The tribological properties and mechanism of wear of Cu-based sintered powder materials containing molybdenum disulfide and molybdenum diselenite under unlubricated sliding against copper

► Incorporation of MoS2 and MoSe2 into copper prevents scuffing of surfaces at dry sliding against copper. ► Powdery particles of solid lubricant create the lubrication effect. ► The transfer of the composite materials to the Cu counterface initiates the substantial wear. ► Material removal is a result of adhesion between sliding materials and the transferred material on counterface. ► Lubricating effect of the solid lubricants is more pronounced at concentrations greater than 5 wt%.