ZrSiO4 Oxidation Protective Coating for SiC-Coated Carbon/Carbon Composites Prepared by Supersonic Plasma Spraying

To protect carbon/carbon (C/C) composites against oxidation, ZrSiO4 oxidation protective coating was prepared on SiC-coated C/C composites by supersonic plasma spraying. X-ray diffraction and scanning electron microscopy were used to analyze the phase and microstructure of the coating. The results show that the as-prepared ZrSiO4 coating is continuous and well bonded with the SiC inner layer without penetrating crack, which exhibits good oxidation-resistant properties. After oxidation at 1773 K in air for 97 h and nine thermal shock cycles between 1773 K and room temperature, the weight loss of the coated C/C composites was only 0.08%. The excellent oxidation-resistant properties of the coating were attributed to its dense structure and the formation of the stable ZrO2-SiO2 glassy mixture on the surface of ZrSiO4 coating.