形状记忆合金相变应变的取向关系及其织构控制原理

Orientation Dependence of the Transformation Strain and Its Texture Control in Shape Memory Alloy

形状记忆效应是基于马氏体相变及其逆转变,相变时母相与马氏体相之间存在严格的晶体学取向关系。根据唯象理论,相变织构是可以预估的。同样地对于相变应变也存在取向关系,通过多晶材料的织构分析也可以预估。铜基形状记忆合金沿<100>方向呈最大的相变延伸,通过适当的热机械处理可以获得沿同轧向成45°方向的最大强度的<100>织构取向分量,因而有最佳的记忆效应。

Shape memory effect is based on martensitic transformation and its reverse transformation. These effects are crystallographically strictly oriented. The shape memory effects may be calculated either from the shape strain calculated using the phenomenological theory or from the lattice deformation matrix. In duplex Cu-Zn-Al memory alloy, the trausformation strain can be controlled by texture which was obtained by using subsequently thermo-mechanical processing and betatizing treatment.