铜单晶ECAE过程的剪切特征

以铜单晶为模型材料，采用扫描电镜电子通道衬度术（ＳＥＭ－ＥＣＣ）和透射电子显微技术，在不同民度上研究了单次和两次等通道转角挤压过程珠剪切形变特征结果表明：（１）一次ＥＣＡＴ挤压产生的剪切形变取向与理论预测和相接近，但剪切形变表现出局部化特征，出现了微观尺度上的剪切带；（２）两次ＥＣＡＥ产生的两套剪切带间存在着交互作用，导致剪切带出现分叉现象，方向也与理论预测结果与偏差，但仍能保持其各道 剪切特征

SHEAR CHARACTERISTICS OF COPPER SINGLE CRYSTAL DURING EQUAL CHANNEL ANGULAR EXTRUSION

The shear characteristics of copper single crystals during a single and double passage of equal channel angular extrusioll ECAE were investigated at different scales by using SEM-electron channel contrast and TEM techniques. It was found that the shear deformation associated with the single passage of ECAE is approximately coasistent with the theoretical predication but presents in the form of shear bands. There ekists an obvious ioteraction between the two groups of shear bands formed in the fort and second passage of ECAE, resulting in the divergence of the shear bands and a few degrees deviation angle between the orientation of shear band and theoretical orientation. The second otrusha results in the homogenization of shear deformation, the refinement of microstructure and the incrase in dsorientation between the neighboring subgrains.