A SUPERPLASTIC OXIDE DISPERSION STRENGTHENED MAGNESIUM ALLOY FOR AUTOMOTIVE APPLICATIONS

REDUCTION OF AUTOMOBILE WEIGHT IS AN IMPORTANT APPROACH TO REDUCING FUEL CONSUMPTION. MAGNESIUM ALLOYS WOULD OFFER THE POTENTIAL FOR SIGNIFICANT WEIGHT REDUCTIONS IF THEY WERE MORE READILY FORMED AND THEIR STIFFNESS COULD BE INCREASED. HIGH STRAIN RATE SUPERPLASTIC FORMING OFFERS A COST EFFECTIVE ROUTE FOR THE PRODUCTION OF AUTOMOTIVE COMPONENTS. HOWEVER, TO BE SUPERPLASTIC, MAGNESIUM ALLOYS MUST POSSESS A UNIQUE SET OF MICROSTRUCTURAL FEATURES. MAGNESIUM ALLOY SYSTEMS WHICH POSSESS SUCH MICROSTRUCTURES ARE NOT READILY AVAILABLE. RECENTLY A NEW CLASS OF LOW COST, CORROSION RESISTANT, OXIDE DISPERSION STRENGTHENED (ODS) MAGNESIUM ALLOYS HAVE BEEN SYNTHESIZED BY A NOVEL LIQUID METAL PROCESS. THESE MATERIALS MEET THE MICROSTRUCTURAL REQUIREMENTS FOR SUPERPLASTICITY AND BASED ON PREVIOUS RESEARCH, SHOULD BE SUPERPLASTIC AT STRAIN RATES CONSISTENT WITH CONVENTIONAL FORMING PROCESSES (10(0) TO 10 1/S). THESE ODS ALLOYS ALSO OFFER A 45 TO 190% INCREASE IN STIFFNESS COMPARED TO CONVENTIONAL MAGNESIUM ALLOYS. DURING PHASE I, ODS MAGNESIUM ALLOYS WILL BE PRODUCED, EXTRUDED, AND TENSILE TESTED AT ELEVATED TEMPERATURES AND A VARIETY OF STRAIN RATES TO DETERMINE IF THEY ARE INDEED SUPERPLASTIC.