预变形对TiNiCr形状记忆合金超弹性及显微组织的影响

Effect of pre-deformation on superelasticity and microstructure of TiNiCr shape memory alloy

通过对TiNiCr形状记忆合金丝施加不同的预变形,利用拉伸实验和光学显微镜研究不同预变形对TiNiCr形状记忆合金超弹性和显微组织的影响。结果表明:预变形对TiNiCr形状记忆合金弹性有着显著的影响,TiNiCr合金弹性随着变形量的增加而增加,当变形量达到51.4%时,弹性的增加不明显,单纯的预变形不能使TiNiCr达到完全的非线性超弹性,但会使TiNiCr产生一种细小板条状且高度形变的马氏体变体;当变形量达到48.6%时,马氏体变体的体积明显增大,极大地提高了母相的强度,从而显著提高TiNiCr丝的弹性。

The effect of the different pre-deformation on superelasticity and microstructure of TiNiCr shape memory alloy was studied by means of tensile test and optical microscope. The results show that the effect of the pre-deformation on superelasticity is obvious. The superelasticity becomes better with the growing pre-deformation. When the deformation reaches 51.4%, the growing rate of superelasticity gets slow. The pre-deformation cannot make TiNiCr obtain complete non-linear superelasticity, but make a kind of fine and highly deformed martensite in TiNiCr. When the deformation reaches 48.6%, the martensite grows with the growing deformation, which increases the intensity of generatrix and the superelasticity of TiNiCr shape memory alloy.