超弹性镍钛形状记忆合金循环变形行为的研究进展

Research Progress in Cyclic Deformation of Super-Elastic NiTi Shape Memory Alloy

首先对近20年来在超弹性镍钛形状记忆合金循环变形行为研究方面的最新进展进行了简要的综述和评价,总结了超弹性镍钛形状记忆合金在应变控制和应力控制循环加载下的单轴循环变形特征,重点阐述了该合金在单轴循环变形过程中一些重要力学性能参数的变化规律、残余变形的发展和相变棘轮行为特征;然后,结合循环变形实验研究成果,在宏观唯象模型的框架下,介绍了近年来建立的3种典型的、超弹性镍钛形状记忆合金的循环本构模型,并评述了3种模型的预言能力;最后,讨论了已有研究在超弹性镍钛形状记忆合金热-机械耦合、非比例多轴循环变形行为以及循环变形微观机理研究方面存在的不足,并为相关问题的进一步研究提出了一些建议.

The research progresses in cyclic deformation of super-elastic NiTi alloy in the last two decades were reviewed,with an emphasis on the changes in some important mechanical parameters,the evolution of residual strains,and behaviors of transformation ratcheting.Three typical cyclic constitutive models of super-elastic NiTi alloy constructed based on the macroscopic phenomenological constitutive model,as well as their abilities to describe the cyclically accumulated residual strains and transformation ratcheting of the alloy,were outlined.Suggestions about the future work were presented to overcome the shortcomings in the existing researches,such as those in thermo-mechanical coupled cyclic deformation,non-proportional multiaxial cyclic deformation,and micro-mechanism of cyclic deformation.