不同温度下钛镍形状记忆合金的超弹性特性

对国产TiNi形状记忆合金在不同温度下的准静态力学响应、特别是相变超弹性特性进行了试验研究．结果表明，TiNi合金在热弹性马氏体逆相变结束温度AF附近的一定温度范围内显示超弹性特征，且温度对其有显著影响．随着温度的升高，应力诱导热弹性马氏体的临界应力近似地呈线性增加趋势，但在AF附近发生间断性突降．试验结果还表明，随应力之增加，不可逆塑性变形在总变形中所占的比值逐渐增加，且这一比值随温度升高而增大；相应地，超弹性变形别逐渐减弱以至消失．

Study on Super-Elasticity of TiNi Shape-Memory-Alloy at Different Temperatures

The quasi-static mechanical response, particularly the phase-transformation super-elasticity, are investigated at different temperatures for the TiNi shape-memory alloy made in China. The experimental results show that in the temperatures around Ap, TiNi alloy displays notable super-elasticity, and upon which temperature has marked effects. With increase of temperature, the critical stress of stress-induced martensite transformation increases approximately linearly, and it displays discontinuance around the temperature AF. The experimental results also show that with the increase of both applied stress and temperature, the ratio of the irreversible plastic deformation in the total deformation increases gradually while the ratio of the reversible super-elastic deformation decreases and finally disappears.