2DC_f/SiC-Si复合材料的制备和性能研究

Study on the Fabrication and Properties of the 2D C_f/SiC-Si Composites

针对短时高温抗氧化的具体环境,采用先驱体转化工艺制备2D Cf/SiC-Si复合材料。首先考察首周期裂解温度对2D Cf/SiC-Si材料力学性能的影响,结果表明,首周期采用1200℃裂解,所制备的2D Cf/SiC-Si复合材料界面结合较好,弯曲强度和断裂韧性分别达到305.4MPa和15.7 MPa.m1/2。在此基础上研究了Si粉含量对材料性能的影响。结果表明,随着Si含量的增加,2D Cf/SiC-Si材料的力学性能稍有降低,而抗氧化性能明显提高,主要原因在于材料中游离碳含量的降低和Si氧化后生成的具有封填裂纹和隔氧作用的SiO2膜。

Based on the high temperature and short-term oxidation environments, 2D Cf/SiC-Si composites were prepared by precursor infiltration and pyrolysis. Effects of the pyrolysis temperature at the first cycle and Si content on the mechanical properties and anti-oxidation properties were investigated. The results showed that 2D C/SiC-Si composites exhibited weak interface bonding and better mechanical properties when the pyrolysis temperature of the first cycle was 1200℃ , and the flexural strength and fracture toughness reached 305.4MPa and 15.7MPa - m^（1/2） , respectively. At the same time, with the increase of the Si content, the mechanical properties of the composites decreased slightly, while the anti-oxidation properties of the composites were remarkably improved. The better antioxidation properties of the composites were attributed to the decrease of the free carbon in the composites and Si could transfer to SiO2 at high temperature in air which could heal the crack and prevent the diffusion of the oxygen.