INTRODUCTION TO ADDITIVE

MANUFACTURING (AM) ?
What is additive manufacturing?
Additive manufacturing is the process of creating an object
by building it one layer at a time. It is the opposite of
subtractive manufacturing, in which an object is created by
cutting away at a solid block of material until the final
product is complete. It transforms a CAD model into a real
object by layer to layer deposition of materials.
The term "3D printing“ or ‘’Rapid Prototyping” is increasingly
used as for Additive manufacturing.
 INTRODUCTION TO ADDITIVE
MANUFACTURING (AM) ?
 The process is ‘additive’ in nature, with layers being successively added to
build a part, as opposed to ‘subtractive’ technologies, where material is
removed or shaped by machining, milling or forming. Importantly.
 In Additive Manufacturing the part geometry is always digitally defined and
based on digital 3D model data from a computer-aided design (CAD)
program.
 Additive Manufacturing offers many advantages over more traditional
manufacturing technologies. The ability to selectively deposit materials only
where they are needed means that parts can be much more complex in
design, and lighter weight, which can dramatically improve performance.
The process is tool less, unlike processes such as casting and injection
molding that require significant up-front investment in tooling, and offers
increased design freedom as well as one-off or personalized products. The
tool less nature of the process meant that prototypes could be fabricated
easily and checked for form, fit and function, enabling rapid innovation in
product development.
.
 INTRODUCTION TO ADDITIVE
MANUFACTURING (AM) ?
 After all, the actual build is only one part of a much larger
process. In this article, we'll look at the entire additive
manufacturing process from start to finish.

The steps involved in Additive Manufacturing Process



 Step 1: Using CAD Software to Design a Model. ...

 Step 2: Pre-Processing. ...

 Step 3: Printing. ...

 Step 4: Post-processing.
Subtractive manufacturing Additive manufacturing
•3D objects are constructed by •Here 3D objects are created by
successively cutting material away successively depositing material in
from a solid block of material layers 

•Wastage produced is more • No wastage

• Conventional machining like • New class of machining
turning, milling, drilling etc.
• Less finishing required • Finishing required is more
• More initial cost & energy • Less initial cost & energy
consumption consumption
INTRODUCTION TO ADDITIVE
MANUFACTURING (AM)
INTRODUCTION TO ADDITIVE
MANUFACTURING (AM)
INTRODUCTION TO ADDITIVE
MANUFACTURING (AM)
INTRODUCTION TO ADDITIVE
MANUFACTURING (AM)
BENIFITS OF AM TECHNOLOGY
INTRODUCTION TO ADDITIVE
MANUFACTURING (AM) ?
 BENIFITS OF AM TECHNOLOGY
 Increased design freedom versus conventional casting and machining.
 Light weight structures made possible either by the use of lattice design or
by designing parts where material is only where it needs to be, without
other constraints.
 New functions such as complex internal channels or parts built in one.
 Net less raw material consumption , up to 25 times less versus machining.
 LIMITATION OF AM TECHNOLOGY
 Part size : In the case of powder bed technology the powder is
limited to small size.
 Production size : It is suitable for small size not for mass
production.
 Material properties : The parts made by this additive manufacturing
tends to show anisotropy in the Z axis.
 Density of 99.9% can be reached but by there can be residual
internal porosity.
 CLASSIFICATION OF RP SYSTEMS
There are various ways by which RP technologies can be classified :
Based on the starting/input state:-
Liquid Based : SLA, DLP
 Stereo lithography (SLA)

 Digital Light Process (DLP)

Solid Based : Pellets, wires, Sheets, FDM, LOM, MJM

 Fused Deposition Modeling (FDM)

 Laminated Object Manufacturing (LOM)

 Multi Jet Modeling (MJM)

Powder based : SLS, 3DP, LENS, EBM, SLM, DLMS

 Selective Laser Sintering (SLS)

 Three Dimensional plasma

 Laser Engineered Net Shaping (LENS)

 Electron Beam Melting (EBM)

 Selective laser melting (SLM)

 Direct Metal Laser Sintering (DMLS)

Based on Dimensions of input material:-

 0 dimension : Powder based

 1 dimension : Wire/Filament based

 2 dimension : Sheet Based

Based on the output material:-

 Metal Based printers : SLM, DLMS, EBM

 Polymer Based Printers : FDM, SLA

(ABS, PA6, PLA, HDPE, LDPE)

