical papers presented by industry While the PCC business model does not directly foster external
representatives as prime authors at this conference is a direct collaborative policy or projects, it does create an internal
result of this changing environment. Whether it is because the environment for collaborative innovation across company
new technical developments are considered not to be of sufficient boundaries not previously possible. PCC does not have a
academic value, or engineers are too busy to communicate or corporate R&D facility or function. However, it does actively
there is fear of internal IP leakage or ITAR violations, all have promote an internal virtual technical environment that develops
their influence. But that does not mean that collaboration has and shares best practices and creates multi-function teams to work
ceased, nor does it mean that it is no longer relevant to the goals on common problems or opportunities. To this end there have
of the industry. Collaborations now occur in different, more been several corporate and divisional technical conferences
constrained, ways and the results may not be reported in the open organized around a central theme with strict presentation and
literature. The following discussion is based on some recent format requirements. This has provided a forum for young
examples that show how collaboration is occurring and how it can engineers to be recognized and to develop their network among

4
their peers in other related companies. In addition, more This was not an easy scale-up of an established material. Alloy
technology specific meetings are held on a regular basis. These 706 is resistant but not immune to solidification segregation. The
include such varied topics as vacuum melting, raw materials alloy also forms a significant amount of Laves phase during
utilization, computer simulation and process automation. A solidification that results in very low as-cast ductility. The high
corporation-wide technology development program also level of residual stress in large ingots makes the alloy sensitive to
encourages peer interchange among young engineers. cracking. The initial practice was Vacuum Induction Melting
(VIM) and Electro-slag Remelting (ESR) which produced suitable
Intercompany Collaboration With No Formal Agreement - forged structure and properties, but was unreliable due to
Large Gas Turbine Wheels. Successful multi-company remelting instabilities. GE then specified triple melt (VIM-ESR-
collaborations do not always require elaborate formal agreements. VAR) on the belief that the shallower melt pool in Vacuum Arc
An example is the adaptation of INCONEL® alloy 706 for Remelting (VAR) and the improved stability provided by a sound
wheels, spacers and shafts for large frame gas turbines. This electrode would minimize the possibility of a segregation anomaly
development was carried out entirely between the OEM (General that would be impossible to detect. That change did not solve the
Electric Power) and its supply chain (melters and forgers) with cracking problem which is illustrated by an example from Special
nothing more than simple bi-lateral non-disclosure agreements. Metals (Figure 4) and described by Minisandram [16]. Each of the
melt shops developed solutions to the problem for their own
Alloy 706 was developed by Eiselstein and Clatworthy in 1970 as unique processes using thermal stress modeling to define process
a low-cost derivative of alloy 718 [11, 12]. The inventors windows. In this respect each melter worked independently with
envisioned it as a general purpose alloy; however, they were minimal input from GE.
aware that the alloy was less prone than alloy 718 to solidification
segregation. This concept was further developed by Suarez et al;
however, they were unable to identify process conditions that
prevented both segregation and ingot cracking [13]. The
possibility of using a large diameter age-hardened nickel-base
alloy for a gas turbine wheel was explored by GE at that time. The
properties of alloy 706 were considered attractive [14]. However,
for various reasons, the time was not ripe for a transition from
steel to nickel turbine rotors. Over the succeeding 20 years, the
Inco patent expired without there being a significant application.

By the late 1980's GE's gas turbine designers had pushed

operating temperatures to the limit of steel capability. GE then
initiated work with its supply chain to develop a 706 rotor
capability. Gas turbine rotors are an order of magnitude larger Figure 4. Catastrophic longitudinal cracking of a 706 ESR Ingot.
than aircraft turbine rotors and the high forging loads required to
forge these disks could only be delivered by three 50 KT+ forging Similar development was required for ingot conversion
presses at Alcoa, Wyman-Gordon and at Issoire in France. (billetizing) and closed die forging. Along the way composition
Similarly, only four nickel alloy melt shops (Allvac, Aubert & and heat treatment criticalities and ultra-sonic inspection
Duval, Carpenter, and Inco Alloys International) had the melting techniques were developed. The final result was a fixed practice
and remelting capability to produce cropped and conditioned specification that promoted a uniform product made by multiple
ingots as heavy as 15 T. While the basic equipment existed within suppliers with different equipment. Throughout this development
these companies, there were significant differences that precluded there was communication between GE and its suppliers that
a universal practice. Accordingly GE defined a set of product preserved the confidential information of each supplier. For a
criteria and then worked with the supply chain to develop multiple project of this nature to succeed, there must be a clear and
process pathways. The introduction of this product was described narrowly defined product goal with a credible revenue potential
by Schilke et al [15], and trust that confidentiality will be maintained. The 706
development left a legacy of "big ingot" technology that provided
a basis for the adaptation of superalloys for a new generation of
energy systems described in the next example [17, 18].

AUSC - Industry Consortium with Very Long Term Goals.

Historically, the primary materials of construction for coal-fired
steam boilers and coupled steam turbines which generate more
than half of the world's electricity were heat-resisting ferritic steel
grades. In the 1990's it was recognized that the operating
temperatures had reached the limit where ferritic steels could no
longer be used. The next generation of power plants that was
designed to operate at or above 700 °C would require super-
austenitic steels or possibly nickel-base alloys. Consortia were
launched in Europe (1998) and the US (2001) to develop the
material technology with the expectation that the first
demonstration plants could be built in about 2010 [19]. This
became known as Advanced- Ultrasupercritical steam technology
Figure 3. Wyman-Gordon 50 KT forging press in Grafton, MA.

5
(AUSC). The problem of developing the technology and financing scale needed for the plant. Special Metals and Wyman Gordon
of such plants proved much more difficult than initially thought. have been involved in a number of these activities in close
collaboration with the OEMs. These include extrusion of large
In the early work alloy 617, a weldable solid-solution and carbide diameter pipe and forging of steam turbine disks of alloy 282®.
strengthened nickel-base alloy with a prior history of use for Considerable work has also been done on manufacture of pipe
chemical process vessels and gas turbine transition ducts, was bends and fittings with Chicago Bridge & Iron Alloy Piping
considered a prime candidate for boiler tube and steam pipe. As a Products, and Maass Flange. These activities are described in
higher strength alternative, Special Metals proposed age-hardened more detail in another paper in this conference [25].
alloy 740, that is a modification of aerospace sheet alloy 263, with (® 282 is a registered trademark of Haynes International).
improved oxidation and coal ash corrosion resistance [20],

The US AUSC Consortium is a public/private venture comprised

of the US Department of Energy (DOE), Ohio Coal Development
Office (OCDO), Electric Power Research Institute (EPRI), and
major US boiler and turbine manufacturers. Oak Ridge National

mm
Lab (ORNL) and the National Energy Technology Lab (NETL) in
Albany Oregon provided key material evaluation capabilities. The ÉKíwLka-
US consortium evaluated many commercial and developmental
alloys for the various components in the boiler and turbine. Alloy
740 was selected for further evaluation as tube and pipe. This
alloy was later modified to improve its γ' stability and heavy
section weldability and renamed alloy 740H [21], Reviews of the
consortium activity were presented by Viswanathan et al. [22] and Figure 6. Mock-up segment of header pipe that demonstrates
Shingledecker et al. [23]. technical capabilities needed for AUSC power plant such as
production of large diameter ingot and pipe and welding of heavy
Special Metals (and other alloy producers) were not members of section and complex geometry.
the consortium, but they worked closely with members and Labs,
initially to supply material for testing and later for demonstration The AUSC consortium collaboration has been successful in a
of component manufacturing capability and to supply material for number of ways. Not only have the materials been developed and
boiler test loops. Two key properties on which material selection qualified to enable construction of an AUSC demonstration power
was based were minimum creep-rupture strength in 100,000 h at plant, but it has made these materials available to the power
760 °C and 100 MPa, and oxidation and coal ash corrosion industry throughout the world. In addition the technology is
penetration of less than 2 mm in 200,000 h. The creep testing of essential for other advanced power generation applications. In
base metal and weldments was done at ORNL while oxidation and particular supercritical C0 2 has been identified as a highly
hot corrosion testing was done at ORNL, NETL, Babcock & efficient working fluid to drive compact turbines in fossil, solar
Wilcox and Foster Wheeler. The creep test data formed a key part and nuclear power systems. Pilot plants designed to prove these
of a data package that the consortium presented to ASME for code concepts are now under construction. This initiative that began
approval. Formal code approval of the alloy in Code Case 2702 rather modestly 18 years ago will make a major contribution to
was gained in 2011 [24], Alloy 740H is the first age-hardened the world's energy future. But from an alloy developer/producer
alloy to be approved by ASME for use in welded pressure pipe for perspective, developing alloys for an application that will take a
creep-limited service. The design stress allowables, compared generation reach maturity is a very big risk.
with those of solid solution strengthened boiler alloys are shown
in Figure 5. Ma2JIC - Industry/University Center for Joining Technology
The National Science Foundation (NSF) has been a major
ASME Section It - A l l o w a b l e Stresses supporter of basic science research in the US for many years. One
300 - of its programs, the Industry/University Collaborative Research
Centers (I/UCRC), provides a framework for centers in a wide
range of technologies. The Materials and Manufacturing Joining
Innovation Center (Ma2JIC, formerly CIMJSEA) was launched in
2010 and is now in its second NSF award phase. This center is
anchored at Ohio State University with partners at Lehigh
University, Colorado School of Mines and University of
Tennessee. NSF centers require company membership fees and an
500 600 700 800 900 industrial advisory board to control selection of projects that must
Temperature (*C) be collaborative and pre-competitive in nature.
-*-Gr. 91 -*-347H i 617 —230 - tnconel 740H
(CC2702)
Metal joining is highly diversified in both technology and the
industries that utilize it. These joining processes include
Figure 5. ASME design allowable stress for 740H compared with traditional arc, laser and electron beam welding as well as brazing,
other widely used boiler alloys. friction welding and additive manufacturing. The forty members
of the Ma2JIC center include welding products suppliers, welding
The materials characterization and qualification phase of the US services companies, fabricators, users and institutions. Process
AUSC project is complete. Recent focus has been on modeling is a key part of this program. The center supports a wide
demonstration of capability of manufacturing components on the

