Ag-doped CrN coating towards exhibiting excellent tribological and electrical properties under current-carrying friction

In order to obtain sliding electrical contact materials with good conductivity and wear resistance, a series of silver doped chromium nitride (CrN-Ag) coatings were prepared by magnetron sputtering. The hardness, elastic modulus, chemical composition and surface morphology of the prepared coatings were characterized in detail. The tribological properties and conductivities of the prepared CrN-Ag coatings were investigated in detail at low and high current densities. The worn surfaces after friction test were also investigated to explore the lubrication mechanisms. The results show that the addition of Ag element could regulate the hardness, elastic modulus, chemical composition and surface morphology of the coatings. The CrN-Ag coating with 23 wt% Ag content exhibited the best conductive and tribological properties under low and high current densities. The analysis of friction surface shows that the conductivity and wear resistance of different coatings were mainly related to the Ag content of coatings.