New insight into the ablation behavior of C/C-ZrC composites in a nitrogen plasma torch with a high heat flux of ∼25 MW/m2

Highlights: • Ablation behavior of C/C-ZrC composites was studied at a heat flux of ∼25 MW/m². • Linear ablation rate of the materials is improved by 44.7 % after adding 4.1 wt% ZrC. • Carbon and ZrC react with the plasma jet to form CN and ZrN, respectively. • Thermochemical ablation and mechanical breakage are main ablation mechanism. • Carbon sublimation plays a minor role in the ablation of the composites. Ablation of C/C-ZrC composites was studied at a heat flux of ∼25 MW/m² in a nitrogen plasma torch. C/C-ZrC composites with 4.1 wt% ZrC illustrate a lower linear ablation rate than other composites, that is, 44.7 % lower than that of C/C composites. The formed ZrN/ZrO₂ may decrease the ablation rate of the composites by blocking the chemical reaction of the plasma jet and carbon and absorbing significant heat from the plasma jet by their melting and evaporation. The ablation of C/C-ZrC composites is controlled by thermochemical ablation, mechanical breakage, and carbon sublimation, which plays a minor role.