OXIDATION PROTECTION COATING FOR TITANIUM ALUMINIDES

TITANIUM ALUMINIDES REQUIRE OXIDATION AND HYDROGEN RESISTANT COATINGS TO ACHIEVE LONG-TERM STRUCTURAL INTEGRITY FOR USE IN MULTIMISSION HYPERSONIC VEHICLES. WE PROPOE TO DEMONSTRATE THE FEASIBILITY OF CONTROLLING THE DIFFUSION OF OXYGEN AND HYDROGEN BY THE USE OF A NOVEL MULTILAYER GLASS-CERAMIC COATING WHICH HAS BEEN SURFACE GLAZED USING A HIGH ENERGY LASER. NEW CLASSES OF HIGHTEMPERATURE GLASSES AND GLASS CERAMICS ARE PROPOSED WHICH CAN MATCH THE THERMAL EXPANSIONS OF TITANIUM ALUMINIDES AND CONTROL THE GASEOUS DIFFUSION. SPARTA'S NEW ALKOXIDE PROCESSING TECHNIQUES WILL BE USED TO DEPOSITE THE MULTILAYER COATINGS. PRELIMINARY SCREENING AND EVALUATION OF THE COATINGS WILL BE PERFORMED USING OPTICAL AND SCANNING ELECTRON MICROGRAPHY, GASEOUS DIFFUSION TESTS, AND 20 CYCLES OF HEATING FROM ROOM TEMPERATURE TO 1800 DEG F.