Effect of Si, Al2O3 additives on the ablation behavior of ZrB2-SiC coating with Al2O3-modified SiC bond coat for C/C composites

This work firstly evaluated the effect of temperature on the preparation of SiC coating using Al2O3 as catalyst by pack cementation (PC) method. SiC/ZrB2-SiC-Si (ZSS) and SiC/ZrB2-SiC-Al2O3 (ZSA) coating were prepared on the surface of C/C composites by PC combined with atmospheric plasma spraying (APS). The objective of this work is to study the influence of Si and Al2O3 additives for ablation performances of ZrB2-SiC coating. The coated samples were subjected to ablation test, and the phase composition and microstructure evolution were investi-gated. The results indicated that SiC/ZSA coating had better ablation resistance because phase transformation and growth of ZrO2 grain was restrained by Al2O3.