冷变形对TiNiCr形状记忆合金超弹性和组织的影响

Effects of Cold Deformation on Super-elasticity and Microstructure of TiNiCr Shape Memory Alloys

通过拉伸试验和对光学显微组织照片的观察,研究了不同的冷轧变形量对TiNiCr形状记忆合金超弹性和显微组织的影响。试验表明,TiNiCr形状记忆合金弹性随着冷轧变形量的增加而增加,当冷轧变形量达到33%之后,弹性的增加不明显,单纯的冷变形不能使TiNiCr达到完全的非线性超弹性;冷变形会使TiNiCr产生一种马氏体变体,当变形量达到27%时,这种马氏体变体的体积随着变形量的增加而长大,而马氏体变体的错乱程度随变形量的增大一直在增加。

Effects of different cold-rolled deformation rates on super-elasticity and microstructure of TiNiCr shape memory alloys have been investigated by tensile testing and optical microscopeom.Experimental results indicate that the super-elasticity of TiNiCr shape memory alloys can be increased with increasing in cold deformation rate,however,itsincerease can be ignored with the cold deformation rate more than 33%.In addition,totally non-linear super-elasticity of the alloy can not be obtained in the condition of cold deformation.A martensite variant can be created in the TiNiCr shape memory alloys during cold deformation,whose volume would be increased with the increase of cold deformation rate when the cold deformation rate is more than 27%,and whose dislocation is increased with the increase of cold deformation rate.