Fabrication of fiber reinforced ceramic composites by chemical vapor infiltration

TLDR: In this paper, the authors presented a process, fabricated hardware, and demonstrated on a laboratory scale a process which permits CVD infiltration of an SiC fibrous preform with either an Si/sub 3/N/sub 4 or SiC matrix in 2 to 12 hours.

Abstract: Ceramic fiber-ceramic matrix composites were prepared using the chemical vapor deposition (CVD) process. Our major goal of significantly reducing the infiltration times was accomplished. We have conceived a process, fabricated hardware, and demonstrated on a laboratory scale a process which permits CVD infiltration of an SiC fibrous preform with either an Si/sub 3/N/sub 4/ or SiC matrix in 2 to 12 h. The process should be applicable to infiltration of fibrous preforms prepared by slurry molding, stacking of layers of cloth, or filament winding. Two types of composites (SiC-Si/sub 3/N/sub 4/ and SiC-SiC) have been produced at densities of about 2.0 Mg/m/sup 3/ which was near the desired range. A scheme has also been conceived whereby the new infiltration process could be used for fabrication of tubes or hollow cylinders. This is an important advance since the ability to fabricate tubes or hollow cylinders would offer the hope that the process could be used for fabrication of toughened, high-strength heat exchanger tubes, heat engine cylinder liners and valve guides. 19 references, 7 figures, 1 table.