Effects of surface nanostructure on boundary lubrication using molecular dynamics

Molecular dynamics simulations are used to study the boundary lubrication behaviors of squalane lubricant between two iron wall structures during shearing at different pressures and temperatures. Boundary lubrication models with a smooth iron wall and a nanostructured iron wall, respectively, are constructed, and the density distribution of the lubricating film and the velocity distribution in the shearing process are analyzed. The mechanical response of the solid wall is output, and the friction coefficient is calculated. A tribological test is performed with a UMT-2 tribometer under sliding conditions to evaluate the reliability of the simulation method. The results show that the surface nanostructure has a significant effect on the film thickness and delamination of the lubricating film but little effect on the velocity distribution of the lubricating film. The nano strip groove helps to reduce the friction coefficient of the boundary lubrication system.