循环应变对快速凝固制备Ti_(49)Ni_(51)形状记忆合金组织和性能的影响  

Effect of Cyclic Strain on Microstructure and Properties of Ti_(49)Ni_(51) Shape Memory Alloy Prepared by Rapid Solidification

作　　者：黄斌[1] 孟凡莹[1] 丁镠 武俊霞 张薇 王永善[1] 李培友[1] HUANG Bin;MENG Fanying;DING Liu;WU Junxia;ZHANG Wei;WANG Yongshan;LI Peiyou(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,汉中723001

出　　处：《机械工程材料》2022年第5期16-21,共6页Materials For Mechanical Engineering

基　　金：陕西省教育厅专项资金资助项目(16JK1138);陕西理工大学博士科研启动基金资助项目(SLGKYQD2-22)。

摘　　要：采用快速凝固技术制备Ti_(49)Ni_(51)合金棒,在10℃环境温度下对铸态合金棒进行不同循环应变(5.0%,6.0%,6.5%)下的准静态加卸载压缩试验,研究了循环应变对合金组织和性能的影响,并讨论了不同循环应变下合金的超弹性行为。结果表明:3种循环应变下试验后Ti_(49)Ni_(51)合金均由B2-TiNi基体相、Ti_(3)Ni_(4)析出相和Ti_(2)Ni析出相组成,随着循环应变增加,等轴状B2-TiNi相晶粒逐渐被拉长,Ti_(3)Ni_(4)相增多,晶界处部分Ti_(3)Ni_(4)相受挤压作用发生聚集,尺寸变大;3种循环应变下合金的应力-应变曲线均存在马氏体相变应力平台,5.0%循环应变下该应力平台较不明显;6.0%和6.5%循环应变下,随循环次数增加,耗散能下降而可恢复应变能密度增加,与循环应变为6.0%时相比,6.5%循环应变下的耗散能略低,而可恢复应变能密度较高;Ti_(49)Ni_(51)合金具有良好的超弹性;合金硬度随循环应变增加而增大。Ti_(49)Ni_(51) alloy rods were prepared by rapid solidification technique,and the as-cast alloy rods were subjected to quasi-static loading and unloading compression tests under different cyclic strains(5.0%,6.0%,6.5%)at an ambient temperature of 10℃.The effects of cyclic strains on the microstructure and properties of the alloy were studied,and hyperelastic behavior of the alloys under different cyclic strains was discussed.The results show that the Ti_(49)Ni_(51) alloy after test was composed of B2-TiNi matrix phase,Ti_(3)Ni_(4) precipitation phase and Ti_(2)Ni precipitation phase under three cyclic strains.With increasing cyclic strain,the equiaxed B2-TiNi grains were gradually elongated,and the Ti_(49)Ni_(51) phase increased,and part of the Ti_(3)Ni_(4) phase at the grain boundary aggregated and became larger due to extrusion.Martensitic transformation stress platform existed in the stress-strain curves of the alloy under three cyclic strains,and the stress platform was not obvious under 5.0% cyclic strain.Under 6.0% and 6.5% cyclic strains,with increasing number of cycles,the dissipative energy decreased while the recoverable strain energy density increased.Compared with those under 6.0% cyclic strain,the dissipated energy under 6.5% cyclic strain was slightly lower,while the recoverable strain energy density was higher.The Ti_(49)Ni_(51) alloy had good hyperelasticity.The hardness of the alloy increased with increasing cyclic strain.

关 键 词：钛镍合金 形状记忆合金 循环应变 显微组织 超弹性 

分 类 号：TG146.2[一般工业技术—材料科学与工程]