US 4,580,524 AGranted

Process for the preparation of fiber-reinforced ceramic composites by chemical vapor deposition

AssigneeThe United States of America as represented by the United States Department of Energy

InventorsWalter J. Lackey, Jr., Anthony J. Caputo

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Abstract

A chemical vapor deposition (CVD) process for preparing fiber-reinforced ceramic composites. A specially designed apparatus provides a steep thermal gradient across the thickness of a fibrous preform. A flow of gaseous ceramic matrix material is directed into the fibrous preform at the cold surface. The deposition of the matrix occurs progressively from the hot surface of the fibrous preform toward the cold surface. Such deposition prevents the surface of the fibrous preform from becoming plugged. As a result thereof, the flow of reactant matrix gases into the uninfiltrated (undeposited) portion of the fibrous preform occurs throughout the deposition process. The progressive and continuous deposition of ceramic matrix within the fibrous preform provides for a significant reduction in process time over known chemical vapor deposition processes.

Claims8

Dependent claims

Apparatus for performing vapor deposition on a fibrous or porous substrate, comprising:

(a) a housing having a chamber with an opening at one end thereof;
(b) means for mounting a porous or fibrous substrate having opposite surfaces and outer edges in said opening in the housing chamber with said outer edges spaced from said housing for defining therewith a gas receiving void in registry with said housing chamber;
(c) heating means in association with the housing chamber for heating the surface of the fibrous substrate facing into the housing chamber;
(d) cooling means for cooling the surface of the fibrous substrate facing away from the housing chamber;
(e) means for providing a flow of reactant gas to the cooled surface of the fibrous substrate;
(f) seal means disposed between said housing and the cooled surface of the substrate for conducting the reactant gas into said substrate;
and
(g) means exhausting from the housing chamber the gases exiting the heated surface of the fibrous substrate during initial phases of the vapor deposition and then from the edges of the substrate through said gas receiving void from the housing chamber,
the heating means and the cooling means, when in use, creating a temperature gradient across the fibrous substrate.

6 more elements

Dependencies are inferred from the claim text.