Plasma ablation behavior of Yb₂O₃ modified C/C-Hf_1-xZr_xC composites

C/C-Hf_1-xZr_xC composites were fabricated via the precursor infiltration and pyrolysis (PIP) process, with varying Yb₂O₃ concentrations. In this study, the ablation behaviour of modified ceramic composites in a plasma flame was systematically investigated, and their corresponding. Through analysis of the post-ablation morphology and microstructure, the corresponding microstructural evolution was analysed. During the ablation test, the modified components were preferentially oxidized to generate a Hf-Zr-Yb-O oxide barrier layer, which effectively mitigated the thermal oxidation damage. Additionally, the addition of Yb₂O₃ stabilizes the high temperature phase of HfO₂/ZrO₂ and enhances the integrity of the oxide layer by minimizing spalling caused by structural stress. At high temperatures, Yb₂O₃ reacts with HfO₂/ZrO₂ to form the refractory phases Yb₂Zr₂O₇ and Yb₂Hf₂O₇. These newly formed phases demonstrate excellent thermal stability, surpassing that of HfO₂/ZrO₂, thereby promoting improved ablation performance through both physical shielding and chemical stabilization effects.