Cf／SiO2复合材料的组织性能与强韧化机理

采用真空热压烧结工艺制备了高致密的短C纤维（Cf)补强增韧SiO2基复合材料，研究了其组织结构、力学性能和强韧化机制。10％Cf/SiO2复合材料非晶态基体SiO2只发生部分晶化，Cf在基体中分布较均匀，并呈层状分布。复合材料强度、断裂韧性和断裂应变均基体显著改善，分别达到74MPa,2.4MPa.m^1/2和0．144％。压痕裂纹扩展行为和断口分析表明，Cf的桥接、拔出和诱导裂纹传转等是复合材料的强韧化机制。

Microstructure, Properties and Mechanisms of Reinforcing for Cf/SiO2 Ceramic Matrix Composite

The microstructure, mechanical properties, the mechanisms of strengthening and toughening for the 10%C f/SiO 2 composite prepared by vacuum hot pressing, were studied. The SiO 2 glass matrix crystallized partially after hot pressing. The composite has a lamellar structure with the carbon fibers in parallel with the hot pressing plane. The bending strength, fracture toughness and fracture strain of the composite are significantly improved, compared with that of the matrix. Bridging and pulling out of carbon fibers and crabon fibers and crack deflection induced by the carbon fibers are the principal mechanisms of strengthening and toughening.