Comparison of Bond Order, Metal d Orbital Energy Level, Mechanical and Shape Memory Properties of Ti–Cr–Sn and Ti–Ag–Sn Alloys

Abstract

Bond order (B 0 ) and metal d orbital energy level (M d ) values were calculated for our recently developed Ti(6,7)Cr3Sn and Cr substituted Ti(6,7)Ag3Sn alloys developed in this study. Position of these alloys in the B 0 -M d phase stability map developed by Morinaga and co-workers was then determined. Phase constitution, mechanical and shape memory properties were co-related with the position of Ti(6,7)Cr3Sn and Cr substituted Ti(6,7)Ag3Sn alloy in the B 0 -M d phase stability map. Cr substitution with Ag has resulted drastic decrease in the bond order (B 0 ) and metal d orbital energy level (M d ) values, resulting drastic decrease in the strength, fracture strain and shape memory properties. Position of Ti(6,7)Cr3Sn alloys was within the twinning region of B 0 -M d phase stability map and these alloys exhibited good mechanical and shape memory properties due to stress induced martensitic transformation. It is concluded that position of developed TiCrSn and TiAgSn alloys in the B 0 -M d phase stability map not only affect the phase constitution but also the mechanical and shape memory properties.

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Brief Overview on Nitinol as Biomaterial

“…The current author's Ph.D. thesis work, completed in 2012 from Hosoda-Inamura Lab, Tokyo Institute of Technology, Japan, was related to nickel-free titanium based shape memory alloys for biomedical applications [77]. The current author has published a number of papers related to nickel-free titanium based shape memory alloys for biomedical and engineering applications in international journals [78][79][80][81][82][83][84][85][86]. During postdoctoral work from 2012 to 2014 in the High Temperature Materials Unit, National Institute for Materials Science (NIMS), Tsukuba, Japan, the current author's research activities were related to TiPt and TiAu based intermetallics for high temperature applications and he has published papers in international journals [87][88][89][90][91][92][93][94].…”

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