tailieunhanh - Báo cáo hóa học: " Effects of Crystalline Anisotropy and Indenter Size on Nanoindentation by Multiscale Simulation"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Effects of Crystalline Anisotropy and Indenter Size on Nanoindentation by Multiscale Simulation | Nanoscale Res Lett 2010 5 420-432 DOI s11671-009-9500-x NANO EXPRESS Effects of Crystalline Anisotropy and Indenter Size on Nanoindentation by Multiscale Simulation Junwan Li Yushan Ni Hongsheng Wang Jifa Mei Received 20 October 2009 Accepted 19 November 2009 Published online 27 November 2009 The Author s 2009. This article is published with open access at Abstract Nanoindentation processes in single crystal Ag thin film under different crystallographic orientations and various indenter widths are simulated by the quasicontinuum method. The nanoindentation deformation processes under influences of crystalline anisotropy and indenter size are investigated about hardness load distribution critical load for first dislocation emission and strain energy under the indenter. The simulation results are compared with previous experimental results and Rice-Thomson R-T dislocation model solution. It is shown that entirely different dislocation activities are presented under the effect of crystalline anisotropy during nanoindentation. The sharp load drops in the load-displacement curves are caused by the different dislocation activities. Both crystalline anisotropy and indenter size are found to have distinct effect on hardness contact stress distribution critical load for first dislocation emission and strain energy under the indenter. The above quantities are decreased at the indenter into Ag thin film along the crystal orientation with more favorable slip directions that easy trigger slip systems whereas those will increase at the indenter into Ag thin film along the crystal orientation with less or without favorable slip directions that hard trigger slip systems. The results are shown to be in good agreement with experimental results and R-T dislocation model solution. Keywords Multiscale Quasicontinuum method Nanoindentation Anisotropy Size effect J. Li Y. Ni H H. Wang J. Mei Department of Mechanics and Engineering Science Fudan University 200433