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.