Ablation characteristics of mosaic structure ZrC-SiC coatings on low-density, porous C/C composites

Mosaic structure ZrC-SiC coatings were fabricated on low-density, porous C/C composites via thermal evaporation and an in-situ method. ZrC was packed in a typical lamellar mode, and the mosaic structure was formed by the deposition of Zr and Si atoms on the shallow surface of the porous C/C composites. Ablation analysis showed that the defects in the coatings originate from the boundary between the ZrC and holes created by the consumption of SiC at 2500 degrees C. After ablation for 200 sat 3000 degrees C, a dense ZrO2 layer formed on the coating surface, and the defects were sealed owing to the continuous supply of ablative components. The mass and line ablation rates of the ZrC-SiC coatings were -0.46 +/- 0.15 mg cm(-2).s(-1) and -1.00 +/- 0.04 mu m s(-1), respectively. (C) 2019 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.