In-situ observations of fretting behaviour by using a small piezoelectric testing apparatus under laser microscope

摘要

Although fretting damage is a phenomenon occurring at contact interfaces hidden by two contacting bodies, the in-situ or direct observation is necessary to investigate the mechanism of the phenomenon and its process. In this paper, a small specially designed piezoelectric fretting wear testing apparatus, was developed for the purpose. The polymethyl methacrylate (PMMA) plate, having an aluminium coated film and protection coating layer, and PMMA ball were used as ball-on flat fretting wear test specimens. The damage process of crack initiation, propagation and the mealtime roughness change in the coating layers were directly observed and evaluated by using a laser microscope with a profile measuring function.