6
range of projects involving superalloys including aerospace, gas Development of the model for nickel-base alloys is now
turbine, power and oil and gas applications. proceeding with DOE funding at Idaho National Lab (INL).

One project addresses the problem of stress-relief/stress-relaxation

cracking. This mode of cracking is seen in a wide range of alloys Solidification
in aircraft, power generation, petro-chemical, and chemical Mif rostnifture Structure
process industries. Aircraft industry readers will appreciate the Evolution Thru Fracture
Thermal Cycles Modes
often cited weldability advantage of alloy 718 versus Waspaloy. >4
Integrated
In power and chemical plants this mode of cracking is especially Long Time Methodology Environmental
insidious because it is driven by relaxation of residual welding Microstructure for Weld Life Effects
Stability Prediction
stress in large highly restrained structures by a creep rupture
mechanism. Cracking may not become evident until after years of
Time Dependent Macro
service. For example, a stress relaxation crack in alloy 617 in a Mechanical Properties Service
main steam pipe of a power plant experimental test loop was not of Composites Residual Stress
Stress
seen until after 10,000 h of operation [26]. It has been shown that Evolution
this kind of cracking can be prevented through joint design,
welding process control and post-weld stress-relief heat-
treatments. Figure 8. Structure for a model of weld behavior in power plant.

Research at Lehigh and Ohio State Universities is focused on From an industry perspective, university based collaborative
developing predictive tests and characterizing relative research has a number of short-comings, not least of which is the
performance of commercial alloys. Many of these tests are difficulty of finding common ground among participating
Gleeble-based and seek to reproduce the complex thermal and companies for a sufficiently targeted research program. Individual
stress cycles that accompany a multi-pass weld cycle. Analysis is membership funding tends to be limited, so external funding can
complicated by the problem of long time microstructure stability be critical. The success of a center often depends on the
of weldments that contain severe microstructure, composition and commitment of the industrial advisory board and its understanding
stress gradients. An example of a unique microstructure that has of the open publication needs of the university partners and a
been observed in a weld in alloy 740H is shown in Figure 7 [27]. project timeline closely tied to the student graduation cycle.
Nevertheless, a strong I/UCRC can be a fruitful employee
recruiting mechanism as members can become familiar with the
capabilities of students in a variety of settings.

Metals Affordability Initiative - Industry/DOD Partnership

The Metals Affordability Initiative (MAI) is an industry/Air Force
partnership that is dedicated to development of metals technology
for military aircraft. US companies representing four tiers of the
supply chain (airframe and systems, engines, parts suppliers and
metals producers) are members. Funding is provided through
annual appropriations by the US Congress to the USAF,
designated for industry led materials technology development. A
significant industry cost share is required to supplement federal
funding for projects. Projects are selected by a Technical
Oversight Committee (TOC) where each member company,
regardless of its size, has one vote. The TOC also monitors the
Figure 7. Grain boundary γ' denuded zone in alloy 740H cross- technical progress of the projects and controls continued project
weld creep specimen. This feature is caused by an interaction of funding through task gate reviews. Generally, work is done at
residual stress and a discontinuous γ' coarsening reaction [27]. project member companies and subcontractors that often include
small businesses and universities. A wide range of projects have
A goal of this research is to develop a comprehensive model to been completed since the MAI was started in 1999. Many of these
predict life performance of a weldment in service. Such a model projects have resulted in early insertion for supply chain
must consider multiple interacting forces as illustrated in Figure 8. manufacturing efficiency or products used on aircraft platforms
Note that many of the processes are time dependent and non- that support enhanced mission capability or operating cost
equilibrium and must contend with steep structure and property reduction. Much of the technical work is subject to ITAR
gradients. restrictions and may only be reported in closed forums. Highlights
of the program for 2015 have been reported [28].
The development of a holistic life model will be difficult and will
take several years to complete. One of the major gaps is the lack One of the most successful MAI projects resulted in the adoption
of material property data to characterize the different structural of digital radiography for final part acceptance of aerospace
zones in a weldment such as coarse grain heat affected zone, or castings. Most aerospace structural castings require radiographic
across a dendrite in an un-homogenized structure. An NSF funded inspection to confirm internal quality. In the late 1990s the
basic research project at Ohio State University is addressing this adoption of digital radiographic imaging transformed the medical
problem using a variety of novel micro-mechanical techniques. industry. As personal and industrial photography followed suit,

7
film became scarce and expensive. Other reasons for interest in ICME has profound implications for the way industries
digital records are portability and permanence. collaborate. The concept involves linking process models to
reduce variability of material properties, reduce rejections and
Although there was widespread interest in the casting industry in improve the accuracy of life prediction. While process modeling
making the conversion from film to digital, there were major is now strongly embedded in superalloy production technology
barriers that could not be overcome by one company acting the incentive to link models to achieve a holistic predictive ability
independently. PCC and Howmet made an initial start under the has been lacking. The Air Force has invested heavily in ICME
Next Generation Manufacturing Technology Initiative (NGMTI), following a National Academy of Science Report in 2008 [30].
but funding from that source was insufficient. PCC then put The ICME work builds on the long history of Air Force support
together a team and proposal to MAI that was approved and got for finite element modeling that accelerated the development of a
underway in 2008. The project was also supported by DoD robust simulation industry in the US. Many projects within the
Manufacturing Technology Program (ManTech). The PCC-led MAI portfolio now address some aspect of ICME including the
team included all of the stakeholders among the casting suppliers, one just described. Projects under the MAI mantle include
OEMs and key film and equipment suppliers. Among the prediction and measurement of residual stress caused by forging,
problems to be overcome were 1) lack of digital reference images, heat treatment and joining, its effect on part distortion during final
2) lack of ASTM and company specifications, 3) competing machining, and its effect on fatigue properties. More fundamental
commercial image systems and 4) need for NDT inspector programs are considering the evolution of microstructure and its
training from shooter level all the way through Level III. In many effect on the properties in forged parts. These models have been
cases this involved decades of experience with film and lack of validated and the uncertainly quantified. Work is now underway
familiarity with computers. Another barrier was the high cost of to determine the sensitivity to process variables and to develop a
acquiring digital radiographic equipment that was sufficiently platform, data format and security controls that will enable
robust for foundry use. establishment of a digital data thread. This exposes an unresolved
point of contention between oversight agencies, system owners,
OEMs and parts/material suppliers regarding collection and
FOREIGN MATERIAL LESS DENSE 1 / 8 in. (3.2 mm| handling of proprietary process data in a digital world.

The MAI concept has been very productive. The most recent
assessment of Return on Investment (ROI) to DoD is $1.18 billion
for a government investment of $160 million [31]. Executive and
technical meetings are held quarterly with strong membership
participation. This is in part the result of the required financial
participation of the members, an obligation to involve a broad
cross-section of the supply chain in each project and a strong
business case. The active role of AFRL technical personnel is also
beneficial. The principal problems have been a primary funding
source subject to political uncertainties and the complexities
associated with management of multi-participant government
funded contracts.

