Molecular dynamics simulation of nanoscale contact and sliding processes for probes with different tip radius of curvature  

作　　者：Xiaojing Yang Shengpeng Zhan 

机构地区：[1]Faculty of Mechanical and Electrical Engineering, Kunming University of Science and Technology

出　　处：《Chinese Science Bulletin》2014年第13期1468-1478,共11页

基　　金：supported by the National Natural Science Foundation of China(11062003 and 51365021);Yunnan Provincial Application Foundation Research Project(2009ZC042M)

摘　　要：Three-dimensional molecular dynamics(MD)simulations were carried out to study the contact and sliding processes between diamond points with different tip radius of curvature and surfaces of single crystal copper.The material deformation,abrasion mechanism,lattice defects,the force of contact process,and the sliding friction process were investigated.The simulation results show that the contact force,dislocations,and stacking fault defects,increase during the contact process with increasing contact depth or tip radius of curvature.The dislocations emit along the 10"1and"10"1direction and then a glide band is formed.It was also found that a greater tip radius of curvature results in a larger groove and more material deformation.The normal force and friction increase with increasing tip radius of curvature,but the coefficient of friction decreases.The stacking faults spread along the sliding direction and increase with increasing tip radius of curvature.In addition,the number of upheaval atoms increases as the radius of tip curvature or sliding distance increases.Three-dimensional simulations were carried out molecular dynamics （MD） to study the contact and sliding processes between diamond points with different tip radius of curvature and surfaces of single crystal copper. The material deformation, abrasion mechanism, lattice defects, the force of contact process, and the sliding friction process were investigated. The simulation results show that the contact force, dislocations, and stacking fault defects, increase during the contact process with increasing contact depth or tip radius of curvature. The dislocations emit along the [10i-] and [i-01] direction and then a glide band is formed. It was also found that a greater tip radius of cur- vature results in a larger groove and more material defor- mation. The normal force and friction increase with increasing tip radius of curvature, but the coefficient of friction decreases. The stacking faults spread along the sliding direction and increase with increasing tip radius of curvature. In addition, the number of upheaval atoms increases as the radius of tip curvature or sliding distance increases.

关 键 词：分子动力学模拟 曲率半径 刀尖半径 滑动过程 纳米接触 探针 晶格缺陷 位错发射 

分 类 号：O411.3[理学—理论物理] O472[理学—物理]