 Ceramic Based Printers

Based upon the application :-

 Normal Printers : FDM, SLM, SLA,

 Office Modellers : MJP, GeneSys XS printers, Sanders Model

Makers, HP printers
Classification of Additive Manufacturing
 NEED FOR TIME COMPRESSION IN PRODUCT
DEVELOPMENT
 Engineering and product development is where innovative ideas begin.
Implementing the ideas becomes more of a challenge. With rapid
advancements in technology and high standards of the current business
climate, engineering professionals are facing compression more than ever. This
means they are squeezed in terms of time and money to get a product to
market. This blog discusses how communication helps manufacturing
companies handle compression.
 Engineering and product development is on the front end of the whole
manufacturing process. The development team must thoroughly understand the
voice of the customer so engineers come up with the effective, efficient
designs to maximize speed to market and customer performance. One
challenge facing most engineers today is compression. Product design
engineers are more and more constrained which means they have less time and
less budget to produce a more technologically-advanced product.
 NEED FOR TIME COMPRESSION IN PRODUCT
DEVELOPMENT

 When Implementation Engineers helps companies improve their design cycle,

initially, many client engineers and designers have good ideas about how to
improve manufacturing. However, part of the challenge is getting data back to
the source and feeding key learning's back into the group. Communication
across cross functional teams is vital to perfecting engineering innovations.
 With a higher volume of programs, companies want to design for
manufacturability with representation and coordination across groups so that
the manufacturing folks, who have a lot of good ideas, additionally are heard.
Many times, all the teams aren’t properly integrated within initial phases of
product design. This takes communicating with the engineering and product
development across channels.
 NEED FOR TIME COMPRESSION IN
PRODUCT DEVELOPMENT
What is purpose of time Compression?
 Time Compression provides the means to optimize the use of time in a
business and can motivate an organization towards competing in a changing
environment. WHAT IS STRATEGY? introduction to the idea of developing a
strategy and an explanation of how a focus on time can be used to deliver
competitive advantage.
 NEED FOR TIME COMPRESSION IN
PRODUCT DEVELOPMENT
Compression Challenges in Product Development ?
 Compression is the amount of time it takes to design a new product. With
compression, companies have rapid changes that require them to be more
flexible and effective in the engineering processes. With more compression,
companies want to make the right changes at the right time as quickly as
possible.
 Handle coordination across groups
 Increase visibility with the digital dashboard
 Understand why they have engineering changes
 Determine which changes they can bundle together to implement the change
 Conceptual Detail Engg.
Prototyping Tooling Production
design Design Analysis

CONVENTIONAL MANUFACTURING

CONCEPTUAL DESIGN
CAD MODELLING
DETAIL DESIGN

ENGINEERING
FEA
ANALYSIS TIME SAVE

PROTOTYPING

TOOLING
RP
PRODUCTION

MARKETING

TIME

FIGURE :- TIME COMPRESSION WITH THE HELP OF RP

ADDITIVE MANUFACTURING TECHNIQUES
Stereo Lithography Apparatus (SLA) Selective Laser Sintering (SLS)

Laminated Object Manufacturing (LOM) Fused Deposition Modelling (FDM)

Courtesy:- Mr. D. Chandramohan, Dr. K. Marimuthu, Rapid prototyping/rapid tooling – a over view
And its applications in orthopaedics, International Journal of Advanced Engineering Technology
 FDM AND SLS TECHNIQUE

 Fused Deposition Modelling

Principle

Operation

Construction

Materials

Process parameters

Advantages , Limitation and Applications

 FUSED DEPOSITION MODELLING (FDM)
 FDM works on an "additive" principle by laying down material in
layers. A plastic filament or metal wire is unwound from a coil and
supplies material to an extrusion nozzle which can turn the flow on and
off.
 The 3D printers that work on FDM technology consist of the printer
platform, a nozzle (also called as printer head) and the raw material in
the form of a filament.
 The Printer Platform
The printer platform or the bed is typically made of some metal, ceramic
or hard plastic, and each successive layer is deposited on this platform. 
 The Nozzle / Printer Head

The nozzle of FDM printers is attached to a mechanical chassis which uses

belt and / or lead screw systems to move it. The entire extrusion
assembly is allowed to move in X, Y and Z dimensions by a motorized
system. A fourth motor called as the stepper motor is used to advance
the thermoplastic material into the nozzle. All the movements of the
head and the raw material are controlled by a computer.
 MATERIALS
 Most popular material is ABS. ABS stands for
Acrylonitrile Butadiene Styrene.

 ULTEM material –Stratasys

 Second most popular material is PLA. PLA stands for

Poly Lactic Acid. Biodegradable. Made from sugarcane.