Figure 9. X-ray radiographic image reference standards for SMPC - An Industrial Consortium for Remelting Research
aerospace parts. Collaboration in process research is less common and what work
is done is less well known because of the specialized nature of the
The project was completed in 2011, culminating with the issuance technologies and a reluctance to publish results. A program that
of ASTM E2033 (Standard Practice for Computed Radiology). A has been underway in the US for twenty-five years is the
30 page procedure document for managing the differences Specialty Metals Processing Consortium (SMPC). Frank Zanner,
between the two major systems for capturing images was agreed working at Sandia National Lab (SNL), approached the US
and implemented by each member. Training classes were specialty alloy melters with the notion of creating a consortium
developed and delivered to all levels of NDT operator. that would focus on advanced melting technologies. Sandia hosted
Comparative images were made of parts for each customer. After a liquid metals laboratory with extensive experience in remelting
completion of the work, the project received the Defense of specialty alloys for the nuclear weapons industry. DOE funding
Manufacturing Technology Achievement Award in 2011. for enhancing domestic manufacturing technology was available
Foundry conversion to digital radiography at PCC Structural at that time. Bob Torcolini of Carpenter Technology led the
Castings Division is well underway, with some locations having difficult task of creating a consortium of highly competitive
completely removed film processors. The project was reviewed by companies. Ultimately a Delaware Membership Corporation of 13
Brayshaw and Barrett [29]. The same project team is now companies was founded. This corporation executed a Cooperative
working on the next step in digital radiography, Assisted Defect Research and Development Agreement (CRADA) with Sandia
Recognition (ADR). To date several software companies have (and later with NETL) to create a framework for projects to be
demonstrated algorithms that meet the ability of a human operator carried out by Sandia, Los Alamos and university subcontractors.
to detect discontinuities in digital x-ray images. The ability to Funding was by membership fees, in-kind support and
share digital defect maps is a critical link in ICME for aerospace Department of Energy (DoE) and later Federal Aviation
castings. Administration (FAA), United States Air Force (USAF) and
United States Navy (USN). A broadly based research program in
ESR, VAR and EB hearth melting processes was developed that

8
used the resources of the national labs with critical validation on the current generation of sub-sonic commercial aircraft engines.
industrial equipment. An example of this work is a unique This project also exemplifies many other ambitious US aerospace
experiment on a specially built hearth window installed in a VAR projects that, while not always accomplishing their platform goal,
furnace shown in Figure 10. Classic images of VAR cathode spots never-the-less made important contributions to superalloy
and drip shorts were obtained that fundamentally changed the way technology.
the process was viewed [32].

Figure 10. View through hearth window of the arc in VAR.

Tungsten reference post in the foreground [32],

Throughout its history, SMPC has generated many patents,

publications, process tools and process understanding for its
Figure 11. NASA artist concept drawing of the HSCT; a plane
members. These include defect characterization [33], VAR
that never was paved the way for a new generation of powder disk
process models [34], advanced controllers [35], process monitors
alloys (NASA Website).
[36], instrumentation and visualization and statistical analysis
tools. Although the grand objective of commercializing new
The NASA mission requirements included a long liftoff stage to
remelting processes or controllers has yet to be achieved, SMPC
achieve cruising altitude with sustained operation at 650°C.
research has had a significant impact. There has been a
Existing powder disk alloys could not meet the dwell-fatigue or
progressive reduction in the number of anomalies that have been
creep properties needed for service. ME3 (Ni-20.6Co-13Cr-3.4Al-
detected by ultra-sonic testing in rotor quality alloy 718 and
3.7TÍ-2,4Ta-0.9Nb-2.1W-3.8Mo) [37] was the resultant alloy
Waspaloy bar produced in US melt shops since data collection
designed in the NASA/General Electric/Pratt & Whitney High
began in 2002. Data reported on a confidential basis to FAA and
Speed Research/ Enabling Propulsion Materials (HSR/EPM) [38]
provided to the Aerospace Industries Association, Rotor Integrity
program for extended use up to 600°C to 700°C allowing for
Sub-Committee (RISC) shows 40-75% reduction in reportable
increased fuel efficiency, lower fuel burn and reduced emissions.
indications in each of the four product categories. This
The alloy was designed using statistical methods [39] and
improvement is due to many factors, but the shared technology
contains a high γ' content to produce balanced monotonic, cyclic
generated by SMPC is certainly one of them.
and time dependent mechanical properties [40] while still able to
be forged and heat treated. PCC has participated in this program
Melting process research poses difficult problems for
from the exploration of the thermo-mechanical and
collaboration. To begin with, process research is very costly and
microstructural properties to the development of full scale
time consuming. Consequently, with a few notable exceptions,
forgings. Applications for both sub-solvus and super-solvus heat
universities have neglected this field. Definitive validation via
treatment have been developed and are in production.
industrial experiments is critical, but sharing of the results is
awkward and constrained. Breaking into an industrial production
NASA has supported and published extensively on ME3.
schedule with risk of equipment damage is always difficult.
Resulting data available has also provided a platform for MAI
Another significant constraint is that the cost of qualifying a major
collaboration to explore and validate ICME techniques and
process change for aero-engine bar production is almost
supports efforts to characterize how variability effects the
prohibitively expensive. Hence, process data analytical tools such
predicative capabilities of these techniques.
as the SMPC VAR process monitor can be readily applied by
member companies, while more disruptive process changes such
as its novel pool depth controller are difficult to justify. Blade Cooling - A Continuing OEM/supplier Collaboration.
Modern aircraft turbine airfoils are precisely engineered to
provide optimum performance in a challenging environment. In
HSCT - ME3, a Legacy of a NASA Project. The High Speed
addition to an oriented single crystal structure with up to 75% γ'
Civil Transport (HSCT) project was conceived as the next step in
content, they contain intricate cooling channels and thermal
commercial supersonic flight beyond Concorde. The project that
barrier coatings and operate in a combustion gas well above the
began in 1990 and ended in 1999 was managed by NASA
alloy melting point. This was not always so. The first NIMONIC
Langley. It had truly lofty goals, a 300 passenger plane that would
alloy 80 blades were machined from solid forged bar. Wrought
fly at Mach 3 at 70,000 ft. for 6000 miles. In addition the engine
blade alloy technology developed rapidly: γ' content increased
would be required to have low NOX emissions and be fuel
progressively and cobalt and refractory metals were introduced.
efficient. The engine used standard turbofan technology and hence
By the time NIMONIC alloy 115 entered the market, blade alloys
had to run very hot to achieve those specifications. GE and Pratt
could no longer be cogged from ingot. Henry Wiggin Co. (Inco)
& Whitney collaborated with NASA on engine technology. While
introduced extruded blade bar and as a weight reduction measure
the project goal of commercial service by 2020 was not realized,
produced blade forging stock with leachable iron cores as early as
critical technologies were developed that are being employed in
1953 [3]. Rolls-Royce quickly recognized the value of using these

9
channels for internal air cooling and the patterns became adding new partners to the mix. All of this data can in principle be
increasingly complex. In 1970 John Benjamin at Inco's Sterling shared throughout the supply chain almost instantaneously. This
Forest Research Center developed the Mechanical Alloying brings us back to the question of IP integrity of the OEMs and
process as a solid state powder processing method for making an supply chain. Several groups are working to develop data sharing
oxide dispersion strengthened superalloy [41]. The application technologies, but this remains a high level concern for suppliers.
goal was an aircraft turbine blade where the oxide dispersion
would supplement γ' to provide creep strength up to the melting Discussion
point of the alloy. Over the next twenty years Inco invested
heavily in this technology. A significant application developed for Clearly innovation and collaboration has driven the superalloy
non-age hardened alloy MA754 in turbine vanes and bands. But industry over the past seventy-five years. This was particularly
the alloy never succeeded for the blade application despite steady true of the early years, when the pioneers of gas turbine
advancements in composition, directional recrystallization and technology and nickel alloy development fed off each other's
forging [42, 43], Despite diffusion bonded wafer blade and successes (and failures) to innovate and challenge the status quo.
lamiloy technologies, the cooling barrier could not be The various examples cited in this paper show the importance of
economically overcome in wrought alloys. this symbiotic relationship between the end user and the supplier
to solve critical problems of enabling technologies as well as cost
The early cast blades were also solid, but the foundry industry was reduction initiatives to take the industry forward. Of course the
very familiar with sacrificial metal and ceramic cores. By the time role of government is often vital, not only for the purposes of
that directional and then single crystal casting processes were funding, but also to provide national mandates and a pre-
developed, internal cooling patterns too complex for wrought competitive framework for collaboration. If we refer to the Chet
blades were already in widespread use. A relatively simple non- Sims illustration of the key periods of Superalloy evolution shown
proprietary ceramic core is shown in Figure 12. in Figure 13, the first fifty years were, in many ways, simpler
times when collaboration was often informal and exchanging
ideas and data was a matter of course, and trust.

