Ceramic composite valve for internal combustion engines and the like

Method of making a ceramic valve or a preform valve comprising the steps of:

• (i) providing a flexible elongated sleeving of ceramic fibers which is sized for insertion in the valve guide of an engine and is packed with an axially aligned unidirectional cluster of ceramic reinforcing fibers;
• (ii) merging one end of said sleeving into and within flexible ceramic valve bell portion containing discontinuous randomly oriented ceramic fibers to provide a valve-shaped structure;
• and
• (iii) impregnating and rigidizing said shaped structure with a matrix of carbon, of other ceramic material, or of both carbon and other ceramic material.

A ceramic composite valve for an internal combustion engine or the like including:

• (a) an elongated valve stem shaped for insertion in the valve guide of an engine and comprising a ceramic sleeving which is packed with an axially aligned unidirectional cluster of ceramic reinforcing fibers;
• and
• (b) a ceramic bell shaped for mating with the valve seat of an engine and containing discontinuous ceramic fibers;
• one end of said valve stem sleeving being molded into the bell to form a valve-shaped structure;
• and said valve shaped structure being impregnated and rigidized with a matrix of carbon, other ceramic material or both carbon and other ceramic material, and coated with a hard ceramic coating which is resistant to oxidation and wear.