Friction and Contact Ageing on Metal Surfaces

金属表面上的摩擦是一种具有最广泛技术相关性的现象，示例包括机械加工或移动电触点。接触金属之间的摩擦源于大量微观接触的形成和剪切。在这个实验项目中，我们发展的过程，确定微观金属接触摩擦的理解。摩擦力显微镜使我们能够以原子尺度的分辨率测量力，从而为相关的原子滑移面，塑性变形过程和能量耗散提供重要的见解。最近的研究结果表明，无论是工程模型的基础上的体积变形性能，也不是一个原子模型的基础上的界面相互作用是不够的，以描述接触形成，老化和滑动的微观现象。通过研究表面扩散，晶体取向，和表面钝化的分子膜对不同的金属表面的摩擦的影响，我们希望有助于金属之间的摩擦接触的预测模型，无论是微机械系统的设计和输入的理解宏观摩擦现象。

Friction on metal surfaces is a phenomenon of broadest technical relevance, examples include machining or moving electrical contacts. Friction between metals in contact originates in the formation and shearing of a multitude of microscopic contacts. In this experimental project we develop an understanding of the processes which determine friction of microscopic metallic contacts. Friction force microscopy allows us to measure forces with atomic-scale resolution and thus provides important insight into the relevant atomic glide planes, plastic deformation processes, and energy dissipation. Recent results indicate that neither an engineering model based on bulk deformation properties nor an atomistic model based on interfacial interactions are sufficient to describe the microscopic phenomena of contact formation, ageing, and sliding. By studying the effects of surface diffusion, of the crystallographic orientation, and of surface passivation by molecular films on friction for different metal surfaces we want to contribute to a predictive model for friction between metals in contact, both for the design of micromechanical systems and as input for an understanding of macroscopic friction phenomena.