Optimizing and ablation behavior of ZrC-SiC coating prepared by a coupling process

Abstract

A new route was proposed to fabricate ZrC-SiC coatings on carbon/carbon composites by slurry dipping and chemical vapor reaction methods. The cyclic ablation resistance of the coatings with different thicknesses was investigated using an oxyacetylene torch. During cyclic ablation, a moderate coating thickness can help relieve the residual thermal stress, decreasing the generation of cracks. In addition, the ZrO₂ skeleton pinned the SiO₂ glass and the molten Zr-Si-O glass that can work as a protective layer against ablation, and its anti-ablation behavior changed from “surface ablation” to “internal ablation” with increasing ablation time and cycles. After ablation for 180 s (2 cycles, 90 s for each), the ZrC-SiC coating with a thickness about 220 μm exhibited the best cyclic ablation resistance with the mass and linear ablation rates of 0.40 × 10⁻³ mg/s·mm² and − 0.39 μm/s, respectively.