Friction and wear study of metallic contacts under dry sliding conditions: A molecular dynamics simulation-based approach

Sliding friction originating due to ploughing and adhesive wear significantly affects the performance of small-scale components, that is, nano-electromechanical systems/micro-electromechanical. To get a comprehensive understanding of the friction mechanisms, a comprehensive study of surface interactions at the nanoscale is crucial, particularly when dealing with nano-electromechanical and micro-electromechanical components. This study performed molecular dynamics simulation to explore the interactions between asperities (made of similar/dissimilar materials) at the nanoscale under dry sliding conditions. The research framework focuses on modelling the contact between two hemispherical asperities during dry sliding by considering three material combinations: soft-to-soft (Cu–Cu), hard-to-hard (Fe–Fe), and hard-to-soft (Fe–Cu). The study assesses plastic deformation and atomic wear at specific sliding speeds. Notably, the results indicate that the frictional force on the lower asperity increases as interference increases. Additionally, atomic wear rises with increased interference in the case of the Fe–Cu tribopair. Particularly high atomic wear is observed in the Cu–Cu tribopair due to the ease of slip within the face-centred cubic crystal structure of copper.