Quasicontinuum simulation of indentation on FCC metals  

作　　者：王华滔 秦昭栋 倪玉山 张文 

机构地区：[1]Department of Mechanics and Engineering Science,Fudan University

出　　处：《中国有色金属学会会刊：英文版》2008年第5期1164-1171,共8页Transactions of Nonferrous Metals Society of China

基　　金：Project(10576010) supported by the National Natural Science Foundation of China and NSAF Foundation of China

摘　　要：Quasicontinuum simulations were performed to study the processes of incipient plastic deformation on three FCC metals (Ag,Ni and Pd) under the action of a rigid indenter.Four widths (9.3,18.6,27.9 and 37.2 ) of the indenters were modelled for each metal specimen.A series of load-displacement responses and the strain energy versus displacement responses of the indenter were presented.It is shown that the abrupt drop of the load in the load-displacement response is triggered by the nucleation of dislocations in the metals.The critical load of each metal specimen increases with the increase of the indenter width,while the hardness of the metal specimen decreases as the indenter width increases.Furthermore,the microscopic mechanism of deformation in the films was analyzed.Two dislocations are nucleated respectively beneath the right and left sides of the indenter.Each dislocation successively decomposes into two Shockley partial dislocations after the first nucleation process.The distances between the two partial dislocations are equal for both sides of the indenter,which are in agreement with the theoretical values.Quasicontinuttm simulations were performed to study the processes of incipient plastic deformation on three FCC metals （Ag, Ni and Pd） under the action of a rigid indenter. Four widths （9.3, 18.6, 27.9 and 37.2 A） of the indenters were modelled for each metal specimen. A series of load--displacement responses and the strain energy versus displacement responses of the indenter were presented. It is shown that the abrupt drop of the load in the load--displacement response is triggered by the nucleation of dislocations in the metals. The critical load of each metal specimen increases with the increase of the indenter width, while the hardness of the metal specimen decreases as the indenter width increases. Furthermore, the microscopic mechanism of deformation in the films was analyzed. Two dislocations are nucleated respectively beneath the right and left sides of the indenter. Each dislocation successively decomposes into two Shockley partial dislocations after the first nucleation process. The distances between the two partial dislocations are equal for both sides of the indenter, which are in agreement with the theoretical values.

关 键 词：FCC金属材料 微错 成核作用 印压方式 

分 类 号：TG115[金属学及工艺—物理冶金]