Improvements in the fabrication of ceramic-fiber-ceramic-matrix composites by chemical vapor infiltration

Development of a new, faster process for the fabrication of ceramic-fiber-reinforced-ceramic-matrix composites by chemical vapor infiltration has continued. Composites of SiC fibers infiltrated with a matrix of either SiC or Si/sub 3/N/sub 4/ have been produced. Process and equipment improvements led to the fabrication of preforms with a higher fiber content, and infiltration improvements reduced infiltration times and increased infiltrated densities. These improvements have produced composites with higher flexural strengths (up to 475 MPa) and high strain values (up to 1%). The high strength and high strain values along with the gradual loss of strength (in contrast to the sudden loss typical of ceramics) were major goals of this work.