Multi-component solid solutions with non-stoichiometric compositions are characteristics of ultra-high temperature carbides as promising materials for hypersonic vehicles. However, for group IV transition-metal carbides, the oxidation behavior of multi-component non-stoichiometric (Zr,Hf,Ti)C_x carbide solid solution has not been clarified yet. The present work fabricated four kinds of (Zr,Hf,Ti)C_x carbide solid solution powders by free-pressureless spark plasma sintering to investigate the oxidation behavior of (Zr,Hf,Ti)C_x in air. The effects of metallic atom composition on oxidation resistance were examined. The results indicate that the oxidation kinetics of (Zr,Hf,Ti)C_x are composition dependent. A high Hf content in (Zr,Hf,Ti)C_x was beneficial to form an amorphous Zr-Hf-Ti-C-O oxycarbide layer as an oxygen barrier to enhance the initial oxidation resistance. Meanwhile, an equiatomic ratio of metallic atoms reduced the growth rate of (Zr,Hf,Ti)O₂ oxide, increasing its phase stability at high temperatures, which improved the oxidation activation energy of (Zr, Hf, Ti)C_x.

具有非化学计量成分的多组分固溶体是超高温碳化物作为高超音速飞行器有前途的材料的特征。然而，对于IV族过渡金属碳化物，多组分非化学计量(Zr,Hf,Ti)C _x碳化物固溶体的氧化行为尚未阐明。本工作采用无压放电等离子烧结法制备了四种(Zr,Hf,Ti)C _x碳化物固溶体粉末，研究了(Zr,Hf,Ti)C _x在空气中的氧化行为。研究了金属原子组成对抗氧化性的影响。结果表明，(Zr,Hf,Ti)C _x的氧化动力学与成分有关。(Zr,Hf,Ti)C 中 Hf 含量高_x有利于形成无定形 Zr-Hf-Ti-CO 碳氧化物层作为氧屏障以增强初始抗氧化性。同时，金属原子的等原子比降低了(Zr,Hf,Ti)O ₂氧化物的生长速率，增加了其高温相稳定性，从而提高了(Zr, Hf, Ti)C _x的氧化活化能。