1.7MeV电子辐照对TiNi形状记忆合金相变温度的影响

Effect of 1.7MeV Electron Irradiation on the Transformation Temperature of TiNi Shape Memory Alloys

用能量为 1.7MeV不同注量的电子辐照了 TiNi形状记忆合金，通过温度控制使辐照在合金的马氏体相进行，发现辐照使合金的马氏体逆相变开始温度 A s和结束温度 A f降低，且 A f对电子辐照更敏感，相变温度滞后宽度减小；马氏体相变开始温度 M s和结束温度 M f基本无变化。 XRD结果表明电子辐照造成了马氏体相点阵畸变，随辐照注量的增加有增大的趋势，并且较大注量的晶面间距都增大。说明辐照引入的点缺陷增加了马氏体弹性应变能使马氏体相稳定性降低，造成了马氏体逆相变温度的下降。

Specimens of shape memory TiNi alloys were irradiated with an energy of 1.7MeV electron over different dose.The transformation temperature was measured under similar conditions before and after electron irradiation by means of differential scanning catorimetry (DSC).The transformation temperature As of TiNi alloy was decreased from 329K for the virgin sample to 327K and Af from 358K to 351K when the dose was 1.58× 1021/m2,The hysteresis of martensitic transformation was decreased from 26K to 20K.But the Ms and Mf was only varied about 1K.The results of XRD show that the point- defects make the lattice distortion of martensite phase induced by electron irradiation.This is an indication that increasing the electron fluence enhances creation of defects and the production of lattice disorder by electron irradiation,and lowers the stabilization of martensite phase.