铜基银膜摩擦特性的分子动力学研究

Molecular dynamics study on friction characteristics of silver films with copper-based

分子动力学方法是研究材料微观特性的重要手段之一,本文通过建立铜基银膜复合模型,并采用单个金刚石粗糙峰进行刻划,深入分析了刻划速度、系统温度以及刻划深度对摩擦特性的影响。随刻划速度和刻划深度的增加,摩擦进入稳定状态时所需的刻划距离增加,而系统温度的增加使之减小。刻划速度对摩擦过程的影响是变形相关的硬化和热效应的软化综合作用,产生层错带的不同运动方式;摩擦力随系统温度的增加而减小,主要与金属银的流变性能有关;随刻划深度增加,犁沟效应更加显著。

Molecular dynamics is one of the most important methods to study the microscopic properties of materials.In this paper,a composite model of silver film with copper-base is established and an asperity of diamond is used to scratch.The effects of scratching velocity,scratching depth and system temperature are investigated.With the increase of the scratching velocity and the scratching depth,the scratching distance needed for the friction process to enter a stable state increases,while the increase of the system temperature makes it decrease.The effect of the scratching velocity on the friction process is a combined results operated by work hardening and thermal softening,which lead to different modes of fault ribbon motion.The friction decreases with the system temperature,which is mainly related to the rheological properties of the Ag,and as the scratching depth increases,the furrow effect is more obvious.