Cl2 Corrosion Resistance of Sic Coatings with Different Morphologies

Abstract

The objective of this study was to investigate the corrosion resistance of SiC coatings with different morphologies on graphite in a high-temperature Cl2 environment. The researchers conducted a detailed assessment of the coating's corrosion resistance by comparing micro-morphology, surface roughness changes, and mass loss rates before and after corrosion. The findings reveal that the SiC layer can undergo chemical reaction with Cl2 at high temperatures, leading to the formation of layered or granular carbon on the grain surface. Corrosion predominantly occurs at the grain boundaries. Among the samples tested, the S30 sample, characterized by the smallest grain size, demonstrates the highest corrosion resistance. It exhibits a low mass loss rate of only 0.72% and a minimal surface roughness change rate of 11.3% before and after corrosion.

Keywords: Cl2 Corrosion, Chemical Vapor Deposition, SiC coating, Crystallite morphology