/ ICME I
The Major Eras Process Control I =•
I I Processing
I I Al loving
I I \focuum Melting
I I The Jet Engine
11 Ί Conception ,
V- * » ' ' ' ' ' '
1940 1950 19» 19™ 1*80 1990 2000 2010
Figure 13. Update of the Chet Sims "The Major Eras" plot.
Figure 12. Complex, durable and removable ceramic cores are the
key to success of cast blade technology. As we enter the era of predictive computer modeling and ICME to
better understand our processes, improve quality, yields and lower
The progression from the earliest castings with a single central costs even further, this is no longer the current paradigm. The
cooling passage to today's complex serpentine channels with cast early days of innovating alloys and processes just to enable
wall sections as thin as 0.015 in. was continuous. The impact of engines to fly have been replaced by developing competitive
blade cooling on turbine inlet temperature is often overlooked by advantages through tightening process controls and proprietary
metallurgists, but Metham [44] and Goulette [45] attributed about data which are treated as family jewels by companies. This is
half of the advancement to cooling. Airfoil design is a closely further complicated by an evolving supplier base which is
held technology of the OEMs while the technology to consolidating and narrowing on the one hand in the US, but
manufacture them is closely held by the suppliers. This includes expanding on the other in terms of potential new suppliers from
alloy chemistry control, casting conditions, and ceramic shell and overseas. In the case of China and Japan, governments are leading
core design. Initially, cores were made at the foundry, but the the charge and funding massive investments and consortia to
manufacture of precision ceramic cores is a specialty in itself, so develop national capabilities in critical industries, reminiscent of
today many cores are manufactured to specification by post-WW II US projects. This complex landscape is encouraging
independent suppliers. a certain conservatism and in some cases, frankly, a paranoia in
many companies when it comes to IP protection. This is one of
In the 1960s airfoil designs were done as conventional the biggest barriers to successful collaborative programs in the
engineering drawings that could be passed through the supply coming years.
chain with appropriate confidentiality markings. In the modern
digital world CAD dimensional drawings become integrated with The pros and cons of industry consolidation can be debated, but
data management systems at the core maker and foundry. Casting from the perspective of an insider in the largest of these
and core making processes are designed by computer simulation, conglomerates, PCC, it is clear that the intra-collaboration
dimensions are checked and recorded with white light systems throughout the supply chain from raw materials, through melting,
and defect data collected from X-ray image recognition systems. casting, forging to final machined components is currently driving
New methods of core-making such as additive manufacturing are rapid innovation without the constraints of formal agreements and

10
IP sharing concerns. PCC's key role in the supply chain is to
convert novel ideas for products and processing concepts into 4. C.T. Sims, N.S. Stoloff, and W.C. Hagel, W.C.; Superalloys II,
actual components at an acceptable cost and quality. This would (New York, NY: John Wiley & Sons, 1987).
be much more difficult, if not impossible, in a world where
Special Metals, Timet, Wyman Gordon and Carlton, for example, 5. C.B. Meher-Homji, "The Development of the Whittle
were all independent companies. The dynamic of internal Turbojet," Journal of Engineering for Gas Turbines and Power,
customers and suppliers working together to provide solutions for ASME, 120 (1998), 249-256.
the external market is extremely potent.
6. C.G. Bieber, "Creative Metallurgy," (Paper presented at 28 th
This relationship between cost and quality is often a controversial Annual Sauveur Night Lecture, Philadelphia Chapter of the ASM,
one. On the one hand, cost reduction initiatives are critical to March 24, 1961).
maintain a competitive edge for both supplier and OEM. On the
other hand, too often the relentless pressures on the supply chain 7. R.F. Decker, and J.W. Freeman, "The Mechanism of Beneficial
to reduce costs can lead to bad decisions and a direct effect on the Effects of Boron and Zirconium on Creep Properties of a
quality of the final product. In fact, in many cases the primary Complex Heat-Resistant Alloy," Trans AIME, 218, (1960), 277-
collaborative programs between suppliers and OEM's are focused 285.
solely on cost reduction "pipelines", rather than innovative
technology ideas. This relationship needs to be rebalanced for the 8. International Symposium on Structural Stability in Superalloys,
ongoing technical health of the industry. (Warrendale, PA: AIME 1968).

Finally, the current age of electronics and computers is enabling 9. C.T. Sims, "Beyond Superalloys: The Goals, The Materials and
materials technology advancements in potentially exciting new Some Reality," Superalloys 1988, ed. S. Reichman et al,
areas, such as Additive Manufacturing. Whereas a great deal of (Warrendale, PA: TMS, 1988), 173-182.
fundamental work is already under way at research labs and
Universities, ultimately the success or failure of this technology 10. Β. Bailou, A History of Precision Castparts, (Portland, OR,
will depend on key collaborations and technology transfers March 25, 1994).
between these institutes, materials companies, component
manufacturers and OEM's. In that sense, whilst so much has 11. H.L Eiselstein, and E.F. Clatworthy, "Nickel-Chromium-Iron
changed since the early days of superalloy development, much Alloy," US Patent No. 3,663,213, May 16, 1972.
remains the same.
12. H.L. Eiselstein, "Properties of a Fabricable High Strength
Conclusions Superalloy," Metals Engineering Quarterly (1971), 20-25.

Whereas the need for continued collaboration across the 13. F.S. Suarez, J.E. Roberts, and L.D. Schley,1975, "Ingot Size
Superalloy world is clear, many challenges need to be faced and Optimization in a Superalloy - INCONEL alloy 706," Fifth
addressed. The issue of Intellectual Property protection is one of International Symposium on Electroslag and Other Special
the most critical of them. This is a core concern of many in the Melting Technologies, (Pittsburgh PA, Carnegie Mellon Institute
industry, and it may be driving behaviors within companies. This for Research, 1975)), 126-149.
concern is real and needs to be addressed if meaningful
collaboration is to continue between competitive companies. On 14. A.M. Johnson, and K.E. Fritz, "The Properties and
the other hand, supply-base consolidation has removed these Microstructure of a Large Forged Turbine Wheel", Superalloys:
barriers within companies under the same parent and so Metallurgy and Manufacture, ed. B.H. Kear et al, (Baton Rouge,
innovation is alive and well! LA: Claitors Publishing Division, 1976), 25-36.

Acknowledgements 15 P. Schilke, J.J. Pepe, and R.C. Schwant, "Alloy 706 Metallurgy
and Turbine Wheel Applications,", Superalloys 718, 625, 706 and
The authors acknowledge the contributions of Jim Barrett (PCC Various Derivatives, ed. E.A. Loria , (Warrendale, PA:TMS,
Structural Castings), Larry Graham (PCC Airfoils), Beth Lewis 1994) 1-11.
and Noshir Bhathena (Wyman-Gordon) in the planning and
writing of this manuscript. 16. R.S. Minisandram et al., "Thermal Cracking of Large
Diameter 706 Ingots," Superalloys 718, 625, 706 and Various
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20. G.D. Smith, and H.W. Sizek, "Introduction of an Advanced 34. L.A. Bertram et al., "Quantitative Simulations of a Superalloy
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12
 Superalloys 2016: Proceedings of the 13th International Symposium on Superalloys
Edited by: Mark Hardy, Eric Huron, Uwe Glatzel, Brian Griffin, Beth Lewis,
Cathie Rae, Venkat Seetharaman, and Sammy Tin
TMS (The Minerals, Metals & Materials Society), 2016

Session 1:
Alloy Development I
 Superalloys 2016: Proceedings of the 13th International Symposium on Superalloys
Edited by: Mark Hardy, Eric Huron, Uwe Glatzel, Brian Griffin, Beth Lewis,
Cathie Rae, Venkat Seetharaman, and Sammy Tin
TMS (The Minerals, Metals & Materials Society), 2016

ALLOYS-BY-DESIGN: TOWARDS O P T I M I Z A T I O N O F C O M P O S I T I O N S
O F NICKEL-BASED SUPERALLOYS

Roger C. Reed 1 , Alessandra Mottura2, David J. Crudden1

'Department of Materials, University of Oxford, Parks Road, Oxford, OX1 3PJ, UK
2
School of Metallurgy and Materials, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK

