Cr掺杂对Ti-Ni形状记忆合金相变和循环形变特性的影响  

EFFECT OF Cr ADDITION ON TRANSFORMATION AND CYCLIC DEFORMATION CHARACTERISTICS OF Ti-Ni SHAPE MEMORY ALLOY

作　　者：杨军[1] 贺志荣[1] 王芳[2] 王永善[1] 

机构地区：[1]陕西理工学院材料科学与工程学院,汉中723003 [2]陕西理工学院图书馆,汉中723003

出　　处：《金属学报》2011年第2期157-162,共6页Acta Metallurgica Sinica

基　　金：陕西省自然科学基金项目2009JM6010;陕西省教育厅科研计划项目09JK375资助~~

摘　　要：使用示差扫描量热仪(DSC)和拉伸实验研究了Cr掺杂对550℃退火态Ti-50.8Ni(原了分数,%)形状记忆合金相变和循环形变特性的影响.结果表明,Ti-50.8Ni合金冷却/加热时发生B2→R→M/M→B2型可逆相变,掺杂0.3%Cr后所得Ti-50.8Ni-0.3Cr合金的相变类型为B2→R→M/M→R→B2,相变温度大幅度降低.室温下,Ti-50.8Ni和Ti-50.8Ni0.3Cr合金的相组成均为母相B2,前者呈现形状记忆效应,后者呈现超弹性.随循环变形次数n的增加,Ti-50.8Ni合金的特性由形状记忆效应演变为线性超弹性,合金的应力诱发马氏体临界应力和积累残余应变迅速增加;Ti-50.8Ni-0.3Cr合金的特性由非完全超弹性演变为完全超弹性,超弹性应力-应变曲线形态比较稳定.随n增加,Ti-50.8Ni合金的超弹性残余应变ε_r减小,超弹性应变恢复率η_s增加;Ti-50.8Ni-0.3Cr合金的ε_r和η_s则分别稳定在较低和较高水平,超弹性稳定.The effect of Cr addition on the transformation and the cyclic deformation charac- teristics in 550℃ annealed Ti-50.8Ni shape memory alloy （SMA） were investigated by differential scanning calorimetry （DSC） and tensile test. The B2→R→M/M→B2 type reversiable transformation occurred in Ti-50.SNi alloy upon cooling/heating. After the addition of 0.3%Cr in Ti-50.8Ni alloy, the transformation type for Ti-50.SNi-0.3Cr alloy was B2→R→M/M→R→B2, and the transformation temperatures decreased significantly. At room temperature, the phase composition was parent phase B2 for both Ti 50.8Ni and Ti-50.SNi 0.3Cr alloys, while the former showed shape memory effect; the lat- ter showed superelasticity. With increasing cyclic deformation number n, Ti-50.SNi alloy evolved from shape memory effect to linear superelasticity, and its stress inducing martensitic critical stress and the accumulation residual strain increased rapidly; while Ti-50.SNi-0.3Cr alloy evolved from incomplete superelastic to complete superelastic, and the stress-strain curve shape was stable. With increasing n, the superelastic residual strain εr decreased and the superelastic strain recovery ratio rk of Ti-50.SNi alloyincreased, while the εr and ηs in Ti-50.8Ni-0.3Cr alloy kept at lower and higher values, respectively. The superelastic of Ti-50.8-0.3Cr alloy was stable.

关 键 词：TI-NI合金 Ti-Ni-Cr合金 形状记忆合金 相变 循环形变 

分 类 号：TG113.25[金属学及工艺—物理冶金]