Wear elements generated in the elementary process of wear

To clarify the mechanism of adhesive wear and establish a wear equation, it is necessary to investigate the amounts of wear elements (the elemental debris of wear particles) that transfer. The size and the quantity of wear elements on friction surface were examined for various sliding conditions and combinations of pure metals. By using a piezoelectric actuator, micro-scale friction experiments were performed by sliding a pin specimen once for a distance of 120 μm on a block specimen. Atomic-force microscopic observations of the friction surface were conducted after the experiments. Differences in the normal load and the lubrication conditions affect the quantity of wear elements more than their size. Furthermore, the size and the quantity of wear elements differed depending on the combination of materials. The quantity of the generated wear elements is related to the adhesion force between the two materials. A model is proposed for the generation and transfer of wear elements.