铜单晶ECAE过程的剪切特征  

SHEAR CHARACTERISTICS OF COPPER SINGLE CRYSTAL DURING EQUAL CHANNEL ANGULAR EXTRUSION

作　　者：吴世丁[1] 李强[1] 姜传斌[1] 李广义[1] 王中光[1] 

机构地区：[1]中国科学院金属研究所材料疲劳与断裂国家重点实验室,沈阳110015

出　　处：《金属学报》2000年第6期602-607,共6页Acta Metallurgica Sinica

基　　金：国家自然科学基金!59871057

摘　　要：以铜单晶为模型材料，采用扫描电镜电子通道村度术（SEM－ECC）和透射电子显微技术，在不同尺度上研究了单次和两次等通道转角挤压（equalchannelangularextrusion，ECAB）过程的剪切形变特征，结果表明（1）一次ECAE挤压产生的剪切形变取向与理论预测相接近，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有所偏差，但仍能保持其各道次的剪切特征；（3）第2次ECAE后，剪切形变的不均匀性得到改善，组织更加细化，而且相邻亚晶取向差也有所增大。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.

关 键 词：铜单晶 剪切局部化 等通道转角挤压 剪切特征 

分 类 号：TG379[金属学及工艺—金属压力加工] TG146.11[一般工业技术—材料科学与工程]