计算机模拟晶界位向对双晶体循环形变行为的影响  

SIMULATION OF CYCLIC DEFORMATION OF BICRYSTAL WITH DIFFERENT GRAIN BOUNDARY ORIENTATIONS

作　　者：王明章[1,2] 李小燕 林实[1,2] 王中光[1,2] 肖纪美[1,2] 

机构地区：[1]北京科技大学材料物理系 [2]中国科学院金属研究所材料疲劳与断裂国家重点实验室

出　　处：《金属学报》1999年第1期27-31,共5页Acta Metallurgica Sinica

基　　金：国家自然科学基金

摘　　要：在实验基础上，用晶体细观力学方法模拟研究了纯铝双晶体在应力轴与晶界面分别垂直或平行时的循环形变过程．计算显示，在这两种加载方式下晶界区微观应力应变分布均有显著的变化，而它们各自晶界区微观应力应变分布又有明显不同，这和实验发现晶界区的形变损伤比晶内其它区域更大，以及这两种加载方式下晶界及晶界区形变损伤有很大差异的结果是一致的．利用计算得到的瞬时滑移系开动及分布情形对有关实验观测结果进行分析，能够满意地说明包括交滑移变形在内的晶界影响区的形成，并且发现循环变形时的晶界影响区与拉伸变形阶段相比更加局域化．同时，模拟循环变形曲线还显示了这两种加载方式下双晶体反向过渡区加工硬化行为的区别，平行晶界加载时过渡区内加工硬化更高，而过渡区应变则减小．The cycilc deformation processes of two aluminium bicrystal specimens with the same grain boundary (GB) and with the stress axes perpendicular and parallel to the GB respectively had been numerically simulated by using a crystalline micromechanical model. The results were analyzed and compared with the experimental facts. The slip processes were instantaneously reproduced, which can satisfactorily explain the formation of the GB effect zones. The differences in the internal stress and strain distribution in the two specimens were revealed clearly, which might be responsible for the different deformation behavior and the damage process in the GB zones. The reverse transition work-hardening behavior on the cyclic deformation curves obtained from the two specimens was also found to be different. All of these strongly indicated and clarified the significant effects of GB orientation on the cyclic deformation be havior of the bicrystal and the damage process at the GB.

关 键 词：晶界 循环变形 双晶体 计算机模拟 

分 类 号：TG111.7[金属学及工艺—物理冶金] TP391.9[金属学及工艺—金属学]