Method of fabricating ceramic matrix composites employing a vacuum mold procedure

摘要

A method of fabricating a discontinuous-fiber, ceramic matrix green-state composite component. The method includes preparation of a mixture of discontinuous fibers, in a quantity equal to about 100% of a desired end-product fiber quantity thereof, and a polymer-derived ceramic precursor resin in an excess quantity greater than about 150% of a desired end-product resin quantity thereof. The mixture so prepared then is introduced into a cavity of a molding tool and a vacuum is applied to the cavity through a vacuum aperture leading from the cavity. The mixture is drawn toward the vacuum aperture and consequently compacts a quantity of fibers within the cavity at the aperture site such that the fibers function as a filter to efficiently retain within the cavity fibers within the original mixture while removing under vacuum the excess resin that provided an effective vehicle for carrying and dispersing the discontinuous fibers. Finally, the molding tool is heated to a temperature and for a time sufficient to cure the resin/fiber mixture within the cavity and thereby fabricate the green-state composite component in a structurally sound manner.