Keywords: alloy development, nickel-superalloy, materials genome

Abstract of both single crystal and polycrystalline nickel-based superalloys

for turbine blade and disc applications respectively.
The composition of a range of different nickel-based superalloys
are isolated using theory-based computational modeling, termed
'Alloys-by-Design' methods. Each alloy has been designed with Description of Alloys-By-Design Method
different applications in mind. A polycrystalline alloy is designed
for turbine disc applications, here emphasis is placed on the Typically, superalloys contain as many as ten different alloying
composition dependence of strength. Examples of the design trade- elements, to confer the desired combination of properties [4],
offs faced when increasing alloy strength are presented. Three new Commonly Cr, Co, Al, Ta, Ti, Nb, Mo, W are present; sometimes
single crystal alloy compositions are designed. They are (i) a Re and Ru are also present in the case of single crystal alloys. To
second generation type alloy with a reduced level of rhenium, (ii) a provide grain boundary strengthening C, Β and Zr are added in the
creep resistant alloy designed for high performance jet applications case of polycrystalline alloys.
and (iii) a low cost corrosion resistant alloy designed specifically
for industrial gas turbine applications. In each case the newly The large number of possible alloying elements and their
designed alloys have been manufactured. Design critical properties considerable solubility in nickel mean that the extent of the possible
are measured and compared with modeling predictions to test the alloy design space is very considerable. Moreover, the
accuracy of this alloy design approach. contributions made by each element to the microstructure and
properties are not independent of each other, so that alloying alters
Introduction the balance of properties in a subtle way which is difficult - maybe
impossible - to judge by rules-of-thumb. This situation has
Traditionally, our industry has relied upon a relatively small contributed to the present state-of-the-art in which existing alloy
number of superalloy compositions. Why? Due to an emphasis on compositions have been chosen empirically, for example using
trial-and-error procedures it has been usual to proceed via statistical analysis of experimental data. Thus considerable use has
campaigns involving the melting of between 10 and 100 heats, been made of trial-and-error based testing, and ranking of alloy
followed by their ranking using experimental testing. Rules-of- performance on the basis of measured rather than predicted
thumb and prior experience have been fed in at an early stage, to behavior. The ABD approach - involving large-scale
decide upon the compositions to be tested. This implies an computational calculations to systematically search a broad
empirical approach, necessitated by the relative immaturity of alloy compositional range - provides a potential solution to this problem.
theory and modeling capability.
Description of Alloy Isolation Procedure: The algorithm used is
Today the situation is different. Alloy theory is rather more illustrated schematically in Figure 1. It relies upon a series of
advanced; modeling methods are available on different procedural steps represented by the boxes linked by arrows. The
lengthscales: the electronic, atomistic, microscopic and important, overarching strategy is to estimate the composition-
mesoscopic. Databases of critical parameters are widely available, dependence of the mechanical behavior and environmental
for example based upon CALPHAD techniques, which whilst not performance. In this sense it relies upon brute, computational-force.
yet totally accurate are becoming of increasing usefulness. Required in practice - at minimum - are many tens of thousands of
Computational resources are rather cheap and plentiful. But the calculations.
above does not necessarily mean that modeling approaches have as
yet superceded the empirical route, or that they ever will The first step therefore - see Figure 1 - is the definition of an
completely. elemental list and associated upper and lower compositional limits
for each one, for example Table I. The second step makes use of
In this paper, a modeling-based approach termed 'Alloys-by- thermodynamic calculations made using the CALPHAD method,
Design' (ABD) [1] is proposed for the isolation of new grades of specifically using the Thermo-Calc software package and an
nickel-based superalloys, circumventing the traditional empiricism. associated database of thermodynamic parameters, in this case the
The method combines computational thermodynamics with sub- Thermotech TTNÍ8 database. For each trial composition, an
models which estimate design relevant material properties. The estimate is made of the fraction and composition of the
sub-models - referred to as merit indices - are physically based and strengthening γ' phase at equilibrium, and the associated
include properties such as creep resistance [1] and yield stress [2], composition of the matrix phase. Other thermodynamic quantities
see [1-3] for a more detailed description of the merit indices such as chemical potentials - which are needed for estimation of
included. The ABD approach has been used to isolate compositions the susceptibility to oxidation - are determined and stored at this
point. It is also convenient to estimate kinetic parameters such as

