Cl2 corrosion resistance of SiC coatings with different morphologies

The objective of this study was to investigate the corrosion resistance of SiC coatings with various morphologies on graphite in a high-temperature Cl2 environment. The researchers conducted a thorough assessment of the coating's corrosion resistance by comparing micro-morphology, changes in surface roughness, and mass loss rates before and after corrosion. The findings reveal that the SiC layer can undergo a chemical reaction with Cl2 at high temperatures, resulting in the formation of layered or granular carbon on the grain surface. Corrosion occurs primarily at the grain boundaries. Among the tested samples, the S30 sample, characterized by the smallest grain size with average grain size 7.15μm, exhibited the highest corrosion resistance. It showed a low mass loss rate of only 0.72 % and a minimal surface roughness change rate of 11.3 % before and after corrosion, whereas the S40 exhibited the highest mass rate loss of 1.2 % and S20 had the highest roughness variation rate 54.3 %. [Display omitted]