Abstract Ablation behavior and thermal damage mechanisms of Cf/SiBCN composites were investigated in plasma ablation flame under a heat flux of 4.02 MW/m2, simulating a hypersonic service environment at ∼2200 °C. Oxide layer formed on the composites surface effectively protects internal Cf/SiBCN composites from further ablation. However, the internal Cf/SiBCN composites endure severe thermal damage and complex reactions, leading to decomposition of SiBCN matrix and formation of α/β-SiC, β-Si3N4 grains, amorphous C layer and ring-like SiC layer. Based on detailed microstructure and phase composition analysis, thermal damage and microstructure evolution mechanisms of Cf/SiBCN composites during plasma ablation are clarified.

中文翻译：

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Cf/SiBCN复合材料在等离子体烧蚀过程中的热损伤和微观结构演化机制

摘要 在热通量为 4.02 MW/m2 的等离子体烧蚀火焰中研究了 Cf/SiBCN 复合材料的烧蚀行为和热损伤机制，模拟了 2200 °C 的高超声速服务环境。在复合材料表面形成的氧化层有效地保护内部 Cf/SiBCN 复合材料免受进一步烧蚀。然而，内部的 Cf/SiBCN 复合材料经受严重的热损伤和复杂的反应，导致 SiBCN 基体分解并形成 α/β-SiC、β-Si3N4 晶粒、非晶 C 层和环状 SiC 层。基于详细的微观结构和相组成分析，阐明了 Cf/SiBCN 复合材料在等离子体烧蚀过程中的热损伤和微观结构演化机制。