(中南大学 粉末冶金国家重点实验室, 长沙 410083)
摘 要: 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。
关键字: 高温热处理; 熔硅浸渗; C/C-SiC复合材料; 弯曲强度; 断裂方式
(State Key Laboratory for Powder Metallurgy, Central South University, Changsha 410083, China)
Abstract: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 161.5MPa), 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.
Key words: high temperature treatment; molten silicon infiltration; C/C-SiC composites; flexural strengths; fracture modes