文献类型：期刊文献

英文题名：The effect of grain boundary structures on crack nucleation in nickel nanolaminated structure: A molecular dynamics study

作者：Yang, Xiao-Feng[1];He, Chen-Yun[1];Yuan, Guang-Jian[1];Chen, Hao[1];Wang, Run-Zi[1];Jia, Yun-Fei[1];Zhang, Xian-Cheng[1];Tu, Shan-Tung[1]

机构：[1]East China Univ Sci & Technol, Sch Mech & Power Engn, Key Lab Pressure Syst & Safety, Minist Educ, Meilong Rd 130, Shanghai 200237, Peoples R China

年份：2021

卷号：186

外文期刊名：COMPUTATIONAL MATERIALS SCIENCE

收录：;EI(收录号：20203609139921);WOS:【SCI-EXPANDED(收录号:WOS:000594753000001)】；

基金：The authors would like to acknowledge gratefully for the financial support through NSFC of China (51725503, 51575183, 51805501) and 111 Project. HC acknowledges the support by Shanghai Sailing Program (20YF1409400). And Zhang XC is also grateful for the support by Major Program of National Natural Science Foundation of Shanghai (2019-01-07-00-02-E00068).

语种：英文

外文关键词：Nanolaminated nickel; Molecular dynamics; Crack nucleation; Grain boundary structures

摘要：Molecular dynamics (MD) simulations were performed to explore the structures, energies and tensile properties of grain boundaries (GBs) as well as crack nucleation in nickel nanolaminated (Ni NL) structures. Four typical textures observed in experiments (Liu et al., 2013) [6] were considered in this paper. Results showed that low-angle GBs consist of a series of periodically arranged dislocations while high-angle GBs are composed of disordered phase for all textures. GB energies increase linearly with increasing misorientation in the range of lowangle GBs (0-10 degrees). Then, the growth rate of energies slows down and finally stabilizes when the misorientation angle reaches 30 degrees. Among four textures, {111} < 110 > texture has the highest GB energy while {110} < 111 > texture the lowest one. The tensile properties of NL structures with different textures and misorientations were further investigated. Results showed that the tensile properties depend primarily on textures, while weakly on GB energies and dislocation densities. {111} < 112 > texture possesses the best combination of high-strength and ductility among the four textures. Furthermore, the evolution of dislocation density and structure as well as the nucleation of crack were analysed. Crack nucleates at the junction between Shockley partial dislocations and twin boundaries generated during deformation for low-angle GBs, while at the location where Shockley partial dislocations and the original disordered GBs intersect for high-angle GBs. Our results provide a fundamental understanding of GB structures and deformation mechanisms of Ni NL structures.