ADVANCED POWDER METALLURGY ALUMINUM ALLOYS VIA RAPID SOLIDIFICATION TECHNOLOGY

ALUMINUM ALLOYS WITH IMPROVED HIGH TEMPERATURE CAPABILITIES ARE OF STRONG INTEREST TO NASA FOR POTENTIAL SPACECRAFT APPLICATIONS. RAPID SOLIDIFICATION TECHNOLOGY TECHNOLOGY (RST) OFFERS EXECELLENT PROSPECTS FRO CREATION OF NEW STRUCTURAL ALLOYS WITH SUPERIOR PROPERTIES NOT ACHIEVABLE BY CONVENTIONAL METALLURGY. DURING PHASE I, THIS PROJECT INVESTIGATES A NEW BASED ON MELT-SPINNING FOR MANUFACTURING RAPIDLY SOLIDIFIED POWDERS OF ALUMINUM ALLOYS CONTAINING TRANSITION METALS, FE AND CR. USING THIS PROCESS,THE STUDY EXPLORES ALUMINUM ALLOYS WITH TRANSITION METAL CONTENTS HIGHER THAN HITHERTO ATTEMPTED TO ACHIEVE IMPROVED HIGH TEMPERATURE PROPERTIES VIA THE DISPERSION HARDENING EFFECTS OF INTERMETALLIC PHASES. THREE, AL-FE-CR, ALLOYS AREPREPARED AS RAPIDLY SOLIDIFIED POWDERS CONSISTING OF A SINGLE METASTABLE SUPERSATURATED SOLID SOLUTION PHASE. UPON DECOMPOSITION OF THE AS-SOLIDIFIED PHASE AT HIGH TEMPERATUREDURING CONSOLIDATION PROCESSING, A THERMALLY STABLE ULTRAFINE DISPERSION OF INTERMETALLIC PHASE(S) BASED ON ALUMINUM AND TRANSITION METALS IS FORMED WHICH LEADS TO IMPROVED TENSILE, CREEP, AND FATIGUE PROPERTIES AT ELEVATED TEMPERATURES.