研究了Cu-25.04Zn-3.83Al-0.2Zr形状记忆合金的ECAP过程以及不同温度挤压后组织和性能的变化.结果表明:在 200℃挤压时加工硬化严重,无法进行多次挤压,250℃虽无明显的加工硬化,但挤压多次会出现裂纹,350℃挤压晶粒长大比较严重,较佳ECAP温度为300℃;合金在300℃经过一次挤压后,硬度从149HB陡增到252HB,随着挤压次数的增加,硬度略有增加并趋于稳定,达到275HB左右;合金在300℃挤压后,晶粒虽无明显减小,但晶界更加清晰,晶粒更加规则,形成了具有大角度晶界的等轴晶,微观组织得到优化.

The equal channel angular pressing(ECAP) process,mechanical properties and microstructure of Cu-25.04%Zn-3.83%Al-0.2%Zr(wt％) shape memory alloy were studied.The alloy could be processed with ECAP at 200℃,250℃,300℃,350℃,but the work-hardening was severe when processed at 200℃ and the repeat numbers of ECAP were limitary.Though 250℃ was higher than the alloy's recrystal temperature,when the numbers of ECAP increased there were cracks on the sample.The grain size grew heavily at 350℃,so the alloy's best temperature of ECAP was 300℃.The alloys Brinell hardness increased rapidly from 149 to 252 through the first ECAP at 300℃,then it increased slowly and tended to be stable with the increasing of the number of ECAP.The alloys grain size did not reduce clearly by ECAP at 300℃,but the grain boundaries were more clear and the grains were more regular.There were more wide-angle equiaxed grains and the microstructure was optimized.