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

抄録

Bond order (\overline{B₀}) and metal d orbital energy level (\overline{M_d}) values were calculated for our recently developed Ti–(6,7)Cr–3Sn and Cr substituted Ti–(6,7)Ag–3Sn alloys developed in this study. Position of these alloys in the \overline{B₀}-\overline{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)Cr–3Sn and Cr substituted Ti–(6,7)Ag–3Sn alloy in the \overline{B₀}-\overline{M_d} phase stability map. Cr substitution with Ag has resulted drastic decrease in the bond order (\overline{B₀}) and metal d orbital energy level (\overline{M_d}) values, resulting drastic decrease in the strength, fracture strain and shape memory properties. Position of Ti–(6,7)Cr–3Sn alloys was within the twinning region of \overline{B₀}-\overline{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 Ti–Cr–Sn and Ti–Ag–Sn alloys in the \overline{B₀}-\overline{M_d} phase stability map not only affect the phase constitution but also the mechanical and shape memory properties.