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采用拉伸试验、电阻测量、电镜观察等方法对49.5Ti-40.5Ni-10Cu(at％)合金的超弹性特征以及在马氏体状态下的形变处理对该特性的影响进行了研究、实验结果表明;合金经1123K、0.5hr空冷处理后在308K—323K温度区间表现出完全超弹性、可逆应变值4％、其超弹性滞回曲线的特征随反复加载—卸载循环而发生明显变化。通过在低温状态对合金施加一定的形变量并随即在再结晶温度以下进行退火处理,可使合金呈现超弹性的温度区间向高温方向移动、增加可逆应变量以及使超弹性滞回曲线保持稳定。形变处理后合金相变温度升高、母相屈服强度增加以及处理后的位错组态对马氏体相变的影响是导致上述变化的主要原因。
The superelastic properties of 49.5Ti-40.5Ni-10Cu (at%) alloy and the effect of deformation treatment in the martensitic state on this property were investigated by means of tensile test, electrical resistance measurement and electron microscope observation. The experimental results The results show that the superelastic hysteresis curve of the alloy shows completely hyperelasticity and reversible strain value of 4% at the temperature of 308K-323K after air-cooling at 1123K and 0.5hr. The characteristics of the hyperelastic hysteresis curve change obviously with repeated loading-unloading cycles. By applying a certain amount of deformation to the alloy at a low temperature and then annealing below the recrystallization temperature, the hyperthermoplastic temperature range of the alloy can be shifted in the high temperature direction, increasing the amount of reversible strain and stabilizing the hyperelastic hysteresis curve. After deformation treatment, the phase transformation temperature of the alloy increases, the increase of the matrix yield strength and the dislocation configuration after treatment affect the martensitic transformation, which is the main reason for the above changes.