Abstract

Surface textured diamond-like carbon (DLC) films with Ti and Al dopants (Ti/Al-DLC) were fabricated by a two-step process, including the photo- and anisotropic-etching of silicon substrate for micro-dimple texturing and the hybrid ion beam deposition for Ti/Al-DLC film. The role of different dimple-textured area densities (0~40%) on the tribological behavior of Ti/Al-DLC film was mainly investigated; the corresponding surface topographies and atomic bond structure of intrinsic films, wear tracks, and wear scars were evaluated systematically to disclose the fundamental mechanism. Results revealed that the dimple-textured structure on film surface had a significant effect on the tribological property of Ti/Al-DLC film rather than the microstructure and mechanical performances. Compared to the untextured Ti/Al-DLC film, the case with dimple-textured area density of 5% exhibited the reduction in coefficient of friction by 17.8% and in wear rate by 44.5%, respectively. This attributed to the synergistic effect of the tribo-induced graphitization and the capturing efficiency of micro-dimples to the wear particles. However, with further increasing the textured area density from 5% to 40%, the locally high contact pressure resulted in the lack of graphitization and the increase of roughness at the friction interface, which prohibited the sliding of friction interface following the weakened tribological property.