循环变形对纳米晶TiNiFe记忆合金马氏体相变超弹性的影响  

Effect of cyclic deformation on superelasticity of martensitic transformation of nanocrystalline TiNiFe memory alloy

作　　者：李亚鹏[1] 武泽园 张会[1] 廖仲尼 王涛涛 LI Ya-peng;WU Ze-yuan;ZHANG Hui;LIAO Zhong-ni;WANG Tao-tao(School of Materials Science and Engineering,Shaanxi University of Technology,Hanzhong 723001,China)

机构地区：[1]陕西理工大学材料科学与工程学院,陕西汉中723001

出　　处：《材料热处理学报》2024年第9期145-149,共5页Transactions of Materials and Heat Treatment

基　　金：陕西省科技厅重点研发项目(2024GX-YBXM-361);陕西省科技厅重点研发项目(2024GX-YBXM-376);陕西省自然科学基金项目(2024JC-YBQN-0366)。

摘　　要：采用拉拔变形及低温退火获得了平均晶粒尺寸为15 nm的Ti_(50)Ni_(48)Fe_(2)(原子分数)记忆合金丝材,通过拉伸实验机研究了拉伸应变为6%及20次循环变形对纳米晶TiNiFe记忆合金应力诱发马氏体相变超弹性的影响。结果表明:当循环变形次数由1次增加至20次,纳米晶TiNiFe合金马氏体相变的超弹应力由871 MPa减小至723 MPa,残余应变由0.53%增加至0.73%。本文中的纳米晶TiNiFe合金在循环变形后呈现出高超弹应力和小残余应变,明显优于已经报道的TiNi记忆合金。这主要是由于纳米晶TiNiFe合金中高密度晶界产生的细晶强化和Fe元素产生的固溶强化,由此抑制了合金中位错的产生从而提高了马氏体相变的超弹稳定性。Ti_(50)Ni_(48)Fe_(2)(atomic fraction)memory alloy wire with an average grain size of 15 nm was obtained by drawing deformation and low-temperature annealing.The effect of tensile strain of 6%and 20 cycles of cyclic deformation on stress induced martensitic transformation superelasticity of nanocrystalline TiNiFe memory alloy was studied using a tensile testing machine.The results show that when the number of cyclic deformations increases from 1 to 20,the superelastic stress of martensitic transformation in the nanocrystalline TiNiFe alloy decreases from 871 MPa to 723 MPa,and the residual strain increases from 0.53%to 0.73%.The nanocrystalline TiNiFe alloy in this article exhibits high superelastic stress and small residual strain after cyclic deformation,which is significantly better than the reported TiNi memory alloy.This is mainly due to the fine grain strengthening generated by high-density grain boundaries and the solid solution strengthening generated by Fe element in nanocrystalline TiNiFe alloy,which suppresses the generation of dislocations in the alloy and improves the superelastic stability of martensitic transformation.

关 键 词：记忆合金 NiTiFe 马氏体相变 超弹性 循环变形 

分 类 号：TG139.6[一般工业技术—材料科学与工程]