Titanium Metal Matrix Composite Systems with Enhanced Elevated Temperature Properties for Advanced Turboshaft Engine Impeller Applications

This proposal addresses the need for high temperature titanium metal matrix composites (MMC) for advanced turboshaft engine impellers. Dynamet Technology’s particulate reinforced titanium MMCs have superior room and elevated temperature strength, are stiffer and have better creep resistance than conventional titanium alloys. New Ti MMC compositions based on a novel alloy matrix exhibit significantly improved room and elevated temperature properties and specific strengths (strength/weight). The objective of Phase 1 is to demonstrate that these new Ti MMC compositions can meet the demands placed on impellers from higher temperatures and pressures required for advanced turboshaft engines. In Phase 1 selected compositions will be produced and evaluated. The manufacturability of these materials will be demonstrated. The evaluation will include density determination, room and elevated temperature tensile testing, chemical and metallographic analyses. Program support will be provided by Honeywell Aerospace/Advanced Technology. During the Phase 1 Option, creep resistance testing of promising composition(s) will be conducted at the maximum design compressor exit temperature of these advanced engines. In Phase II materials and processes will be developed for the manufacture of impellers and tested for required properties such as; tensile properties, fatigue and creep resistance, fracture toughness and crack growth at room and elevated temperatures.