Effect of heat treatment on the interfacial bonding between SiC coating and alumina plate

Abstract

In this paper, the SiC coating was deposited on an alumina substrate by a radio frequency magnetron sputtering method using a-SiC (99.999%) target. The produced SiC–Al₂O₃ structure was heat treated in air through a range of temperatures. The effects of heat treatment temperature and duration on the surface roughness, interfacial bonding and surface hardness were investigated using experimental means such as optical surface profilometer, scanning electron microscope, energy dispersive X-ray analysis and hardness analyser. The results indicated that the sputtered SiC coating is an effective approach to alter the surface properties of alumina, through significantly increasing the surface roughness and hardness. Furthermore, the heat treatment did not result in decomposition of the surface coating. Appropriate heat treatment was found to improve the interfacial bonding between the sputtering material and substrate via enhanced species diffusion.