Ti-Ni-Nb宽滞后形状记忆合金的应力诱发马氏体相变行为

用在（Ms＋30℃）温度下的拉伸实验和差示扫描量热仪（DSC）较系统地研究了Ti44Ni47Nb9宽滞后形状记忆合金应力诱发马氏体的相变行为。研究结果表明：当形变量达到14％左右时，应力诱发马氏体相变过程基本完成。应力诱发马氏体的逆相变温度间隔要比热诱发马氏体约小一个数量级。形变对该合金应力诱发马氏体的逆转变开始温度、逆转变温度间隔以及相变潜热均有明显影响，随着拉伸变形量的增加而增加。而在随后的冷却循环中，相变潜热和马氏体相变开始温度均随着形变的增加缓慢降低。

Deformation Dependence of Transformation Behavior of Ti-Ni-Nb Wide Hysteresis Shape Memory Alloy

This work is to systemically study the effect of deformation on the stress-induced martensitic transformation behavior of Ti44Ni47Nb9 alloy by performing differential scanning calorimetry (DSC) and cryogenic tensile tests at a temperature of (Ms+30℃). DSC measurements showed that the process of stress-induced martensitic transformation had been completed as the specimen was deformed to about 14% of strain in tension. The reverse transformation temperature interval of the stress-induced martensite is much smaller than that of the thermally induced martensite. The experimental results also indicated that As temperature of the reverse transformation, the reverse transformation temperature interval and the transformation heat of the deformed specimen associated with the stress-induced martensite are increased with increasing of the level of deformation. However, the wide hysteresis effect due to the deformation vanished after heating. The transformation heat and the forward transformation start temperature of the subsequent cooling are decreased slightly with increasing of strain.