 Nylon (PA6) is also becoming famous now

 HIPS, PETG, HDPE, LDPE can also be used

 FUSED DEPOSITION MODELLING (FDM)
 The raw material is typically production grade thermoplastics, though
sometimes metal is used as well. The thermoplastic material is capable
of being repeatedly melted when exposed to heat and re-solidified when
the heat is withdrawn. The thermoplastic filament or metal wire is
wound as a coil on a mounted spool. It is then fed through the printer
nozzle. The better class of 3D FDM printers allows the temperature of
the nozzle to be maintained just close to the glass transition temperature
of the material being extruded. This allows the material to be extruded
in a semi-liquid state, but return to solid state immediately. This results
in a better dimensional accuracy.
 In principle, any thermoplastic can be used as raw material for FDM
printers. Commercially, a few of the popular choices of raw material
include nylon, Acrylonitrile Butadiene Styrene (ABS) and its
variations, polycarbonates, ply-lactic acid, polystyrene and
thermoplastic urethane.
 FUSED DEPOSITION MODELLING (FDM)
 The FDM 3D Printing Process :

When the FDM printer begins printing, the raw material is extruded as a
thin filament through the heated nozzle. It is deposited at the bottom of
the printer platform, where it solidifies. The next layer that is extruded
fuses with the layer below, building the object from the bottom up layer
by layer. 
Most FDM printers first print the outer edges, the interior edges next
and lastly the interior of the layer as either a solid layer or as a fill in
matrix.
 In some objects / models, there are fragile ‘overhangs’ that will droop
unless they are given some support. FDM printers incorporate a
mechanism whereby these support structures (called struts) are printed
along with the object. They are later removed once the build is
complete.
FUSED DEPOSITION MODELLING (FDM)

Icing on a cake

Courtesy:- Mr. D. Chandramohan, Dr. K. Marimuthu, Rapid prototyping/rapid tooling – a over view
And its applications in orthopaedics, International Journal of Advanced Engineering Technology
 PEEK is becoming very famous nowadays for medical
applications

 FDM works best with polymers that are Amorphous in

nature as compared to crystalline polymers.

 Not all polymers are FDM printable.

 Materials are ABS, PLA, PETG, HIPS, LDPE, Nylon and

PEEK.

 Virgin polymers-------Composite polymers-------Metal

reinforced composite polymers
 MATERIALS FOR FDM PRINTING

Materials/ ABS PLA HIPS PA6 PETG PEEK

Properties (Nylon)
Tensile Strength 34 65 22 42.2 55.5 100
(Mpa)
Tg (0C) 110 60 89 47 80 143
Tm (0C) 130 170 180 215 250 343
Bio-degradable No Yes No No No No

Soluble in Acetone Ethyll- Di- NA NA NA

acetate Lemonine
5) SPEED, BED TEMPERATURE AND NOZZLE
TEMPERATURES

 Speed usually set is 60 mm/sec

 Bed Temperature set is 110 degree Celsius

 Nozzle temperature set is 220 degree Celsius

PROCESS PARAMETERS
1) Layer Thickness
•This setting controls the height of the slices.
• It has been established by numerous researchers that layer
thickness does affect the surface finish of the parts produced
Layer
Thickness

•L.T increases Surface Roughness Increase

•L.T. Increases Total Build time Decreases
2) Infill Percentages
•This setting controls the density of internal fills of the parts produced

Infill % increases Build Time increases

Infill % increases Strength increases

Infill

Straight pattern Orthogonal pattern Zig Zag pattern

3) SUPPORT STRUCTURES
OVERHANGING STRUCTURES REQUIRES SUPPORT STRUCTURES. GENERALLY
GREATER THAT 15 DEGREES PRINT WILL REQUIRE SUPPORT.

Support

Support can be:-

•Coarse
•Rough
•Medium
•Dense
•Fine
•Ultra
4) Part Orientation
ADVANTAGES AND LIMITATIONS OF
FDM
Advantages
 The process is clean, simple, easy to use and operate

 No wastage of materials
 Lack of expensive lenses, lasers as seen in Photo-polymerisation or
Sintering Techniques

Limitations
 FDM machines are costly
 Because of circular nozzles sharp edges cannot be made easily
 Low speed and accuracy
 Parts are An-Isotropy in nature (Z direction )
 Dimensional accuracy is bad
 Surface finish is bad
Rocket Engine Injector Manufactured with 3-D
Printing Machine by NASA

