Influence of TaSi₂/WSi₂ doping on the ablation behavior of ZrB₂-SiC-MoSi₂ ultra-high temperature ceramic composites

Hypersonic vehicles encounter thermal environments spanning distinct temperature regimes, which places higher demands on the thermal protection system. In this study, ZrB₂-SiC-MoSi₂ composites incorporated with TaSi₂ or WSi₂ were prepared by spark plasma sintering; and their ablation resistance behaviors were investigated under an oxyacetylene flame at 1800°C. ZrB₂-SiC-MoSi₂ composite exhibited the minimum oxide layer thickness among the four compositions tested, confirming the positive effect of silicide addition on the oxidation resistance performance. Consequently, with dual-transition-metal silicide alloying of MoSi₂ and TaSi₂, TaSi₂ oxidised preferentially to Ta₂O₅ and TaZr_2.75O₈, consumed oxygen, eliminated the SiC-depleted zone and raised the viscosity of the borosilicate glass. Our findings offer fundamental insights into the influence of dual-transition-metal silicide alloying on the performance of ultra-high temperature ceramic composites, promoting their engineering applications for future hypersonic vehicles.