15
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suppressing discoveries which were not patented. But, assuming
that to be possible in some cases, it operated even now, for it was
well known that Patents were bought up for the purpose of being
suppressed, and it was understood also that inventors were the
persons who derived the least advantage from their inventions. His
conclusion, therefore, upon the whole matter was that the time had
at last arrived—even if it had not arrived some time ago—at which
the public interest would be promoted by the entire abolition of the
present system of monopoly.
[This speech and the succeeding one have been obligingly revised
for the press by the speakers.]
 SPEECH OF THE RIGHT HON. LORD
STANLEY, M.P.
Lord Stanley said that, agreeing substantially in the arguments of
the honourable and learned gentleman who had just sat down, he
should not have troubled the House if it had not been for the
circumstance that he was chairman of the Royal Commission which
sat upon the question of the administration of the Patent-Law some
years ago, and he thought, therefore, that it might be expedient he
should state what was the result which that inquiry produced upon
his mind. There was no doubt that, quite apart from the principle of
the law, the details of the law, as at present administered, were not
satisfactory; and, if the law were to continue in any form, he believed
that in the report of that Commission various suggestions would be
found by which the most prominent objections to its present working
might be removed, and fair trial might be given to the principle itself.
But it was impossible to carry on an inquiry of that kind, even limited
as it was—it was impossible, at least, for him, and he believed he
was not the only one in that position—without finding a doubt raised
in one’s mind whether any Patent-Law could be framed in such a
manner as not, upon the whole, upon the balance of good and evil,
to do more harm than good. That conclusion, he was bound to say,
was totally opposed to his earliest impressions upon the subject. He
resisted it for some time, but the more he had to look into this matter
—the more he had to consider how great were the practical abuses
and inconveniences of the existing system, and how difficult it would
be to remedy them—the more clearly it appeared to him that the evil
was really irremediable, being inherent in the principle itself. On this
subject of Patents there had been a certain amount of prejudice,
particularly in the minds of literary men, who appeared to think that
Copyright was only a modification of the same principle, and that if
Patents were abolished Copyright would follow. The analogy seemed
a plausible one, but he thought that, on being looked into, it would
not hold water. The difference was simply this: He did not rest it on
any abstract ground as to the distinction between invention and
discovery, but on the obvious fact that no two men ever did or ever
would write, independently of one another, exactly the same book;
each book, be it good or bad, would stand alone; whereas it might
happen, and often did happen, that two or three men, quite
independently of one another, would hit upon the same invention.
That alone established a distinction between the two cases. He was
not disposed to place the objection which he entertained to the
system of Patents upon the ground of any abstract impropriety in
giving a man a property in ideas. To a certain extent you did in the
case of Copyright recognise a certain qualified and temporary
property in ideas; and if it could be shown that a man’s ideas had
been of a nature to add greatly to the wealth of the country, he did
not think that any abstract considerations of the kind mentioned by
the honourable member (Mr. Macfie) would induce anybody to
grudge to such a man any reward to which he might fairly be entitled,
provided that that reward could be given in a manner free from
objection on other grounds. The objections which he felt to the
principle of Patents were threefold. In the first place, you could
hardly ever secure the reward going to the right man. In the next
place, you could not establish any proportion between the public
service rendered and the value of the reward received, nominally, for
that service. And, thirdly, you could not by any arrangement that he
had been able to discover, prevent very great inconvenience and
injury being inflicted upon third parties. With regard to the first point
—the difficulty of securing that the reward should go to the right man
—it must be remembered that a Patent did not, as some people
supposed, bring to the holder of it an immediate pecuniary
recompense. All that it did was to give him a right to prevent any one
else from using his invention without paying for it, and if that Patent
were infringed he was entitled to take legal proceedings. But
everybody knew that law was costly, and that Patent suits were the
most costly of all. It was notorious that Patents were continually
infringed by persons who well knew they were infringing them, but
relied upon the inability of the inventor to incur the expense of
defending his property. If a poor inventor took out a Patent, and the
Patent promised to be productive, in nine cases out of ten he was
obliged to sell it to some one who could command capital enough to
defend it in a court of law. If the Patent remained in his own hands, it
was quite sure to be infringed, and then he would probably be
crushed by the law expenses. He did not know whether it would be
possible to obtain accurate information upon this point, but he really
did not think he should be exaggerating if he said that in nine cases
out of ten—probably in 99 out of 100—the reward was obtained, not
by inventors or their representatives, but by persons who had bought
the Patent on speculation and at a very low rate. He said at a low
rate, because there was a great deal of uncertainty about such
property, and until a Patent was tested by actual working you could
hardly say whether it was valuable or not. What was the practical
effect of this? Why, that a few great firms in any branch of business,
buying up at a low rate any new Patent applicable to their business,
and prepared to fight for it, could so hamper other competitors as to
secure a practical monopoly. The reward, therefore, did not, as a
rule, go to the men who, on the ground of the public service
rendered by them, were intended to receive it. As to the second point
—that the reward might be great and the public service very small—
that had been dwelt upon by the honourable and learned gentleman
opposite, and little need be added to what had been said by him.
The merit and novelty of the invention might in many cases be
almost nothing, and, yet however obvious it might be, however much
it might lie, so to speak, in the high road of discovery, if it applied to
any article of general use, the pecuniary reward derived from it might
be absolutely out of proportion to the novelty or value of the
invention. It would be easy to give instances, but he apprehended
that the fact was familiar to every one who had studied this question.
Then, with regard to the injury to third parties, it commonly happened
that half-a-dozen men who were competing in the same line of
business were upon the track of the same discovery. Each of these
half-a-dozen men would probably have hit upon the invention which
was wanted, independently and without communication with the
other. But the first who hit upon it, and who took out a Patent for it,
was thereby entitled to exclude the general public and competitors
from the use of that which, if he had never existed, they would
probably have hit upon within a few weeks. A and B reached the
same point, one a week or a fortnight before the other, and A
became entitled, by the mere accident of such priority, to exclude B
from a process which, a little later on, B would have hit upon for
himself. Another case was that where the successful working of a
process depended not upon one, but upon several successive
inventions. The first two or three, not leading to any immediate
practical result, might not have been thought worth patenting. The
last link in the chain gave to the whole their commercial value, and it
was the person who took out the Patent for the last invention who
got the benefit of the whole, yet it might not be the most important
invention in the series. He would say nothing of the inconvenience
and prejudice to manufacturers in general. That was obvious
enough, and the question was whether there was any
counterbalancing advantage. These were the considerations which
led him to the conclusion that it was impossible to defend our system
of Patent-Law as it stood. At the same time, he did not at all disguise
from the House that there were certain inconveniences and
difficulties in the way of abolishing Patents altogether. You had to
guard, in the first place, against the danger of encouraging inventors
to keep their discoveries entirely to themselves. In some branches of
business, no doubt, that would be possible, and the obvious effect
might be to shut out the public, for a much longer period than would
be the case if Patents were allowed, from the use of some valuable
invention. Then it had been suggested by the honourable member
who raised this debate that there might be a system of State rewards
for the encouragement of really meritorious inventions. Without
putting an absolute negative on that plan, he must observe that it
was one which could only be established at great cost, and it would
be a very difficult thing to apportion among inventors the rewards to
which they might think themselves entitled. The distribution of the
rewards would give rise to endless complaints, and would occasion,
however unjustly, suspicions of jobbing and partiality. With regard to
the suggestion thrown out by the honourable and learned gentleman,
of the possibility of granting Patents, not as a right, but as matters of
discretion only in certain limited and important cases, the Select
Committee considered that point, and he was bound to say that the
difficulty of carrying it out appeared to his mind almost insuperable.
There would be found great difficulty in drawing the line, and it would
not be an easy matter for any one to exercise so large a
discretionary power as to decide to what inventions Patents should
or not be granted. He did not know what tribunal would be fit to
exercise so great an authority, and he was sure that none would be
able to exercise it in a manner to give satisfaction to the public. The
most fit persons to decide in such a case would be the first to see
the difficulty of deciding on any intelligible principle, and would on
that ground decline to undertake the duty. Under these
circumstances it appeared that they were landed in a position of
great embarrassment. He was convinced that the Patent-Laws did
more harm than good, and if called on to say aye or no as to their
continuance, he should certainly give his vote against them; but, as
this was a matter which required particularly careful handling, he
should be content to leave the question in the hands of the
Government, and he thought it was well worth consideration whether
they could not, starting on the ground that the abolition of the Patent-
Laws, wholly or partially, was desirable, institute some inquiry with
the view of discovering, if possible, the best substitute for them in
certain cases.
 PATENT RIGHT.
Paper by Mr. J. Stirling, Presented to the Glasgow Chamber of
Commerce, and published by permission.
First: Patent-right cannot be defended on the ground of justice.
The object of a Patent-Law is to establish a “property in ideas:” but
this involves the double fallacy that thought can and should be
appropriated. The end of all law is to ensure the universal freedom of
human action. Hence the law of property secures to every man the
product of his own labour. It gives to each an exclusive right to the
material embodiment of his productive energy, to be possessed or
alienated by him at will. But in so doing it leaves unrestricted the
productive energy of every other man. The freedom of one (as
represented by his property) is thus consistent with the freedom of
all.
But thought cannot be appropriated. In thought there is no material
product to be made the object of a proprietary right. There is no
“thing” to be possessed or alienated. The law can only, therefore,
give the exclusive use of an idea to one person by injuriously limiting
the intellectual activity of all others. A Patent-right, therefore, is less
a “property in ideas” than a monopoly of thought.
Again, a true right of property is universal in its application; it
extends to the products of all industry, however humble. But it is
instinctively felt, that a proprietary right applied to every individual
idea would be essentially absurd. Patent-Law, therefore, is
essentially partial in its application. It picks out certain favourite
ideas, and confers on them an anomalous and oppressive privilege.
There seems no good reason why the ideas of inventors should be
especially favoured. An invention is a means to a special end, and
should be recompensed by him who has the end in view. If any ideas
deserve a public recompense, it is those general ideas whose
application is of universal utility. But Patent-Law ignores the
discoverer of general ideas, and while conferring rewards, at the
expense of the community, on empty schemers and puffing
tradesmen, it passes over the services of a Newton or an Adam
Smith. The law of Copyright, indeed, gives to the philosopher a right
of property in his published and material works, but it leaves (most
justly) his ideas to be used and elaborated by whoso can and will.
Again, Patent-Law is founded on a conventional, not a natural,
right. It is not, like the ordinary law of property, based on an universal
intuition of the human conscience, but it is one of those laws by
which unwise legislators have striven so long and so vainly to give
an artificial stimulus to human industry. Hence the arbitrary nature of
its enactments. The ordinary right of property is unlimited in its
duration—passing from generation to generation. But common
sense revolts, instinctively, against a perpetual monopoly of thought.
A Patent-Law, therefore, can never be more than a weak
compromise with principle—the legislator undertaking to secure to
the patentee his ideal property during the biblical term of seven or
fourteen years. Now, if the inventor have a right at all, he has a right
to more than this. To cut down a real and acknowledged right of
property to seven, or even fourteen, years were a grievous wrong.
Patent-right goes too far, or not far enough. Either a Patent is no
right at all, or it is a right for all time. If ill-founded, it is a robbery of
the public; if well-founded, of the patentee.
Mere priority affords no good ground for the exclusive right to an
invention. The free exercise of thought is the common right of all.
Wherefore if A excogitate a principle to-day, and B, by independent
thought, excogitate the same principle to-morrow, both have an
equal right to benefit by the discovery; and A has no natural right to
debar B from the legitimate fruit of his intellectual effort. It may be
even that A had no real priority of thought, but was only more
knowing, more greedy, or was simply nearer to a patent office, and,
though latest in arriving at the idea, was the first to secure a legal
monopoly of its use. To found a right on such a race for priority is
evidently irrational. The simultaneousness of discoveries and
inventions by different minds, is a well-established fact in the history
of science. Certain facts and reasonings, all tending in a given
direction, are before the world. These act simultaneously on various
minds, and produce in each the same development of thought. Now,
with what justice do we pick out one of these many thinkers and give
him a monopoly of the common thought? Nor is the injustice
confined to the original idea, of which we grant a monopoly. By tying
up one idea, we stop the whole course of thought in a given
direction, and thus interfere generally, and to an indefinite extent,
with the intellectual activity of other men.
The inventor benefits by the ideas of the community, and has,
therefore, no right to a special privilege for his idea. The universal
thought of mankind is a common good; all benefit by it freely, and all
are bound freely to contribute to it. Every thinker owes an
incalculable debt to society. The inventor has the benefit of all
foregone human thought, of all existing civilization. He has the
unbought advantage of all laws, all language, all philosophy. He has
the free use of all the methods and appliances, spiritual and material,
which have been painfully elaborated by the thinkers and workers of
all time. Why, then, should he alone have an exclusive privilege, in
respect of the infinitesimal addition which he may make to the work
of ages?
Secondly: Patent-right cannot be justified on the lower ground of
expediency. The object of a Patent-Law, in the supposed interest of
the community, is to stimulate invention. But invention needs no
artificial stimulus. Nature has amply provided all needful and
wholesome encouragement, in the additional profit afforded by
improved methods of production. In the natural course of business,
every producer is spurred on by his material interests to invent for
himself or to encourage the inventions of others. The whole history
of industrial progress is an unceasing striving after improvement,
with a view to profit. The few thousand patented inventions are as
nothing compared with the innumerable improvements produced
daily and hourly in the ordinary course of business, with the vulgar
view of gain. The best stimulus to invention, therefore, will be found
in the natural competition of producers; but Patent-Law destroys this
competition by an unjust monopoly, and thus tends indirectly to
weaken the natural impulse to improvement.
 Invention may be even over-stimulated. In all her arrangements,
Nature provides for a due equilibrium of powers and tendencies.
Thus the various faculties and temperaments of man—the sanguine
and the cautious, the speculative and the practical—are nicely
balanced. The result, when things are left to themselves, is a happy
combination of ingenuity and caution, and, as a consequence, a
continuous but prudent course of improvement. But if, by
conventional rewards, we give a factitious impulse to the inventive
faculty, we destroy the natural equilibrium of capacities, and foster a
scheming, fanciful turn of mind, at the expense of thoroughness and
a patient working out of sound ideas. This result has actually
occurred in the United States, where the factitious value attached to
invention has tended to produce an almost total sacrifice of solid
workmanship to a flimsy ingenuity.
Patent-Law does not even attain its proposed end of quickening
the progress of real improvement; on the contrary, it is found in
practice seriously to hinder it, the monopoly granted to one inventor
necessarily obstructing the progress of every other. Hence, an
eminent inventor has lately said: “The advance of practical science is
now grievously obstructed by those very laws which were intended
to encourage its progress.” That Patents seriously obstruct the
natural development of ideas, is best seen by the sudden advance
which usually follows the expiry of important Patent-rights. The
natural course of improvement, dammed back by artificial obstruction
during the continuance of the Patent, is set free on its conclusion,
and a new impulse is given to the development of ideas and their
practical application.
But the public is not the only sufferer by Patent-right. Without
doubt the heaviest evil falls on the patentee. The inventor is led to
give an excessive development to his talent, and is seduced into
reliance on a law that can give him no substantial protection. The
difficulty of defining original inventions is a practical bar to a
satisfactory Patent-Law. The whole history of Patents is a long-
continued story of litigation and disappointment; and the more
admirable the invention, the greater is the certainty of difficulty and
loss. It must be a worthless invention that the patentee is left to enjoy
in peace. Whenever a Patent is worth pirating, the inventor may
depend on being involved in a maze of litigation that disturbs his
peace and ruins his fortunes. And the more the Patent privilege is
extended, the worse the evil becomes; the intricacy and the
multiplicity of details baffling every attempt to define the rights of
competing inventors.
At this moment the heaviest complaints against Patents come
from our great inventors. They repudiate the proffered privilege as
“injurious to inventors,” and complain of being “borne down by an
excess of protection.” As is natural, they who are most occupied with
the advancement of invention, feel most acutely the grievous
obstructiveness of the Patent-Law. Not enough that they have to
battle with natural difficulties; at every step they meet obstructions
which a well-meaning but perverse law places in their way. Nor do
these obstructive privileges confer any real advantage on the empty
schemers whose monopoly they establish: they merely give them the
vexatious power of hindering the progress of better men. The mere
“pen-and-ink inventor” has neither the energy, nor the perseverance,
nor the practical ability to mature his crude “idea;” but to this man the
law awards the dog-in-the-manger privilege of effectually obstructing
the natural progress of practical improvement.
These practical evils the advocates of Patent-Law do not deny; but
they attribute them to the defective execution of the law, not to its
vicious principle. Hence a never-ending cry, as in the case of all bad
laws, for more legislation, for more stringent regulation, for stricter
investigation, and more thorough registration of Patents. But no
tinkering at details can avail. The whole system is radically unsound;
and the only effectual remedy is to lay the axe to the root.
A sentimental plea in favour of Patent-right has been set up by
some, on the ground that the inventor—the man of thought, as he is
called—must be saved from the toils of the capitalist, ever ready to
prey on his superior intellect. This silly sentimentalism could only
originate in an utter ignorance of the relations which naturally subsist
between capital and talent. The capitalist is the natural ally of the
inventor, whom it is his interest to employ and encourage. It is a chief
part of the business of every producer to search out every one who
can help him to improved methods of production; and the
remuneration which, in one shape or another, it is the interest of the
capitalist to offer to the really clever inventor, will always form a surer
and more substantial reward than the delusive privilege of a legal
monopoly. As to the complaints we hear of neglected talent, we may
safely conclude that they arise more from the exaggerated
pretensions of conceited schemers, than from any obtuseness to
their own interests on the part of practical men of business, who
refuse to profit by their inventions.
On the whole, Patent-Law seems a blunder, founded on the
antiquated notion of giving State encouragement to certain favoured
modes of human activity. It is no part of the duty of the State to
stimulate or reward invention; the true function of Government is to
protect, not to direct, the exercise of human energy. By securing
perfect freedom to each individual, we shall best provide for the
progress of the community; nor can any law be conceived more
detrimental to the common weal than one which lays restrictions on
perfect freedom of thought.
 ARE INVENTIONS PROPERTY?
BY M. T. N. BENARD,
Editor of the “Journal des Economistes,” July, 1868.
(Translated and Reprinted by his obliging consent.)
In the number of the Journal des Economistes for last December
there appeared a very conscientious paper on “Property in
Inventions,” by our learned colleague, M. le Hardy de Beaulieu. We
would have preferred that some master of the science had published
an answer to this article, which it seems to us is based on a wrong
principle, and that he had given to the readers of this journal the
opposite view of those ideas so ably set forth by the honourable
Professor of Political Economy at the Belgian “Musée de l’Industrie.”
We believe that this question has acquired sufficient importance
and reality to merit being fully argued and cleared up; and, no other
having taken up the pen in answer, we shall endeavour to set forth
the principle which alone appears to us true and admittable.
We throw out these ideas for discussion, hoping that the subject
will be taken up by one of our masters in the science, and that this
great debate will be carried out in a manner suitable to the
imperishable doctrines of justice and equity, which form the basis of
political economy.

