The Effect of Vacancy on The Phase Stability of TiNi Shape Memory Alloy from First-Principle Calculation
The effect of vacancy on the phase stability of TiNi shape memory alloy has been investigated by the first-principle method based on the density functional theory with generalized gradient approximation. The formation energy, formation heat, formation enthalpy per atom and density of states (DOS) of TiNi alloy with and without vacancy are calculated. The results indicate that the favorable point defect is Ni vacancy in both B2 and B19’ phases of TiNi alloy. The existence of vacancy increases the formation enthalpies per atom difference and thus decreases the phase stability. The DOS values at Fermi level of martensitic phases are lower than that of austenite phases in both perfect TiNi and TiNi with Ni vacancy, indicating the natural transformation from austenite to martensite upon cooling.
TiNi shape memory alloy first-principle calculation vacancy phase stability
Bin Yue Yan Li Fei Zhang
School of Materials Science and Engineering, Beihang University, Beijing 100191, China Key Laborator School of Materials Science and Engineering, Beihang University, Beijing 100191, China Key Laborator
国际会议
11th IUMRS International Conference in Asia(第十一届国际材联亚洲材料大会 IUMRS-ICA 2010)
青岛
英文
528-532
2010-09-25（万方平台首次上网日期，不代表论文的发表时间）