The effects of carbon/carbon composites blasting treatment and modifying SiC coatings with SiC/ZrB2 on their oxidation and cyclic ablation performances

To enhance the oxidation and ablation performances of SiC coating, C/C composites with a porous surface layer were designed via blasting treatment and then followed by ZrB2 additive in the process of pressure-less reactive sintering. Cyclic ablation test using oxyacetylene torch from 1750 degrees C to room temperature showed that the coating possessed good ablation performance accompanying with the formation of Zr-O-Si glassy protective layer. The good sintering performance combined with the increased coating/substrate interfaces contributed to reduce the cyclic thermal stress and enhance the stability of the Zr-O-Si layer to the denudation of oxyacetylene torch, thus promoting the ablation performance.