(1. 西南交通大學 材料科學與工程學院，成都 610031；
2. 西南交通大學 牽引動力國家重點實驗室 摩擦學研究所，成都 610031)
摘 要: 采用分子動力學方法模擬了金剛石結(jié)構(gòu)粗糙體半球與三種不同晶體取向單晶鋯基體在不同滑移速度下的摩擦滑移過程，對摩擦力、磨損量進行了測量分析并結(jié)合位錯提取算法(DXA)對基體內(nèi)部結(jié)構(gòu)變形機理進行了研究。結(jié)果表明：較低滑移速度時犁耕作用占主要因素，各基體摩擦力區(qū)分更為明顯；較高滑移速度時原子間黏附作用是導致摩擦力升高的主要原因。磨損量隨滑移的進行持續(xù)增加，在所有滑移速度下[0001]取向基體磨損量均明顯大于其余兩者。通過DXA分析，指出不同晶體取向上滑移系開動情況發(fā)生變化是納米尺度下單晶鋯摩擦行為表現(xiàn)出較強晶體取向依賴性的主要原因。此外，基體切向位錯運動相比于法向?qū)渝e結(jié)構(gòu)對單晶鋯摩擦力響應和磨損量的影響更為顯著。
關鍵字: 單晶鋯；分子動力學；納米尺度；摩擦磨損；晶體取向
（1. School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031, China;
2. Tribology Research Institute, Traction Power State Key Laboratory, Southwest Jiaotong University, Chengdu 610031, China）
Abstract:The friction process of diamond structure hemisphere and single crystalline zirconium substrates with three different orientations were simulated using Molecular Dynamics method under different sliding velocities. The friction force and wear amount were detected and analyzed, the internal structure deformation mechanism was also studied with the Dislocations Extract Algorithm(DXA). The main results are as follows: the friction forces of different substrates are more distinct at lower sliding velocities due to the dominance of plouging effect while the adhesion between atoms at the higher sliding velocities is the main reason for the significant increase in friction. The wear amount continues to increase as the sliding proceeds, and the wear amount of [0001] oriented substrate is significantly greater than the others. Through the DXA analysis, it is indicated that the change of the slip system in different orientations is the main reason for the strong crystal orientation dependence of friction and wear behaviors of the single crystal zirconium at the nanoscale. Moreover, the effects of tangential dislocation motion on the friction force and wear amount of single crystal zirconium are more significant than those of normal stacking fault.
Key words: single crystalline zirconium; molecular dynamics; nanoscale; friction and wear; crystal orientation
