(1. 西南交通大学 材料科学与工程学院，成都 610031；
2. 西南交通大学 牵引动力国家重点实验室 摩擦学研究所，成都 610031)
摘 要: 采用分子动力学方法模拟了金刚石结构粗糙体半球与三种不同晶体取向单晶锆基体在不同滑移速度下的摩擦滑移过程，对摩擦力、磨损量进行了测量分析并结合位错提取算法(DXA)对基体内部结构变形机理进行了研究。结果表明：较低滑移速度时犁耕作用占主要因素，各基体摩擦力区分更为明显；较高滑移速度时原子间黏附作用是导致摩擦力升高的主要原因。磨损量随滑移的进行持续增加，在所有滑移速度下[0001]取向基体磨损量均明显大于其余两者。通过DXA分析，指出不同晶体取向上滑移系开动情况发生变化是纳米尺度下单晶锆摩擦行为表现出较强晶体取向依赖性的主要原因。此外，基体切向位错运动相比于法向层错结构对单晶锆摩擦力响应和磨损量的影响更为显著。
关键字: 单晶锆；分子动力学；纳米尺度；摩擦磨损；晶体取向
（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
