Effects of Zr/Ti ratios on the structure and ablation characteristics of (Zr,Ti) C-SiC composites

Dense (Zr,Ti)C-SiC composites containing a dual-phase solid solution were fabricated by spark plasma sintering using homemade Mg-modified multiphase ceramic powders as raw materials. The ablation behaviour suggested that the composite with a molar ratio of Zr/Ti = 3:1 exhibited the best ablation resistance, with low mass and linear ablation rates of 2.56 +/- 0.89 mg/s and 1.26 +/- 0.40 mu m/s, respectively, after ablation for 90 s under a plasma flame test at around 2300 degrees C. It is asserted that the formation of an oxide film consisting of a self-sintered ZrO2 skeleton and a high-viscosity Ti-Mg-Si-O liquid phase was responsible for the excellent ablation resistance, which has remarkable efficacy in resisting the scouring effect of ablative flames and the erosion induced by oxidizing gases on the composite matrix.