文献类型：期刊文献

英文题名：Understanding the linear relation between pop-in excursion length and critical force for spherical nanoindentation

作者：Zhou, Nian Elkhodary, Khalil, I Zhang, Ling Tang, Shan

第一作者：周念;Zhou, Nian

通信作者：Zhang, L[1];Tang, S[2]

机构：[1]Guizhou Inst Technol, Sch Mat & Met Engn, Guiyang, Guizhou, Peoples R China;[2]Chongqing Univ, Coll Mat Sci & Engn, Chongqing 400044, Peoples R China;[3]Amer Univ Cairo, Dept Mech Engn, New Cairo, Egypt;[4]Dalian Univ Technol, Int Res Ctr Computat Mech, Dept Engn Mech, State Key Lab Struct Anal Ind Equipment, Dalian 116023, Peoples R China

第一机构：贵州理工学院材料与冶金工程学院

通信机构：corresponding author), Chongqing Univ, Coll Mat Sci & Engn, Chongqing 400044, Peoples R China;corresponding author), Dalian Univ Technol, Int Res Ctr Computat Mech, Dept Engn Mech, State Key Lab Struct Anal Ind Equipment, Dalian 116023, Peoples R China.

年份：2021

卷号：101

期号：11

起止页码：1343-1363

外文期刊名：PHILOSOPHICAL MAGAZINE

收录：;EI(收录号：20211310130642);Scopus(收录号：2-s2.0-85102944610);WOS:【SCI-EXPANDED(收录号:WOS:000632001200001)】；

基金：The financial supports from National Natural Science Foundation of China (NSFC) under grant Nos. 11872139 and 51671039, and Open Project of State Key Laboratory of Superhard Materials (Jilin University) (201905) are appreciated. Ling Zhang wish to thank the financial support of The National Key Research & Development Program of China (No.2016YFB0700403) and Project No. 2020CDJDPT001 supported by the Fundamental Research Funds for the Central Universities.

语种：英文

外文关键词：Nanoindentation; molecular dynamics; pop-in; dislocation structures; Taylor models

摘要：Pop-in is a widely observed phenomenon in nanoindentation. In this paper, dislocation evolution in pop-in processes is analysed in detail through molecular dynamics (MD) simulations. We found that a large number of dislocations nucleate homogeneously at the initiation of pop-in, followed by extensive dislocation propagation, which is the dominant mode of plastic deformation during pop-in. Moreover, we noted that establishing the correct dislocation evolution mechanisms of pop-in can serve to explain the overshoot phenomenon observed in nanoindentation experiments. Through our MD analysis on the obtained dislocation structures, therefore, we were able to propose a model that can predict the total length of dislocations associated with the plastic processes underneath a spherical indenter. In addition, the Taylor model was used to verify that our proposed dislocation length model sits well with the MD simulated force-displacement curves of nanoindentation. In fact, the MD simulated linear relation between critical force and indentation depth during pop-in is consistent with the Hertzian and Taylor models. Our MD simulations, therefore, can provide significant insight into the experimentally observed pop-in phenomena.