Influence of SiC molar ratio on ablation resistance in TaC-ZrC-SiC multi-component composite coatings

Three kinds of spraying powders with different mole ratio: #3 (TaC:ZrC:SiC = 0.6:1.2:3), #2 (TaC:ZrC:SiC = 0.6:1.2:2), #1 (TaC:ZrC:SiC = 0.6:1.2:1) were prepared by spray granulation. TaC-ZrC-SiC (TZS) multicomponent composite coatings were prepared on C/C composites with SiC coating by atmospheric plasma spraying. The ablation behavior and anti-ablation mechanism of TZS multi-component composite coating were investigated by using 4.2 MW/m 2 oxyacetylene flame. After ablation, the TZS coating presents three different ablated morphologies: ablated center region, ablated transition region and ablated edge region. In the ablation edge region, a protective SiO 2 -encapsulated TaC/ZrC core-shell structure formed, while the transition region was dominated by Ta 2 Zr 6 O 17 composite oxide generated through solid-phase reaction between Ta 2 O 5 and ZrO 2 . Notably, the TZS-#3 coating exhibited no peeling in its ablation center, demonstrated the lowest mass ablation rate among the three coatings, and ultimately showed superior ablation resistance.