Influence of the Edge Effect on the Tribological Behavior of textured Si-DLC Films under Oil Lubrication

Edge effect causing stress concentration at the texture edges is an important factor affecting the tribological properties of textured materials. By laser ablation, electrochemical and mechanical polishing, a series of normal and edge-profiled dimple textures were prepared on stainless steel substrates. Si-DLC films were deposited on the substrates via sputtering and RF-CVD method to obtain the untextured, the normal and edge-profiled textured Si-DLC films, and the edge-profiling effect on the tribological performance under oil lubrication of the textured Si-DLC films was investigated. The contact stress distribution of the textures was analyzed by the finite element method to discuss the changes in edge effect due to edge-profiling. The results show that by edge-profiling, the friction of the textured Si-DLC films and the wear of the mated balls, as well as the maximum contact stress concentrated at the edge of the textures were reduced markedly. The tribological properties of the textures were positively related to the edge effect. The reduction of the maximum stress was thought to play an important role in lowering the friction and wear.