Atomic-Scale Investigation of Bismuth-Modulated Friction and Wear Behaviour of FeCrNi at Different Roughness

In this research, we have used molecular dynamics method to investigate the mechanism of the synergistic effect of surface roughness and Bi particle inclusions on the frictional wear phenomenon when diamond grinding balls rub against FeCrNi substrates. Due to the self-lubricating effect of Bi, the friction force is significantly reduced. Moreover, during the friction process, Bi will hinder the movement of dislocations to the inner part of the workpiece, which inhibits the generation of stress concentration phenomenon. Due to the non-uniformity of the friction contact area, the valley, surface and peak positions show different friction responses. The valley position shows the most intense wear and the most pronounced feedback to the friction force. Roughness, as an important influencing variable, is positively related to the wear rate of the workpiece. This investigation provides a reliable theoretical support for analysing the frictional wear behaviour of free-cutting steel in the Bi inclusions system.