The self-lubricating behavior and evolution mechanisms of the surface microporous friction interface of M50-(Sn-Ag-Cu) material

Abstract

The friction interface structure has an important influence on the friction behavior of self-lubricating materials. In this paper, M50 material covered with surface micropores filled with Sn-Ag-Cu (MM-Salloy) was prepared by laser melt deposition. From 25–450 °C, the friction test results show that MM-Salloy exhibits distinguished tribological properties due to the existence of the microporous friction interface. Analysis indicates that Sn-Ag-Cu in surface micropores can dynamically precipitates to the worn surface of MM-Salloy to achieve a lubricating effect, and the increasing of temperature is beneficial to the dynamic precipitation of Sn-Ag-Cu. The whole friction process can be divided into the initial wear stage, fast wear stage and stable wear stage. At stable wear stage, the friction interface is mainly composed of a lubricant-rich surface lubrication layer and a subsurface load-bearing layer, which greatly improves the material's wear resistance. Especially at 350 °C, the surface lubrication layer and subsurface load-bearing layer are most easily formed.