TiNi和TiNiCu记忆合金薄膜的温度记忆效应研究

在形状记忆合金的相变过程中,如果温度升至TS后停止升温,并降温至马氏体相变结束温度Mf以下,则在下一次完全相变循环中出现动力学停顿,而这一动力学停止温度点与上次的停止温度密切相关,这一现象被称为温度记忆效应。该文通过示差扫描量热法对TiNi和TiNiCu合金薄膜进行一次或连续几次不完全相变,系统地研究了温度记忆效应。结果表明,不仅温度记忆效应是形状记忆合金固有现象,而且温度记忆效应与马氏体变体间的弹性能及母相和马氏体相之间的共格应变密切相关。

Study of Temperature Memory Effect in TiNi-Based Shape Memory Alloys Thin Films

If a reverse transformation of a shape memory alloy (SMA) is arrested at a temperature Ts between As and Af (As Ts Af) and cooled below Mf, a kinetic stop will appear in the next complete transformation cycle. The kinetic stop temperature is closely related to the previous arrested temperature. This phenomenon is named temperature memory effect (TME). In this work, the temperature memory effect in TiNi and TiNiCu thin films is systematically investigated by performing either a single incomplete cycle, or a sequence of incomplete cycles with different arrested temperatures. Results show that the TME is a common phenomenon in shape memory alloy, and is related to both the strain energy between martensites and coherent strain between parent phase and martensite.