The influence of textured interface on DLC films prepared by vacuum arc

Abstract

Vacuum arc was used to prepare Cr/CrN/DLC films on different textured surfaces fabricated by femto-laser, and the influences of textures with different patterns, sizes, and orientations on structures, adhesion and mechanical properties of Cr/CrN/DLC films were investigated. The physical and chemical characteristics of DLC films were studied by scanning electron microscopy (SEM), Raman. Morphology instrument was used to test the chemical structure and surface topography. Adhesive strength and anti-wear properties were measured by scratch tester and SRV micro-tester. The results showed that micro-structures improve the contents of sp3 in DLC film, and also affect the adhesive strength and anti-wear properties of DLC films by increasing interval from 150 to 350 μm, which was processed by femto-laser under 0.96 power density, 400 mm/min processing speed. The experiment certificated that DLC film on stripe structure with 250–350 μm interval showed best properties, the wear rate of DLC film with 250 μm interval was lower than 1.35 × 10−6 mm3/Nm, and the adhesion strength of film was up to 52 N on stripe micro-structure separated around 350 μm. The results showed that femto-second ultrafast laser has little influence on substrate, the textured surface improved the sp3 contents in DLC films with suitable size. Compared to the DLC film without micro-structure, the best anti-wear properties of DLC film with textured interface with 250 μm interval were enhanced up to 50 times.