不锈铁基形状记忆合金记忆机制的研究

Mechanism of Shape Memory in Stainless Iron-Based Shape Memory Alloy

本文利用拉伸变形、ｘ射线衍射、光学金相和透射电子显微镜等测试方法研究了不锈铁基形状记忆合金Ｆｅ－Ｃｒ－Ｎｉ－Ｍｎ－Ｓｉ的微现行为。试验结果表明，室温拉伸变形量较小（在２％以内）时，可获得较完全的形状记忆效应，这主要与形变过程中产生单一位向的ε马氏体和大量单一位向的形变孪晶在加热时的逆转变相联系。当形变量较大（大于３％）时，形状记忆效应迅速降低，这与形变过程中产生不同位向的ε马氏体和形变孪晶以及滑移产生不可逆塑性变形和形成多量的α￣′马氏体有关。

The microscopic behavier has been in-vestigated in stainless iron─based shape memoryalloy(SMA ) Fe-Cr-Ni-Mn-Si by means of tensiledeformation,x-ray diffraction,optical metallo-scope and transmission electron microscope。 Theexperiment results show that the more completshape memory effect(SME)can be obtained whenthe tensile deformation is smaller(within2%)atroomtemperature. This is connected with producingone orientational εmartensite and deformation twinduring deformation as well as thir reversible transformation in heating. As the deformation is bigger(above 3%) ,the SME is decreased speedily.Andthathas relation to producing nonreversible slip de-formation and a great deal of α′martensite.