论文部分内容阅读
分别采用先驱体裂解 -热压和先驱体浸渍 -裂解方法制备出了 Cf/Si C复合材料。重点探讨了不同制备工艺对复合材料纤维 /基体间界面和力学性能的影响。研究表明 ,采用先驱体裂解 -热压工艺制备复合材料时 ,由于制备温度较高 ,复合材料中纤维与基体间的界面结合强 ,同时纤维本身性能的退化严重 ,因此复合材料表现为脆性断裂 ,具有较低的力学性能。而采用先驱体浸渍 -裂解法制备复合材料时 ,由于致密化温度较低 ,复合材料中纤维与基体的界面结合较弱 ,而且纤维的性能保留率较高。因此 ,纤维能够较好地发挥补强增韧作用 ,复合材料具有较好的力学性能 ,其抗弯强度和断裂韧性分别为 5 73.4 MPa和 17.2 MPa· m1 /2。
Cf / Si C composites were prepared by precursor pyrolysis, hot pressing and precursor impregnation-pyrolysis respectively. The effects of different preparation processes on the interface and mechanical properties of the composite fiber / matrix were discussed. The results show that the composites are brittle fracture due to the high preparation temperature and the strong interfacial bonding between the fibers and the matrix in the composites and the serious deterioration of the properties of the fibers. Has a lower mechanical properties. However, when the composites were prepared by the precursor impregnation-cracking method, the interfacial bonding between the fibers and the matrix in the composites was weaker due to the lower densification temperature, and the retention of the fibers was higher. Therefore, the fiber can play a better role in toughening and toughening. The composites have better mechanical properties, flexural strength and fracture toughness are 5 73.4 MPa and 17.2 MPa · m1 / 2, respectively.