An investigation was carried out to determine the effect of rapid solidification on the weld meta... more An investigation was carried out to determine the effect of rapid solidification on the weld metal microstructure of austenitic stainless steels and its implication on the ferrite constitution diagram. A wide variety of stainless steels were laser beam welded at different welding speeds and laser power levels. The results indicate that both weld pool cooling rate and the postsolidification solid-state
Two papers presented at the Sheffield International Symposium on Solidification are included. One... more Two papers presented at the Sheffield International Symposium on Solidification are included. One paper covers a theory to describe the relation between casting conditions and structure in directionally solidified peritectic alloys. Experiments on Pb-Bi and Sn-Cd alloys are used to check the theory. The second paper describes the application of a computer model of continuous casting to study the effects of ingot diameter and casting rate on heat flow and thermal stresses in an aluminum-magnesium alloy. (Author)
Description/Abstract The evolution of temperature and thermal stresses during friction stir weldi... more Description/Abstract The evolution of temperature and thermal stresses during friction stir welding of Al6061-T6 was investigated by means of in situ, time resolved neutron diffraction technique. A method was developed to deconvolute the temperature and stress from the ...
The specification discloses a corrosion-resistant intermetallic alloy comprising, in atomic perce... more The specification discloses a corrosion-resistant intermetallic alloy comprising, in atomic percent, an FeAl iron aluminide containing from about 30 to about 40% aluminum alloyed with from about 0.01 to 0.4% zirconium and from 0.01 to about 0.8% boron. The alloy exhibits considerably improved room temperature ductility for enhanced usefulness in structural applications. The high temperature strength and fabricability is improved
Welding behavior and welding metallurgy of several ordered intermetallic alloys are reviewed comp... more Welding behavior and welding metallurgy of several ordered intermetallic alloys are reviewed comprehensively. Weldability of these alloys has been found to be a strong function of composition, welding process and process parameters. Phase transformations associated with the weld thermal cycle play a critical role in determining the weldability of these alloys. Defect-free welds have been produced in several of these alloys. 31 refs., 11 figs., 3 tabs.
Processes for forming an enhanced material or structure are disclosed. The structure typically in... more Processes for forming an enhanced material or structure are disclosed. The structure typically includes a preform that has a first common surface and a recess below the first common surface. A filler is added to the recess and seams are friction stir welded, and materials may be stir mixed.
This invention is a process for joining metals to ceramics to form very strong bonds using low br... more This invention is a process for joining metals to ceramics to form very strong bonds using low brazing temperature, i.e., less than 750.degree. C., and particularly for joining nodular cast iron to partially stabilized zirconia. The process provides that the ceramic be coated with an active metal, such as titanium, that can form an intermetallic with a low melting point
Processes for friction stir welding, typically for comparatively thick plate materials using mult... more Processes for friction stir welding, typically for comparatively thick plate materials using multiple passes and multiple layers of a friction stir welding tool. In some embodiments a first portion of a fabrication preform and a second portion of the fabrication preform are placed adjacent to each other to form a joint, and there may be a groove adjacent the joint.
An investigation was carried out to determine the effect of rapid solidification on the weld meta... more An investigation was carried out to determine the effect of rapid solidification on the weld metal microstructure of austenitic stainless steels and its implication on the ferrite constitution diagram. A wide variety of stainless steels were laser beam welded at different welding speeds and laser power levels. The results indicate that both weld pool cooling rate and the postsolidification solid-state
Two papers presented at the Sheffield International Symposium on Solidification are included. One... more Two papers presented at the Sheffield International Symposium on Solidification are included. One paper covers a theory to describe the relation between casting conditions and structure in directionally solidified peritectic alloys. Experiments on Pb-Bi and Sn-Cd alloys are used to check the theory. The second paper describes the application of a computer model of continuous casting to study the effects of ingot diameter and casting rate on heat flow and thermal stresses in an aluminum-magnesium alloy. (Author)
Description/Abstract The evolution of temperature and thermal stresses during friction stir weldi... more Description/Abstract The evolution of temperature and thermal stresses during friction stir welding of Al6061-T6 was investigated by means of in situ, time resolved neutron diffraction technique. A method was developed to deconvolute the temperature and stress from the ...
The specification discloses a corrosion-resistant intermetallic alloy comprising, in atomic perce... more The specification discloses a corrosion-resistant intermetallic alloy comprising, in atomic percent, an FeAl iron aluminide containing from about 30 to about 40% aluminum alloyed with from about 0.01 to 0.4% zirconium and from 0.01 to about 0.8% boron. The alloy exhibits considerably improved room temperature ductility for enhanced usefulness in structural applications. The high temperature strength and fabricability is improved
Welding behavior and welding metallurgy of several ordered intermetallic alloys are reviewed comp... more Welding behavior and welding metallurgy of several ordered intermetallic alloys are reviewed comprehensively. Weldability of these alloys has been found to be a strong function of composition, welding process and process parameters. Phase transformations associated with the weld thermal cycle play a critical role in determining the weldability of these alloys. Defect-free welds have been produced in several of these alloys. 31 refs., 11 figs., 3 tabs.
Processes for forming an enhanced material or structure are disclosed. The structure typically in... more Processes for forming an enhanced material or structure are disclosed. The structure typically includes a preform that has a first common surface and a recess below the first common surface. A filler is added to the recess and seams are friction stir welded, and materials may be stir mixed.
This invention is a process for joining metals to ceramics to form very strong bonds using low br... more This invention is a process for joining metals to ceramics to form very strong bonds using low brazing temperature, i.e., less than 750.degree. C., and particularly for joining nodular cast iron to partially stabilized zirconia. The process provides that the ceramic be coated with an active metal, such as titanium, that can form an intermetallic with a low melting point
Processes for friction stir welding, typically for comparatively thick plate materials using mult... more Processes for friction stir welding, typically for comparatively thick plate materials using multiple passes and multiple layers of a friction stir welding tool. In some embodiments a first portion of a fabrication preform and a second portion of the fabrication preform are placed adjacent to each other to form a joint, and there may be a groove adjacent the joint.
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