Oxidation pre-treatment to improve the mechanical property and oxidation resistance of Si-Mo-Cr coated C/C composites

A transition layer with an interlocking structure was obtained at the interface between C/C composites and Si-Mo-Cr coating by oxidation pre-treatment and pack cementation process. The effects of pre-oxidation time on the microstructures, mechanical property and oxidation behavior of the coated C/C samples were investigated. After oxidation pre-treatment at 1173. K in air for 6. min, the flexural strength of the coated samples increases by 71.7% and the mass loss rate decreases by 77.4%. The improvements of the mechanical property and oxidation resistance are primarily attributed to the formation of the moderate transition layer between C/C and Si-Mo-Cr coating.