effect of cu content on tin-cu nanocomposite film properties: structural and hardness studies

titanium nitride-copper (tin-cu) nanocomposite films were deposited onto stainless steel substrate using hollow cathode discharge ion plating technique. the influence of cu content in the range of 2-7 at.% on the microstructure, morphology and mechanical properties of deposited films were investigated. structural properties of the films were studied by x-ray diffraction pattern. topography of the deposited films was studied using atomic force microscopy. film hardness was estimated by a triboscope nanoindentation system. however, x-ray photoelectron spectroscopy analysis was performed to study the surface chemical bonding states. it was found that addition of soft cu phase above 2 at.% to tin film drastically decreased the film hardness from 30 to 2.8 gpa due to lubricant effect of segregated copper particles. x-ray photoelectron spectroscopy results showed that cu and tin phases grew separately. in our case,the formation of a solid solution or chemical bonding between cu and ti was rejected.