Twinned structure for shape memory: First-principles calculations
Twinned structure for shape memory: First-principles calculations
复制标题
DOI：
10.1103/physrevb.78.092103
复制
发表时间：
2008-09
影响因子：
3.7
通讯作者：
Xiao-Qian Wang
中科院分区：
文献类型：
--
作者：
Xiao-Qian Wang
我们对二元形状记忆合金NiTi， PdTi和PtTi的晶体结构以及从奥氏体到马氏体的转变进行了第一性原理计算。对转变路径的详细分析表明，立方$B2$和正交$B19$都演化为孪晶结构，然后转变为单斜$B1{9}^{\ensuremath{'}}$。与NiTi的低能体心正交结构相反，这种孪晶态的存在对于智能合金中形状记忆的存储至关重要。
We have performed first-principles calculations for the crystal structures of binary shape memory alloys NiTi, PdTi, and PtTi along with the transformation from austenite to martensite. A detailed analysis of the transition pathway shows that both the cubic $B2$ and the orthorhombic $B19$ evolve to a twinned structure followed by a transformation to the monoclinic $B1{9}^{\ensuremath{'}}$. In contrast to the low-energy body-centered orthorhombic structure for NiTi, the existence of this twinned state is essential for storing the shape memory in smart alloys.