制备工艺对碳纤维增强碳化硅基复合材料结构和力学性能的影响

Effect of Preparation Technique on Microstructure and Mechanical Properties of Carbon Fiber Reinforced Silicon Carbide Matrix Composites

以化学气相沉积碳为界面层,聚碳硅烷为先驱体,经过10个周期的浸渍-裂解制备了三维编织碳纤维增强碳化硅复合材料(3D-Cf/SiC)。考察了碳涂层高温预处理和陶瓷先驱体第一个周期1600℃裂解对复合材料结构与性能的影响。结果表明:碳涂层高温预处理有助于复合材料密度的提高,弱化了复合材料的界面结合,从而显著提高了复合材料的力学性能,复合材料弯曲强度达到571 MPa,剪切强度51 MPa,断裂韧性18 MPa.m1/2。

Three-dimensional braided carbon fiber reinforced silicon carbide（3D-BCf/SiC） composites were prepared through ten cycles of precursor infiltration and pyrolysis（PIP）, with carbon coatings prepared by chemical vapor deposition （CVD） before PIP. The influences of 1600℃ heat treatment and the first cycle of PIP with 1600℃ pyrolysis on the microstructure and mechanical properties of Cf/SiC composites were discussed. It is found that heat treatment before PIPhas great effect on the mechanical properties of Cf/SiC composites. After first cycle of heat treatment, the density of composites increases, the interfacial bonding is weakened, so the properties of Cf/SiC composites are improved. The flexual strength of the Cf/SiC composites with heat treatment reaches 571 MPa, shear strength 51 MPa and fracture toughness 18 MPa·m^1/2