| 摘要 |
PROBLEM TO BE SOLVED: To obtain a ceramic having good toughness and good strength for a long time at high temperature by covering fibers with coating films in which inclusions are dispersed. SOLUTION: Fibers 2 are arranged in a ceramic matrix 1. The fibers 2 are covered with coating films 3. In the coating films 3, fine inclusions, namely particulate inclusions 4, whisker-like inclusions 5 and flaky inclusions 6 are dispersed. The matrix 1, the fibers 2, the coating films 3, and the inclusions 4-6 are produced from a ceramic such as a carbide (e.g. SiC), a nitride (e.g. SiN) or an oxide (e.g. ZrO). This method for forming the coating films 3 comprises adding the inclusions 4-6 to a polymer capable of being decomposed into the ceramic, such as a liquid polycarborane polymer, coating the surfaces of the fibers with the dispersion in a prescribed thickness and subsequently sintering the coated dispersion at 800-1800 deg.C. The sintering temperature is higher than the use temperature of the ceramic. The inclusions desirably have sizes of 0.1 μm to several ten μm. The sizes prevents the development of cracks 7. The thickness of the coating films is 0.5 μm to several tens tens μm. |
