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采用先驱体浸渍裂解结合液硅渗透的方法制备C/C-SiC复合材料。通过X射线衍射和扫描电镜分析了材料的成分和微结构,采用压缩双切口试样法分别在室温和1600℃下测试其层间剪切强度,分析了微观剪切破坏机理。结果表明:碳纤维表面的热解碳(PyC)与液硅反应生成一层SiC,保护纤维不受残余Si的损伤。树脂碳和液硅反应生成的SiC填充了多孔C/C的孔隙。材料的高温层间剪切强度是室温下的2倍左右。室温下基体存在残余热应力,界面结合强度低,材料属于脆性断裂,高温下基体残余热应力得到释放,界面结合强度增大,基体裂纹部分闭合,该复合材料可承受更大的剪切应力。
C / C-SiC composites were prepared by impregnation of precursor and immersion in liquid silicon. The composition and microstructure of the material were analyzed by X-ray diffraction and scanning electron microscopy. The interlaminar shear strength was tested at room temperature and 1600 ℃ using the double-cut specimen method. The mechanism of microscopic shear failure was analyzed. The results show that PyC on the surface of carbon fiber reacts with liquid silicon to form a layer of SiC, which protects the fiber from residual Si. The SiC formed by the reaction between the resin carbon and the liquid silicon fills the pores of the porous C / C. The material’s high temperature interlaminar shear strength is about 2 times the room temperature. The matrix has residual thermal stress at room temperature, the bonding strength is low, the material is brittle fracture, the residual thermal stress is released at high temperature, the interfacial bonding strength is increased, and the matrix crack is partially closed. The composite can withstand greater shear stress.