RTM of high temperature polymers for engine valves

Abstract

Composite materials offer many potential benefits in engine technology, but are often limited by the temperature of the environment and by processing complexity. In this study resin transfer molding is applied to the processing of high temperature polymer matrix composites. Processing parameters are investigated and the resulting performance of internal combustion engine intake valves, produced by this method, is described. In previous efforts to produce composite engine valves, the majority of the work has resulted in multi-part valves, usually using a ceramic face, which are bonded together in a secondary operation. The present work is based on a fiber preform that includes continuous reinforcement from the valve stem through the valve face. This preform is placed in the mold and a resin transfer molding-style operation is used to produce the composite, one-piece, valve. Laboratory thermal analysis techniques are used to aid in the development of processing parameters. Additive manufacturing concepts are applied which allow the realization of location-specific material properties. The result is a one-piece valve with near net shape properties that has been demonstrated in a running engine.