表面机械研磨处理的纯铜拉伸形变机制

采用扫描电镜电子通道衬度技术(SEM-ECC)研究了表面机械研磨处理(SMAT)铜表面在室温拉伸的形变特征.结果表明:剪切带是纳米晶层、亚微晶层以及由位错胞组成的过渡层的共同形变特征,在不同的结构表层,剪切带的形貌略有差别.纳米晶层和亚微晶层内的剪切带主要为沿平面界面剪切滑动的结果,而过渡层的形变主要是以SMAT处理前的初始晶粒为单元发生的,剪切带的形成基本符合晶体学规律.

Tensile deformation mechanism in pure copper subjected to surface mechanical attrition treatment

The ambient tensile deformation characteristics of copper subjected to the surface mechanical attrition treatment (SMAT) was investigated by means of the electron channeling contrast in scanning electron microscopy (SEM-ECC). It was found that during tensile the shear bands were the common deformation characteristics in nano-grained layer, submicro-grained layer and transition layer formed by dislocation cells. The morphology of the shear bands slightly varied in the surface layer with different structures. The shear bands both in nano-grained layer and submicro-grained layer were formed as a result of the shear sliding along a planar interface. The tensile deformation in transition layer mainly occurred in a scale of the original grains. The shear bands were formed basically according with the rule of crystallography.