(陕西理工大学 材料科学与工程学院，汉中 723001)
摘 要: 用拉伸实验研究经600 ℃时效1~50 h后，时效时间tag和应力-应变循环对Ti-50.8Ni-0.1Zr形状记忆合金超弹性(SE)的影响。结果表明：600 ℃时效处理后Ti-50.8Ni-0.1Zr合金具有较高的强度和良好的塑性。随tag延长，600 ℃时效态合金的抗拉强度Rm、断后伸长率A、应力诱发马氏体相变临界应力σM和能耗ΔW降低，残余应变εR先上升后下降。随着应力-应变循环次数增加，600 ℃时效1~50 h的合金由部分非线性超弹性逐渐转变为完全线性超弹性，ΔW和εR均逐渐降低并趋于稳定。要使600 ℃时效态Ti-50.8Ni-0.1Zr合金获得良好的SE特性，tag应小于20 h；要使该时效态合金获得稳定的SE特性，应对其进行不少于10次的预应力-应变循环。
关键字: Ti-Ni-Zr合金；时效时间；超弹性；应力-应变循环
（School of Materials Science and Engineering, Shaanxi University of Technology, Hanzhong 723001, China）
Abstract:The effects of aging time (tag) and stress-strain cycle on the superelasticity (SE) of Ti-50.8Ni-0.1Zr shape memory alloy aged at 600 ℃ for 1-50 h were investigated by the tensile test. The results show that the Ti-50.8Ni-0.1Zr alloy is of high strength and good ductility after aging treatment. The tensile strength Rm, percentage elongation A, critical stress σM for stress-induced martensite and energy dissipation ΔW of Ti-50.8Ni-0.1Zr alloy decrease gradually, while residual strain εR increases firstly and then decreases with increasing tag. With increasing stress-strain cycle number, the Ti-50.8Ni-0.1Zr alloy aged at 600 ℃ for 1-50 h transforms from incompletely nonlinear superelasticity to linear-like superelasticity, and the ΔW and εR of the alloy decrease gradually and tend to stability. In order to make 600 ℃ aged Ti-50.8Ni-0.1Zr alloy get excellent SE, the tag should be less than 20 h, and to make the alloy get stable SE, it should be subjected to a prestress-strain cycle of not less than 10 times.
Key words: Ti-Ni-Zr alloy; aging time; superelasticity; stress-strain cycling