3D Printing Creates New Parts for Aircraft Engines

 APPLICATIONS OF FDM
 FDM 3D Printers find application in:
 Creating prototypes for Fit, Form and Function testing ,rapid tooling patterns
and mould inserts ,creating and testing any parts that work under thermal
loads ,production of precise and complex end-use parts e.g. jigs & fixtures.
Sectors which also includes
 Automotive
 Aerospace
 Manufacturing
 Industrial
 Medical
 Architecture
 Consumer Goods 
 Fashion
 Education & Research
 SELECTIVE LASER SINTERING (SLS)
PROCESS (DMLS) (PBF) (EBM)
 Selective Laser Sintering is an powder based RP technique which
directly creates a physical model out of a CAD model by sintering

 Developed by Dr. Joe Beaman and his student at the university of

Texas at Austin, USA. Commercialised by DTM corp.

 Principle - the principle on which SLS works is SINTERING.

 Sintering depends upon the free energy (G) of the metal powders

 Free energy (G) = Volume of powders (V)/ Surface area of

powders(A)

 As V decreases or A increases G decreases

 As G decreases, Sintering rate increases

 Hence smaller the particles, greater will be the sintering process.

• The apparatus consists of three tanks – feeder tank, build up tank and excess powder
take up tank.

•Thin layers of powders (0.075-0.1 mm thick) are spread across the build area using a
counter-rotating powder levelling roller.

•The part building process takes place inside an enclosed chamber filled with nitrogen gas
(prevents oxidation).

•The powder in the build platform is maintained at high temperature

(below the melting temperature)
 Infrared heaters are placed above the build platform to maintain the elevated
temperature

 This minimises the laser power requirement as well as warping

 Co2 laser is used

 A focussed CO2 laser beam is directed onto the powder bed and is moved using
galvanometers.

 Supporting powder remains loose and serves as support for subsequent layers.

 After completion a layer, the build platform is lowered by one layer thickness and
a new layer of powder is laid and levelled using the counter rotating roller.

 The beam scans the subsequent slice cross section.

 This process repeats until the complete part is built.

 About 70% compaction is achieved.

 https://formlabs.com/blog/what-is-selective-laser-
sintering/
Material used :

Polymers and Composites:- Polyamide (nylon), PEEK, Polysterene, PLA etc.

Metals and Composites :- Steel, Ti and alloys, Ni based alloys, aluminium alloys etc.

Ceramics and Composites :- Alumimum oxide and Titanium oxide

Fusion Mechanisms :

Solid State Sintering : The image above

Liquid phase sintering : Partial melting Ex:- Groundnuts and Jagery

Chemically induced binding : use of thermally active chemicals. Used for binding ceramics

Full melting : melting, PA6.

 Partial melting

Selective Laser Sintering, Selective Laser Melting, Direct Metal Laser Sintering,
Electron Beam Melting etc.. Are the other names for the same technology.
PROCESS PARAMETERS
In PBF, process parameters can be lumped into four categories:

(1) laser-related parameters (laser power, spot size, pulse duration,

pulse frequency, etc.)

(2) Scan related parameters (scan speed, scan spacing, and scan
pattern)

(3) Powder-related parameters (particle shape, size, and distribution,

powder bed density, layer thickness, material properties, etc.), and

(4) Temperature-related parameters (powder bed temperature, powder

feeder temperature, temperature uniformity, etc.).
PROCESS BENEFITS AND DRAWBACKS
 Wide range of materials

 Different type of metals can be processed

 No support structure required and post processing

 Accuracy and surface finish of powder-based AM

processes are typically inferior to liquid-based processes
(depends on powder size)

 More total time in construction

RESEARCH AT KLSGIT IN ADDITIVE MANUFACTURING

Procured under VTU research grant scheme 2013

 Build size: 230x270x200 mm
 Maximum print volume: 13.7 litre
 Positioning accuracy: 0.05 mm
 Min. layer thickness: 0.05 mm
 Weight: 32 kg
 Electrical connection: 100-240 V
 Material types: ABS, PLA (1.75mm
diameter)
 Extruder size: 0.35 mm
 Speed X and Y axis: Up to 0.35 m/s
 Extrusion speed: 200 mm/min
 Power consumption: 400 W
 Production speed: 2 cm3/min
 Dual extruder: ABS (model) & PLA
(support)
 Software: Repetier & Slicer
software’s
 HOW DOES A 3D PRINTER WORK?
https://www.youtube.com/watch?v=8EGjA-PAij4