Molecular dynamics simulation of severe adhesive wear on a rough aluminum substrate

Severe adhesive wear on a rough aluminum (Al) substrate is simulated by a hard Lennard-Jones asperity impacting an Al-asperity at high speeds using molecular dynamics (MD). Multiple simulations investigate the effects of variations in the inter-asperity bonding, the geometric overlap between two asperities, the relative impact velocity and the starting temperature. The effect of these experimental variables on degree of adhesive wear and the temperature profiles are discussed, and a design of experiments method is used to help interpret the results. The results indicate that increasing the inter-asperity bonding, the geometric overlap and the starting temperature of two asperities will substantially increase the wear rate, while raising the impact velocity slightly decreases the wear rate. It is observed that the deformation mechanism involves local melting and the formation of a liquid like layer in the contact area between two asperities, and the amorphous deformation of the Al-asperity.