LAUSR

Abstract A dense structure and well-bonded Si-SiC coating was fabricated by impregnation-pyrolysis combined with gaseous silicon infiltration to protect graphite materials from oxidation and ablation. The phase synthesis, microstructure, anti-oxidation and anti-ablation properties of the obtained Si-SiC coating were studied. Results indicated that the Si-SiC coating was defect-free, and SiC particles were surrounded by residual silicon. The prepared coating can withstand 300 h, 468 h, 223 h and 223 h of isothermal static oxidation at 800 °C, 1000 °C, 1300 °C and 1500 °C, respectively, which was considered to be the dense structure of coating and glassy SiO2 film formed on the coating surface. The coated sample presented good ablation resistance performance, after ablation for 90 s, the mass and linear ablation rates of Si-SiC coated sample were 0.13 mg/s and 0.02 µm/s, respectively. Thermal physical and chemical erosion along with thermos-mechanical denudation of the Si-SiC coating are responsible for the ablation behaviors of the Si-SiC coating.