Advances in Material Science

This study investigates the effect of the Si/Zr mass ratio on the morphology, phase composition, and anti-ablation performance of Si-Zr-C composite coatings on C/C composite materials by controlling the Si/Zr mass ratio in the infiltration material. With an increase in the Si/Zr mass ratio in the infiltration material, the coating becomes smoother, and there are changes in the phase composition of the coating. Through ablation testing, it was observed that the anti-ablation performance of the coating initially increases and then decreases with an increase in the Si/Zr mass ratio. The best anti-ablation performance is exhibited when the Si/Zr mass ratio is 6:4, with a mass ablation rate of -3.083×10-5/ g·s-1 after 120s of ablation. The presence of fewer cracks and grain boundaries on the coating surface results in higher coating strength. Additionally, the reaction products ZrO2 and ZrSiO4 enhance the high-temperature stability of SiO2. Moreover, they themselves possess good anti-ablation performance and a lower oxygen diffusion rate, thereby improving the anti-ablation performance of the coating.