C/C基体上ZrB_(2)/SiC复合涂层的抗烧蚀性增强方法

Anti-Ablative Performance Enhancement Method for ZrB_(2)/SiC Composite Coatings on C/C Matrix

研究高压热流场景下,在碳/碳(C/C)基体表面ZrB_(2)/SiC复合涂层的抗烧蚀性增强方法.在等离子体喷涂ZrB_(2)/SiC复合涂层表面,采用CH3SiCl3-H2-Ar系统,化学气相沉积(CVD)-SiC密封层.对ZrB_(2)/SiC涂层与CVD-SiC密封层的结构演化、烧蚀性能与烧蚀机理进行了研究.结果表明:CVD-SiC密封层增强的ZrB_(2)/SiC复合涂层经过两个600 s循环烧蚀后,仍然具备抗烧蚀性能,表面CVD-SiC由β相向α相转化.CVD-SiC密封层填充了等离子喷涂ZrB_(2)/SiC复合涂层的空隙,限制了氧沿着涂层裂纹和孔洞向C/C基体扩散,进而提高了抗烧蚀性.

To improve the anti-ablative performance under high pressure heat fluxes environment,an enhancement method was presented for ZrB_(2)/SiC composite coatings on the C/C matrix.It was arranged like that,taking the chemical vapor deposition as the preparation method of sealing layer(CVD)–SiC on the plasma spraying ZrB_(2)/SiC composite coatings and taking the CH3SiCl3–H2–Ar as a deposition system.Based on this condition,the structure evolution of the ZrB_(2)/SiC composite coatings with CVD–SiC sealing layer and ablation property and ablation mechanism were investigated under an oxyacetylene torch environment.The results show that after two 600 s cycles ablation,the ZrB_(2)/SiC composite coating enhanced by the CVD–SiC sealing layer still possesses the ablative resistance and the surface of CVD–SiC shows a transformation fromβtoαphase.CVD–SiC layer is filled with the gap of plasma spraying ZrB_(2)/SiC composite coatings,the sealing layer can restrict the oxygen diffusion to the C/C matrix along cracks and holes in the coatings,thereby improving the ablative resistance.