I.
“The man who first made a hut,” says M. le Hardy de Beaulieu, “a
piece of furniture, a cloak, or some necessary of life, would no doubt
have thereby excited the envy of his neighbours, and he would
frequently have been deprived of these objects by violence or by
strategy, before it would be generally allowed that they ought to
belong to him who made them, and that it was at once the duty and
the interest of the community to guarantee him their possession
against every attack.”
We acknowledge that the man who first constructed a hut was
perfectly right in making good his claim against those who would
have deprived him of it, and that he was justified in vindicating his
claim by force. He had employed his time and strength in building
this hut; it was undoubtedly his, and his neighbours acted up to their
natural right and in their own interests in helping him to oppose the
intruder. But there ended both the right of the individual and that of
the community.
If this first man, not content with claiming his hut, had pretended
that the idea of building it belonged exclusively to him, and that
consequently no other human being had a right to build a similar
one, the neighbours would have revolted against so monstrous a
pretension, and would never have allowed so mischievous an
extension of the right which he had in the produce of his labour.
Nevertheless, this man had exercised imagination and
combination; he had invented the shape, the size, and the
arrangement of the whole structure; he was the first to conceive—
probably after many efforts of mind and thought, after long study,
after observations made on the nests of birds and the hut of the
beaver—that pile of branches, of dead wood, of leaves and of
stones, of which its shelter is formed. He was an inventor of the first
class. How is it, then, that the sentiment of justice which prompted
him to claim his property did not prompt him at the same time to
claim exclusive possession in the idea, the result of a long train of
reflection? How is it that the same sentiment of justice which induced
his neighbours, the community, to lend him armed force to preserve
for him the possession of his hut, did not go so far as to grant him a
property in his idea? No one dreamed of asking him for the
permission to imitate what he had made; no one thought he was
committing a crime, or doing him a wrong, in making a copy of his
hut.
Property can be a right only when its principles tend to the general
good and are useful in advancing the interests of the human race.
And if, in our day, imitation of an invention is not generally
considered as guilty an act as robbery of tangible property, it is
because every one understands the difference between an idea and
a thing made or done.
The inventor of a particular weapon, or certain furnishings, or
tools, had all possible rights in the constructing and possession of
these weapons, furnishings, or tools; but these rights could not be
extended to the hindering of his neighbours from making tools,
furnishings, or weapons, in every way similar. If the community had
admitted an exclusive right in these inventions, it would have died in
its germ, civilization would have been a dead letter, and man would
have been unable to fulfil his destiny.
Thus far, then, there was not, nor could be in principle, any
question of exclusive right of invention. This right was only thought of
when all notions of social right had been obscured by laws which,
like that of Henry II., declared that the right of labour belonged to the
Crown, and when there had grown up the idea of licensing labour
and granting exclusive privileges for its exercise. The institution of
the pretended property in inventions was a retaliation against the
suppression of the abusive right of masterships and corporations.

