多孔体制备工艺对C/C-SiC复合材料弯曲性能的影响

以针刺整体炭毡为坯体,采用CVD和树脂浸渍／炭化混合法增密制备了4种C／C多孔体,然后熔硅浸渗C／C多孔体制备了C／C-SiC复合材料;研究了不同炭涂层、高温热处理对C／C-SiC复合材料弯曲强度和断裂方式的影响。结果表明：热解炭涂层可减少制备过程中炭纤维的损伤,具有适中的界面结合强度,使复合材料的弯曲强度达到161．5MPa,表现出良好的“假塑性”;适当选择高温热处理工艺可制备弯曲性能较高,具有一定“假塑性”的C／C-SiC复合材料。

Effect of manufacturing techniques of performs on properties and fracture modes of C/C-SiC composites

Through molten silicon infiltration the C/C-SiC composites were made of the different porous C/C preforms which were prepared by the mixing of CVD and resin impregnation /carbonization with the integrity felt as preforms. The effects of different carbon coatings and high temperature treatment on the flexural strength and fracture modes of C/C-SiC composites were studied. The results show that C/C-SiC composites with pyrolytic carbon coating have higher flexural strengths (the maximum strength is 161.5 MPa), and the flexural stress-displacement curve shows better "pseudo-plastic", compared with the composites with resin carbon coating. The higher flexural strengths and better "pseudo-plastic" of the composites with resin carbon coatings can be achieved by appropriate high temperature treatment.