退火温度对冷轧 Ti-13V-3Al-0.5Cu 形状记忆合金组织结构与马氏体相变的影响

The effect of post annealing temperature on the microstructure, martensitic transformation behavior, mechanical properties and shape memory effect of the cold rolled Ti-13V-3Al-0.5Cu (%, atomic fraction) alloy was systematically studied by means of XRD, TEM, DSC and tensile test at room temperature. The results showed that the phase composition of the alloy at room temperature was mainly α " phase, together with a small amount of remained β phase, α phase and Ti₂Cu second phase. With the increasing annealing temperature, the shape memory property increased firstly and then decreased. When the annealing temperature is 750℃, the alloy showed a good shape memory effect and the recoverable strain up to 5.3% when the pre-strain was 6%. Furthermore, the morphology of martensite transformed from a V-shape like self-coordinated-structure to a structure of single preferential orientation when the alloy was subjected to a proper cold rolling and annealing treatment. Lower reorientation critical stress and better interface mobility were the main causes for the improvement of shape memory effect.