II.
Doubtless invention, as M. le Hardy de Beaulieu remarks, consists
in the discovery of a new scientific principle; but we cannot admit,
with the learned Professor, that the new application of a principle
already known, that the discovery of a natural agent hitherto
unknown, or of new properties or other modes of action of natural
agents, or of materials previously discovered, are inventions.
It is probable that coal was known long before any one thought of
putting it in a stove to be used as fuel. It is certain that stone was
known long before any one thought of employing it in the
construction of walls.
To pretend that the discovery of the combustible quality of coal, or
of the use to which stone might be put, gave a right to the discoverer
to exact from his neighbours the payment of a royalty before
employing this fuel, or this material for construction, is also to grant
that he who, centuries before, had thought of burning wood to warm
himself, or of seeking the shelter of a cave, ought also to be
recompensed for the trouble he had in discovering, appropriating,
and working out either this source of heat or this means of shelter.
Invention, we acknowledge, consists in the discovery of a new
scientific principle; it can often place, as M. le Hardy de Beaulieu
says, new gratuitous forces at the disposal of the community; but
does it follow that the inventor has an exclusive right in the property
of this discovery? We think not. The inventor of the compass,
whoever he was, has rendered an immense service to the
community; but could his invention be claimed as private property?
Does it not, on the contrary, enter with perfect justice into the public
domain?
Napier, the discoverer of logarithms, has rendered the most signal
service to calculators and navigators; but can his invention, the
knowledge of which may, either orally or by the printing-press, be
extended indefinitely—which any one may use privately, in the quiet
of the study—be put upon the same footing as landed property,
which a single man may cultivate—as house property, which may
belong to one or several, and which cannot be seized upon without
its being observed, and to the great scandal of all? Evidently not.
And if the law has never tried to appropriate inventions of this
class, it is because there must be something tangible, limited, and
final, giving the power to regulate its employment or possession.
It is not correct to say, besides, that the inventor does not deprive
the community of any portion of the common property which it
possessed before the invention. Before the invention the thing
discovered existed in embryo—in nature. This germ was multiple; it
existed as frequently as there were men; and the inventor pretends,
by the property in it which he claims, to deny it to all others and to
hinder its germination.
The right of the inventor is limited to that of working out his idea; it
is identical with that of a man who has discovered and cleared a
field; but it is not, like his, exclusive. He who invents and he who
clears can possess their property as long as they like and as they
like; but there is this difference between the field and the invention:
the first can be cultivated only by one without doing an injury to the
proprietor, while the invention may be used by several without
hindering, diminishing, or suppressing the working of it by the
inventor.
I have cleared a field, and cultivate it; if one of my neighbours
desires also to cultivate the same field, he hinders me from
exercising my right—he interferes with my working—he
dispossesses me.
I have discovered the combustible nature of coal: in what way
does my neighbour, who cooks his food on a coal fire, hinder me
from exercising my right, or interfere with the working of my
faculties? of what does he dispossess me?

III.
We have not, as we think, to take into consideration more or less
the difficulties of inventors; we have not to inquire if every invention
requires a more than ordinary degree of intelligence, special
knowledge, great perseverance, &c. There is a multitude of
occupations in life which require all these qualities, but no one has
ever pretended that on account of these qualities, probable sources
of success for them, they had a right to any favours, immunities, or
privileges.
The inventor of a useful discovery has quite as much, or more,
chance of making a fortune as the manufacturer who confines
himself to the beaten tracks, and only employs the known methods;
this last has had quite as much risk of being ruined as any searcher
after discovery. We believe that they are on an equality as to
position; for if the inventor may be ruined in not finding what he
seeks, the manufacturer may see all his looms or his machines
rendered useless, all his outlets closed, by the introduction of a
cheaper means of production. Why make a golden bridge for him
who enters the arena with arms more subtle and more finely
tempered than those of his adversary?
Notice that the manufacturer also renders a service to the
community—no doubt in seeking his own profit; but is it not so with
the inventor? Why then demand a reward for the one which is not
asked for the other?
The manufacturer who, in using the old looms, manages his
factory so as to reduce his prices by 10 or 20 per cent., and who in
consequence can furnish stockings (supposing him to be a stocking
manufacturer) to a number of those who were not rich enough to buy
them at the old prices, undoubtedly does a service to the community
equal to that which it would receive from the invention of a machine
which would make the stockings 10 or 20 per cent. cheaper.
The farmer who by superior ploughing, more skilful manuring, or
more careful weeding, increases the yield from two to three quarters
per acre—does not he also render a signal service to the
community?
The sailor, who finds the means of shortening voyages by utilising
certain currents or winds, in modifying the spread of his sails, &c.—
does not he increase the gratuitous natural forces placed at the
disposal of the community?
Why, then, if there is question of rewarding this class of services,
should they not ask for privileges, favours, and exclusive rights?
Why not go so far as forbid any one to arrange his factory on the
plan of the manufacturers of whom we have been speaking? Why
not forbid any farmer to weed, plough, or manure, like his neighbour;
or any sailor to follow the track of the first, without paying to those
who gave the example a previous and perpetual royalty?

IV.
“The property of an invention having required for its creation the
same labour as that of the soil, and this work offering less chance of
success and results of probable less duration, it is as legitimate at
least as landed property,” says M. le Hardy de Beaulieu; “and there
is no argument against it which may not be applied with equal force
to the individual and permanent occupation of the soil.”
The soil, to render all the productions that the community has a
right to expect from it, ought to become and remain a personal
individual property. Invention, on the other hand, cannot give all the
results that society can draw from it, unless it be public property.
Herein lies the immense and irreconcilable difference between
property in land and that of invention. Besides, land cannot become
unfertile, unproductive, or lose all its value as property, except by
some convulsion of nature which would deeply unsettle it. An
invention, on the contrary, may become quite valueless in ten years,
one year, a fortnight even, after being discovered, and that by the
superiority of a subsequent invention.
What becomes, then, of the property of this invention? What is its
worth? Has the inventor a right to damages?
If you construct near my field a factory from which escape noxious
vapours, hurtful to vegetation, and if I can show that you have
deteriorated or destroyed my crops, you, according to the laws of
every civilised nation, owe me damages; would you claim damages
of the inventor, whose discovery had rendered that of one of his
predecessors partially or completely unproductive? If property in
invention is equal to property in the soil, damages are incontestably
due. We do not think that a single advocate for this class of property
has, however, dared to carry his logic thus far.
The proprietor of a field may leave it uncultivated, the proprietor of
a house may leave it shut up as long as he likes; no law obliges to
put in a tenant, or to open it for lodgers. The laws of all countries
contain, with slight modifications, the following clause, quoted from
Art. 32 of the Law of 1844:—“Will be deprived of all his rights ... the
patentee who shall not have commenced the working of his
discovery or invention in France within two years, dating from the
day of the signature of the Patent, or who shall have ceased working
it during two consecutive years, unless that, in one or other case, he
can satisfactorily explain the causes of his inaction.”
 It would be very easy for us to cite other differences in the nature
of these two classes of property; we shall only refer to one more,
which points out how solid is the property in land, and how uncertain
and ephemeral the so-called property of invention. Land, considered
as property, increases in value from day to day; there is no invention
whose value does not diminish daily.
M. le Hardy de Beaulieu further adds, that “the inventor, in taking
exclusive possession of his idea, harms no one, since he leaves all
which previously existed in the same condition in which he found it,
without in any way lessening the social capital on which he drew.”
We should require, however, to come to an understanding as to what
may be called the social capital; for if the exclusive property of
invention had existed from the germination of the idea which led to
the construction of the first hut to the making of the earliest weapons,
tools, and furniture, it is difficult to know where we should find it. By
putting property in invention on the same footing as property in the
soil, all that man uses or consumes would belong to the descendants
of the first inventors, and every one would require to pay a sort of
rent for its use. The inventor of the wheelbarrow would have to pay a
royalty to the inventor of wheels, and the maker of the plainest pump
would pay an annual rent to the inventor of the lever or piston; there
would not, there could not, be any social capital.
But it is wrong to say that the exclusive possession of an idea
hurts no one, because it leaves what previously existed in the same
condition. I, or my neighbour, might put together ideas to form the
basis of an invention; this faculty of combination belongs to each of
us; with exclusive possession it belongs only to one. It cannot be
said, then, that no one is hurt, and that everything remains in the
same position.
After having said that the property of invention is in every respect
similar to property in the soil, M. le Hardy de Beaulieu places,
nevertheless, boundaries to the extent and duration of the first. He
says: “It is not meant precisely that property in an invention ought to
extend over the globe, nor that its duration should have no limit in
time; all property, in fact, is bounded by the cost of preservation,
maintenance, and working, which it requires, already, long before the