Microstructural evolution and micro/meso-deformation behavior in pure copper processed by equal-channel angular pressing
Microstructural evolution and micro/meso-deformation behavior in pure copper processed by equal-channel angular pressing
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DOI：
10.1016/j.msea.2016.03.016
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发表时间：
2016-05
期刊：
影响因子：
6.4
通讯作者：
Jie Xu;Jianwei Li;D. Shan;B. Guo
中科院分区：
文献类型：
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作者：
Jie Xu;Jianwei Li;D. Shan;B. Guo
采用等通道转角挤压（ECAP）工艺，采用Bc路线，在模具通道角为110°的条件下对纯铜进行了ECAP加工。利用电子背散射衍射（EBSD）和透射电子显微镜（TEM）分析了ECAP变形过程中以及ECAP与微压缩结合后的组织和织构。经过12道次的ECAP加工，获得了平均晶粒尺寸约为0.5 µm的超细晶纯铜。微压缩过程中的各向异性行为是由ECAP工艺引入的纯铜微观织构引起的。在微压缩试验中，纯铜的ECAP变形表现出三种不同的应变软化行为。UFG纯铜细观变形的应变软化是由于高位错回复率加速位错湮灭所致，符合晶界滑动和晶粒旋转的变形机制。
Pure copper was processed by equal channel angular pressing (ECAP) using route Bc with a die channel angle of 110°. Electron back scattered diffraction (EBSD) and transmission electron microscopy (TEM) were used to analyze the microstructure and texture during ECAP processing and after combining ECAP with micro-compression. Ultrafine-grained pure copper with an average grain size of ~0.5 µm was achieved after ECAP processing through 12 passes. The anisotropic behavior during micro-compression is caused by the micro-texture of pure copper introduced by ECAP processing. Three kinds of strain softening behaviors are found during micro-compression tests in pure copper processed by ECAP. The strain softening of micro/meso deformation in UFG pure copper is caused by the accelerated dislocations annihilation due to the high dislocation recoveries at HAGBs, which is consistent with the deformation mechanism of grain boundary sliding and grain rotation.