行为的影响
( 1. 西安交通大学润滑理论及轴承研究所， 西安 710049;
2. 西南交通大学 摩擦学研究所, 成都 610031)
摘 要: 考察了中温时效处理后的Ti-50.9%Ni（摩尔分数）合金在实验温度为20℃， 不同应变速率下的轴向压缩应力—应变力学行为。 实验结果表明： 随着应变速率的增加， 合金的应力诱发马氏体相变临界应力逐渐增加， 相变平台逐步消失， 卸载后的残余应变减小， 加载—卸载变形曲线的应力（应变）滞后也减小； 在较高加载速率下， 合金表现出类线性超弹性变形行为， 可获得高达4.5%的类线性超弹性。
关键字: 形状记忆合金； 相变； 超弹性； 应变速率； 应力—应变曲线
TiNi shape memory alloy under compression
（ 1. Theory of Lubrication and Bearing Research Institute,Xi′an Jiaotong University,
Xi′an 710049, China;
2. Tribology Research Institute, Southwest Jiaotong University, Chengdu 610031, China）
Abstract: The mechanical behavior of aged Ti-50.9%Ni(molar fraction) alloy under axial compression dynamic load was investigated under different strain rates at 20℃. The experimental results indicate that with the strain rate increasing, the critical stress for inducing martensitic transformation rises and the plateau of phase transformation disappears, while the stress (strain) hysteresis becomes smaller and the residual strain decreases. At higher strain rate, the alloy exhibits linear-like pseudoelasticity, which is up to 4.5%.
Key words: shape memory alloy; phase transformation; pseudoelasticity; strain rate; stress—strain curve
