采用液相浸渍法结合反应熔渗法快速制备改性 C ／C 复合材料，研究其微观组织及在氧乙炔焰和高频等离子体风洞环境中的烧蚀行为。结果表明：改性 C ／C 复合材料主要含有 HfC，ZrC，TaC 等高熔点陶瓷改性相，其密度为3．83 g／cm3，开孔率仅为4．71％。氧乙炔焰烧蚀360 s 后，改性 C ／C 复合材料表面形成一层主要由 HfO2，ZrO2，Ta2 O5组成的致密氧化物层，材料的线烧蚀率为0．00518 mm／s。使用高频等离子体风洞考核改性 C ／C 复合材料球头模型，在热流量3．5 MW／m2、驻点温度2293℃的条件下考核180 s 后，模型表面生成致密光滑的氧化物保护层，与基体结合牢固，模型形状及尺寸无明显改变，去掉氧化物后测得其线烧蚀率为0．00172 mm／s。%The modified C /C composite was quickly prepared by the approach of liquid impregnation combined with reactive melt infiltration. The microstructure was studied and the ablation behavior exposed under oxyacetylene flame and high-frequency plasma wind tunnel atmosphere was assessed.Results show that many high melting point refractory compounds such as HfC,ZrC,TaC are introduced into the modified C /C composite, the density and open porosity of which are 3.83 g/cm3 and 4.71%,respectively.A compact oxide film generates upon the modified C /C composite after oxyacetylene flame ablated 360 s,which is mainly composed of HfO2 ,ZrO2 and Ta2 O5 .The linear ablation rate of modified C /C composite is 0.005 18 mm /s.The ablation resistance of modified C /C composite bulb model is assessed by high-frequency plasma wind tunnel,the heat flux is 3.53 MW/m2 ,the stagnation temperature is 2293 ℃,and the test duration is 180s.After ablation,a dense oxide protective layer forms on the surface of the model,the shape and the dimension of the model are changed insignificantly,and the linear ablation rate is 0.001 72 mm /s after removing the oxide layer.
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