Synthesis of the ZrC whiskers and the ablation mechanism of the ZrC whisker-toughened ZrC coating

The ZrC coatings toughened by ZrC whiskers with different microstructures were prepared on C/C composites by chemical vapor deposition (CVD). The formation mechanisms of the different morphologies of ZrC whiskers were investigated. The mechanical properties and the ablation properties under oxyacetylene flame of ZrC coatings were evaluated. The results showed that the introduction of ZrC whiskers significantly improved the adhesion to the C/C substrate and elastic modulus of ZrC coatings. The coatings exhibited a denser oxide layer after ablation than before ZrC whiskers addition due to the forming of the ZrO₂ skeleton structure, which provides a solid support to oxide layers. The linear ablation rate of the coating (−0.233 μm/s) decreased by 58.91 % compared to the pure ZrC coating (−0.567 μm/s). Following detailed observation and characterization, a potential protective mechanism for ZrC whiskers was presented.