Tribological properties of SiC coatings deposited by r.f. magnetron sputtering with change in substrate temperature

Abstract

Silicon carbide coatings have been deposited by r.f. magnetron sputtering on AISI 304LN stainless steel at four different substrate temperatures. At the lowest substrate temperature of 300°C, the film was amorphous whereas at a substrate temperature of 600°C a crystalline SiC phase was obtained. However, at substrate temperature of 800°C, the films were amorphous again. The tribological properties of the coatings were also found to change with substrate temperature. The coefficient of friction was found to be low for the crystalline films. Such a low value of coefficient of friction is indicative of superior wear resistance. A higher coating thickness enhanced the tribological properties while any surface roughness of the substrate and coating was found to degrade these properties. Micro-Raman spectra of the films varied with substrate temperature. Some phases were found to disappear and new phases were observed in the wear track with progressive sliding.