2020 Volume 59 Issue 1 Pages 270-275
This study is aimed at clarifying the factors that affect the properties of Ag–Nano C composite films on Cu alloys as automotive connectors. The content of Nano C in Ag matrix was mainly dependent on current density and stirring strength during electroplating. The hardness of Ag–Nano C composite films increased 13–58% compared to pure Ag film depending on stirring intensity. Especially, it was found in wear tests that the inclusion of Nano C in Ag films inhibited effectively the adhesive phenomenon at the early stage, and delivered lower friction coefficient at stable region, thus producing less worn volume than that of pure Ag film. Moreover, the observation of tribofilms on plate specimens after wear tests indicates that the Ag–Nano C composite films exhibited an abrasive wear mode with smooth wear tracks, whereas the pure Ag films delivered normally an adhesive wear mode with a coarse wear track. The enhancement on wear resistance of Ag–Nano C composite films can be mainly attributed to the excellent lubrication of Nano C as graphene in Ag matrix film during friction, which included in wear powder between the connectors, thus maintaining both the lubrication and the electric contact resistance.
