Site preference and phase stability of Ti doping Ni–Mn–Ga shape memory alloys from first-principles calculations
Site preference and phase stability of Ti doping Ni–Mn–Ga shape memory alloys from first-principles calculations
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DOI：
10.1016/j.jallcom.2013.05.193
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发表时间：
2013-10
影响因子：
6.2
通讯作者：
Zhiyong Gao;Baishu Chen;Xianglong Meng;W. Cai
中科院分区：
文献类型：
--
作者：
Zhiyong Gao;Baishu Chen;Xianglong Meng;W. Cai
采用基于密度泛函理论的第一性原理计算方法研究了Ti含量对Ni 50 Mn 25 Ga 25 − xTix形状记忆合金马氏体相变和相稳定性的影响.形成能的结果表明，添加的Ti优先占据Ga位在Ni 2 MnGa合金由于最低的形成能。奥氏体和马氏体之间的总能量差随Ti合金化而增加，这与实验报告的马氏体相变温度的变化有关。随着Ti含量的增加，Ni 50 Mn 25 Ga 25 − xTi x奥氏体的相稳定性降低，这是由于Ti取代Ga时Ni 3d-Mn 3d杂化减少所致。
The effects of Ti content on martensitic transformation and phase stability of Ni50Mn25Ga25−xTixshape memory alloys were investigated from first-principles calculations based on density functional theory. The formation energy results indicate that the added Ti preferentially occupies the Ga sites in Ni2MnGa alloy due to the lowest formation energy. The total energy difference between austenite and martensite increases with Ti alloying, being relevant to the experimentally reported changes in martensitic transformation temperature. The phase stability of Ni50Mn25Ga25−xTixaustenite decreases with increasing Ti content, which results from the reduced Ni 3d–Mn 3d hybridization when Ga is replaced by Ti.