连续碳纤维增强碳化硅复合材料的制备与性能研究

Preparation and Properties of Continuous Carbon Fiber-Reinforced Silicon Carbide Composites

利用自加热化学气相渗积法制备了连续碳纤维增强的碳化硅陶瓷基复合材料 ,分析研究了复合材料致密度和涂层厚度对复合材料力学性能的影响 ,同时运用 SEM对复合材料的微观结构进行了表征 .研究结果表明 :随着致密度的提高 ,复合材料的力学性能有了明显改善 ,密度为 1.93g/ cm3时 ,弯曲强度达到 382 .2 MPa,断裂韧性达到 9.2 MPa· m1 /2 ;碳涂层的厚度对复合材料的力学性能有较大影响 ,涂层厚度在 0 .35μm时 ,弯曲强度达到2 31.9MPa,在 0 .5 5μm时 ,断裂韧性达到 10 .4 MPa· m1 /2 .

C f/SiC composites were fabricated by self heating chemical vapor infiltration, and their mechanical properties and microstructure were investigated. Effects of the densification of the composites and carbon coating thickness on the mechanical properties of the composites were studied. The following observations were made: mechanical properties of the composites increased as the densification increased. When the density was 1 93 g/cm 3, the flexural strength and fracture toughness were 382 2 MPa and 9 2 MPa·m 1/2 respectively. Carbon coating thickness has evident effects on the mechanical properties of the composites. When the carbon coating thickness was 0 35 μm, the flexural strength was 231 9 MPa. When the carbon coating thickness was 0 55 μm, the fracture toughness was 10 4 MPa·m 1/2 .