OXIDATION RESISTANT TI/6A1/4V-SIC COMPOSITE MATERIALS BY IONIMPLANTATION

THE PROPOSED RESEARCH WILL SHOW THE FEASIBILITY OF EXTENDINGTHE OPERATING TEMPERATURE OF SIC REINFORCED TI/6A1/4V COMPOSITES BY ION IMPLANTATION. HIGH TEMPERATURE LIFETIME OF THESE COMPOSITES IS PRESENTLY LIMITED BY OXIDATION AND EMBRITTLEMENT TO A FEW HOURS OR LESS; DISCOVERY OF AN EFFECTIVE OXIDATION INHIBITOR COULD INCREASE THIS TO MORE THAN 800 HOURS AT TEMPERATURE, A RANGE CONSISTENT WITH MISSION REQUIREMENTS FOR HYPERSONIC VEHICLES SUCH AS NASP, THE NATIONAL AEROSPACE PLANE. ION IMPLANTATION OF TI HAS PREVIOUSLY BEEN FOUND TO SIGNIFICANTLY ENHANCE ITS OXIDATIONRESISTANCE BY BLOCKING THE EASY DIFFUSION PATHWAYS FOR OXYGEN INGRESS. THE PROPOSED WORK WILL TEST IMPLANT SPECIESFOR PROVIDING OXIDATION RESISTANCE ON LABORATORY COUPONS ANDWILL DEMONSTRATE THE OXIDATION BEHAVIOR OF COMPOSITE PANELS FABRICATED FROM IMPLANTED FOILS.