Molecular dynamics study on the nano-void growth and coalescence at grain boundary  

作　　者：LIN EnQiang NIU LiSha SHI HuiJi DUAN Zheng 

机构地区：[1]Applied Mechanics Laboratory, School of Aerospace, Tsinghua University, Beijing 100084, China

出　　处：《Science China(Physics,Mechanics & Astronomy)》2012年第1期86-93,共8页中国科学：物理学、力学、天文学（英文版）

基　　金：supported by the Open Foundation of State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology (Grant No. KFJJ11-0Y);the National Basic Research Program of China (Grant No. 2010CB631005);the National Natural Science Foundation of China (Grant Nos. 11172148 and 51071094)

摘　　要：Molecular dynamics simulations using embedded atom method (EAM) potential were performed to study nano-void growth and coalescence at grain boundary in face-centered cubic bicrystal copper. Thin-plate specimens subjected to uniaxial tension strain with one-void and two-void at the centered grain boundary were employed to analyze the effect of specimen size, temperature and applied strain rate on the stress-strain response, incipient yield strength and macroscopic effective Young's modulus. The evolutions of dislocations, twin bands and void shapes under different specimen sizes were also presented. The obtained results show that, regardless of the void numbers, the specimen sizes, temperature, the applied strain rate had significant influence on the void shape evolution, stress-strain curve and incipient yield strength, while negligible effects on the macroscopic effective Young's modulus except for the temperature. Moreover, the voids growth rate along the grain boundary was also found to be associated with the specimen sizes.Molecular dynamics simulations using embedded atom method （EAM） potential were performed to study nano-void growth and coalescence at grain boundary in face-centered cubic bicrystal copper. Thin-plate specimens subjected to uniaxial tension strain with one-void and two-void at the centered grain boundary were employed to analyze the effect of specimen size, temperature and applied strain rate on the stress-strain response, incipient yield strength and macroscopic effective Young＇s modulus. The evolutions of dislocations, twin bands and void shapes under different specimen sizes were also presented. The obtained results show that, regardless of the void numbers, the specimen sizes, temperature, the applied strain rate had signifi- cant influence on the void shape evolution, stress-strain curve and incipient yield strength, while negligible effects on the macroscopic effective Young＇s modulus except for the temperature. Moreover, the voids growth rate along the grain boundary was also found to be associated with the specimen sizes.

关 键 词：BICRYSTAL void growth void coalescence grain boundary molecular dynamics simulations embedded atom method 

分 类 号：TG111.4[金属学及工艺—物理冶金] TB34[金属学及工艺—金属学]