NIOBIUM ALUMINIDE (NBAL[3]) BASED HIGH TEMPERATURE MATERIALS FOR ADVANCED SYSTEMS

NIOBIUM ALUMINIDE (NBAL[3]) BASED MONOLITHIC AND COMPOSITE MATERIALS HAVE POTENTIAL AIR FORCE APPLICATIONS IN THE TEMPERATURE RANGE 2000-3000 DEG F IN ADVANCED GAS TURBINE ENGINES AND ADVANCED TRANSATMOSPHERIC FLIGHT VEHICLES. NBAL(3) BASED MATERIALS HAVE PROVED TO BE RATHER FORMIDABLE MATERIALS TO PROCESS BECAUSE OF ITS EXTREME BRITTLENESS. FOR SUCCESSFUL PERFORMANCE DURING LONG TERM ELEVATED TEMPERATURE SERVICE THESE MATERIALS MUST ALSO EXHIBIT HIGH CREEP RESISTANCE. THE PROPOSED RESEARCH WILL DETERMINE THE FEASIBILITY OF OPTIMIZING THE ROOM AND ELEVATED TEMPERATURE MECHANICAL PROPERTIES BY USE OF RAPID SOLIDIFICATION AND POWDER METALLURGICAL PROCESSING. THE LONG TERM OBJECTIVE IS TO DESIGN AN ENGINEERED MULTIPHASE NBAL(3) MATRIX COMPOSITE. PHASE I RESEARCH WILL INVESTIGATE THE EFFECT OF TIB(2) DISPERSOIDS ON THE MICROSTRUCTURAL AND MECHANICAL PROPERTIES OF RAPID SOLIDIFIED NBAL(3). DURING PHASE I RESEARCH SUITABLE THERMOCHEMICALLY STABLE DUCTILE PHASE AND CONTINUOUS FIBER REINFORCEMENTS TO THE NBAL(3) MATRIX WILL ALSO BE IDENTIFIED USING THERMODYNAMIC CALCULATIONS.