不同纤维预制体结构对SiCf/PyC/SiBCN复合材料力学性能的影响

摘要

使用不同织造方式(二维机织,法向增强2.5维机织和三维五向编织)制备了3种SiC纤维预制体,采用树脂转移模塑(RTM)和聚合物浸渍裂解(PIP)工艺制备了SiCf/PyC/SiBCN复合材料.观察复合材料的显微组织,测试弯曲强度、拉伸强度、压缩强度等力学性能,探究不同预制体结构对复合材料力学性能的影响行为.结果表明:同一预制体结构在不同方向的纤维分布不同导致材料力学性能的各向异性;不同预制体结构对材料力学性能有着显著的影响.%Three continuous silicon carbide fiber reinforced SiBCN composites (SiCf/PyC/SiBCN) distinguished by different weaving methods of fibers (including two dimensional woven, 2.5 dimensional woven with the fiber tow through the thickness and three dimensional five directional braiding) were fabricated by resin transfer molding (RTM), polymer impregnation and pyrolysis (PIP) technology.In order to study the impact of waving methods, the microstructures of fabricated composites were observed and the mechanical properties such as tensile, compression strength and bending strength of the composites were tested.The results show that different distributions of fibers on different directions lead to anisotropy of mechanical properties for each composite, and fabric preform structure has a significant influence on the mechanical properties of the composites.