Abstract:Silver lubrication coatings of 8 μm in thickness were prepared on the surface of 718 alloy by magnetron sputtering.The phases and surface morphology of the coatings were observed by XRD,and the friction and wear properties were investigated experimentally under low temperatures and vacuum conditions.The worn surfaces of silver coatings were measured with SEMEDS to study the mechanisms of friction and transfer film lubrication in different experiment conditions.It is found that the surface of silver coating has fine grain and high density,there is a good binding properties between the coating and the substrate,and the size of silver coating is about 200 nm.The silver coatings show promising lubrication roles in experiment conditions,the furrow marks are appeared at polishing scratches and the wear mechanism is abrasive and adhesive wear at 25 ℃.The cracks and holes are observed on the local area of polishing scratches coating at 0 ℃.The silver coatings present the optimal friction and wear properties at -50 ℃,a minimum friction coefficient and wear loss are determined,and the wear mechanism is slight abrasive wear.The furrow marks are appeared again,and the wear mechanism is peeling and brittle fracture at -100 ℃.