Tribological characteristics of three-body abrasive wear on MoS2 films

Abstract

Abstract Aiming at the problem of the failure of bearing lubrication caused by the entry of fine dust into the spacecraft, a molecular dynamic simulation method was proposed to study the wear characteristics of the bearing lubricating film. Firstly, the atomic model of MoS2 thin film is established, and the contact state of dust particles on the surface of MoS2 thin film is divided (two-body contact state and three-body contact state). Secondly, the characteristics of two-body and three-body abrasive wear are studied by applying different loads to the abrasives. Finally, the surface structure of the substrate was changed to explore the adsorption and wear characteristics of the one-dimensional rough substrate. The following conclusions are obtained: 1) Two-body contact and three-body contact have different wear mechanisms. The wear of two-body contact originates from the accumulation and release of tangential force. The main source of wear in three-body contact is the release of tangential force and the action of tangential force caused by rolling; 2) The relationship between sliding friction and rolling friction at the atomic scale is the same as that at the macroscopic scale. Rolling friction is much less friction than sliding friction. Rolling friction causes less damage to the film than sliding friction; 3) The one-dimensional rough substrate reduces the contact area between the film and the film, resulting in a decrease in the adsorption between the film and the substrate. The asperity structure of rough substrates reduces the lubricity of the film compared to smooth substrates.