Optimization of sputter-deposited corrosion resistant a-C(:H) films with excellent tribological performance by control of methane flow rate

Abstract

To meet the lubrication demand in the maritime sector, hydrogenated amorphous carbon (a-C:H) films with low friction coefficient and excellent corrosion resistance were deposited at different methane flow rates by control sputtering technique. Studies have shown that the increment of CH4 flow rate raised the growth rate and compactness of a-C(:H) films while decreased the hardness, the adhesion force was enhanced. The film had the best tribological performance at 5 sccm CH4 gas flow rate, with a friction coefficient of about 0.1 (in air) / 0.04 (in salt solution) and a wear rate of 1.0 × 10−9 mm3/Nm / 6.2 × 10−8 mm3/Nm. With increasing CH4 flow rate, the corrosion resistance of the films improved. And 10 sccm was the optimal for the comprehensive performance of the film.