Current-carrying tribological behavior of textured Au/MoS2 coatings in vacuum

Abstract

Sliding electrical contact has been widely used in spacecraft such as slip ring for solar windsurfing, and its service life directly affects that of the spacecraft. Au as a sliding electrical contact material has been widely used in aerospace equipment, but poor lubricity limits its service life. To address this issue, this study introduces MoS2 into the texturing holes of the Au coating, which can improve the lubricity, and maintain the continuity of Au and thus its conductivity. Additionally, the effect of texture density on the vacuum current-carrying tribological properties of the textured Au/MoS2 coating was investigated. The results indicate that texture not only reduces the mechanical properties of the coating but also affects the amount of MoS2 that can be filled. A high texture density greatly reduced the carrying capacity, leading to serious abrasive wear. However, low texture density results in serious adhesive wear owing to insufficient lubricity. Under an appropriate texture density, excellent vacuum current-carrying tribological behaviour can be achieved depending on the formation of a transfer film of MoS2 and Au, which maintains conductivity through Au and provides lubricity through MoS2. This study is of great significance in prolonging the service life of sliding electrical contacts and provides a new idea for the design of sliding electrical contact materials.