S042014 繰返しMI法によるC/SiC複合材料の高速緻密化プロセス([S042]セラミックスおよびセラミックス系複合材料)

Abstract

A rapid and low-cost manufacturing process of a carbon-fiber-reinforced SiC matrix (C/SiC) composite was examined in this study. In this process, the space between fibers in a 3D carbon fiber preform was infiltrated by chemical vapor infiltration(CVI) and silicon melt infiltration (Si-MI). In the CVI process, pyrolytic carbon interfacial layer and SiC barrier layer were deposited on the carbon fiber surface. Then, remaining unfilled space in the pre-coated preform was filled with carbon matrix by infiltration of carbon black slurry and/or polymer impregnation and pyrolysis (PIP) of phenolic resin. The carbon filled preform was infiltrated with silicon melt at 1450℃.Then,they were further densified by several cycles of Si elimination at 1650℃ and the PIP of phenolic resin followed by the Si-MI. Through these processes, residual Si was reduced and the pores in the composite were filled by SiC. Then, the microstructure and flexural strength of the C/SiC composite at room temperature and 1200, 1400, 1600℃ were evaluated. Experimental results revealed that those composites possessed dense SiC matrix and exhibited the high flexural strength of approximately 500MPa at 1600℃.