Korean Source SiOC Korean Source

To improve the chemical stability of metal, the ceramic coatings on metallic materials have attracted interest from many researchers due to the chemical inertness of ceramic materials. To endure strong acids, SiOC coating on metal substrate was carried out by dip coating method using 20wt% polyphenylcarbosilane solution; SiC powder was added to the solution at 10wt% and 15wt% to improve the mechanical properties and to prevent cracks of the film. Thermal oxidation as a curing step was carried out at 200°C for crosslinking of the polyphenylcarbosilane, and the coating samples were pyrolysized at 800°C under argon to convert the polyphenylcarbosilane to SiOC film. The thicknesses of the SiOC coating films were 2.36 μm and 3.16 μm. The quantities of each element were measured as SiO_1.07C_6.33 by EPMA, and it can be confirmed that the SiOC film from polyphenylcarbosilane was formed in a manner that was carbon rich. The hardness of the SiOC film was found to be 3.2Gpa through nanoindentor measurement. No defect including cracks appeared in the SiOC film. The weight loss of the SiOC coated stainless steel was within 2% after soaking in 10% HCl solution at 80°C for one week. From these results, SiOC coating shows good potential for application to protect against severe chemical corrosion of stainless steel.