In situ analysis of rough contact closure by microtomography

Gap distribution and the true contact area significantly affect sealing performance and tribological properties of rough surfaces in contact. Current experimental approaches based on the measurement of the thermal or electric resistance, ultrasonic reflection coefficient, polymer or gold films are all limited in their ability to provide the three-dimensional (3D) surface separation. The aim of the proposal is to use in situ synchrotron micro-tomography for studying the mechanical contact between a hard rough surface and a softer metal. Using a special device developed at MINES Saint-Étienne, we want to follow in situ by micro-tomography the evolution of the aperture field and the real contact area at the roughness scale as a function of the applied load. The objective is to validate a semi-analytical model and a Finite Elements Model (FEM) of the contact between a hard and a soft metallic surface. The models are developed within the PhD thesis of the proposer at MINES Saint-Étienne.

间隙分布与真实接触面积，对接触粗糙表面的密封性能及摩擦学特性具有显著影响。当前基于热阻、电阻、超声反射系数测量，或依托聚合物/金薄膜的实验方法，在获取三维（3D）表面分离量方面均存在局限性。本研究提案旨在利用原位同步辐射显微断层成像技术，研究硬质粗糙表面与软质金属之间的机械接触行为。依托圣艾蒂安国立高等矿业学校（MINES Saint-Étienne）研发的专用装置，我们计划通过显微断层成像技术原位追踪粗糙度尺度下的间隙孔径场演化规律与真实接触面积随外加载荷的变化情况。本研究的目标是验证针对软硬金属表面接触问题的半解析模型与有限元模型（FEM）。上述模型均由本提案负责人在圣艾蒂安国立高等矿业学校（MINES Saint-Étienne）的博士阶段研究中开发完成。