挤压温度对Cu基形状记忆合金等通道转角挤压过程的影响  

Effect of Press Temperature on Equal Channel Angular Pressing (ECAP) to Cu-based Shape Memory Alloy

作　　者：李宁[1] 黄姝珂[1] 胥永刚[1] 文玉华[1] 莫华强[1] 

机构地区：[1]四川大学制造科学与工程学院,四川成都610065

出　　处：《热加工工艺》2005年第2期54-56,共3页Hot Working Technology

基　　金：高等学校博士学科点专项科研基金资助项目(20030610093)

摘　　要：研究了挤压温度对CuZnAl形状记忆合金等通道转角挤压(ECAP)过程的影响以及挤压后合金组织和性能的变化。结果表明,实验合金在室温下由于变形抗力过大无法进行 ECAP处理,而在 200℃、250℃、300℃、350℃时都能顺利进行挤压,但在200℃挤压时加工硬化严重,挤压过程无法多次进行;250℃虽无明显的加工硬化,但挤压多次时出现裂纹;350℃挤压晶粒长大比较严重,故本实验合金的最佳ECAP处理温度为 300℃。合金在上述四个温度挤压后,硬度都大幅度提高,力学性能得到提高;晶粒大小虽无明显减小,但晶界更加清晰,晶粒更加规则,特别是300℃挤压8次后形成了具有大角度晶界的等轴晶,微观组织得到优化。The effect of press temperature on ECAP process of Cu-25.04%Zn-3.83%Al-0.2%Zr(wt%) shape memory alloy, microstructure and mechanical property ware studied. Results show that because of big resistance of deformation the alloy can not do ECAP under room temperature, but can do ECAP under 200℃,250℃,300℃,350℃. The work-hardening is severe under 200℃ and the repeat numbers of ECAP are limitary. Though 250℃ is higher than the alloy′s recrystal temperature, when the numbers of ECAP is more there are cracks on sample. When do ECAP under 350℃, the grain size grows heavily, so the alloy′s best temperature of ECAP is 300℃. The alloy′s brinell hardness increases rapidly through ECAP under 200℃,250℃,300℃,350℃. The alloy′s grain size is not reduced clearly by ECAP under different temperature, but the grain boundary is more clear and the grains are more regular. Specially under 300℃, there are more wide-angle equiaxed grain formed and the microstructure is optimized.

关 键 词：等通道转角挤压 形状记忆合金 CUZNAL 挤压温度 

分 类 号：TG139.6[一般工业技术—材料科学与工程] TG376[金属学及工艺—合金]