温度循环对镍钛形状记忆合金超弹性和相变行为的影响

Effect of Temperature Cycling on Superelasticity and Phase Transformation Behavior of NiTi Shape Memory Alloy

通过拉伸试验和差示扫描量热法（DSC）等手段,研究了高温时效和高温、低温循环对镍钛形状记忆合金超弹性和相变行为的影响。结果表明,TNC1605镍钛合金在500℃时效后具有较高的上/下平台强度,并且具有较低的残余应变,马氏体逆相变终了温度Af约为22℃,具有较好的超弹性能。经过10次200℃高温保温4 h和液氮中保温4 h的高低温循环处理后,下平台强度、6%拉伸加载和卸载后残余应变、Af和超弹性性能参数保持稳定。

The effects of high temperature aging, high temperature and low temperature cycling on the superelasticity and phase transformation behavior of Ni Ti shape memory alloy were studied by means of tensile test and differential scanning calorimetry（DSC）. The results show that after aging at 500 ℃, TNC1605 Ni Ti shape memory alloy has higher upper/lower plateau strengths, and has low residual strain. Martensite reverse phase transition finish temperature Afis about 22 ℃, which has good superelastic property. After cycle treatment 10 times at 200 ℃ for 4 h and liquid nitrogen for 4 h, the lower strength,the residual strain at the 6% tensile loading and then unloading, Afand superelastic property parameters keep stable.