DUCTILE TI(3)AL ALLOYS FOR TACTICAL MISSILES

THE PHASE I OBJECTIVE IS TO SHOW THE FABRICATION FEASIBILITY OF A DUCTILE TITANIUM ALUMINIDE ALLOY THAT IS SUITABLE FOR USE AS A STRUCTURAL MATERIAL IN FUTURE NAVSEA TACTICAL MISSILE SYSTEMS. A SPECIFIC GOAL IS TO PROVIDE A MATERIAL THAT HAS A DENSITY OF APPROXIMATELY 50% OF THAT OF SUPERALLOYS AND A SIMILAR OPERATING TEMPERATURE. THE APPROACH IS TO UTILIZE ZIRCONIUM AS A SUBSTITUTIONALELEMENT FOR TITANIUM IN THE TI(3)AL HIGLY ORDERED HEXAGONAL CRYSTAL LATTICE STRUCTURE. THIS WILL HAVE THE EFFECT OF CREATING A MINOR EXPANSION AND "DISORDERING" OF THE LATTICE AND THUS, WILL CREATE MORE POSSIBILITIES FOR ADDITIONAL SLIP PLANS WITHIN THE CRYSTAL. FOR MAXIMUM DUCTILITY, PURITY OF ALL STARTING MATERIALS IS CONSIDERED ESSENTIAL AND VACUUM CASTING WILL AVOID CONTAMINATION FROM OXYGEN, HYGEN AND NITROGEN. CONTROLLED VARIATIONS IN THE ALUMINUM, TITANIUM, AND ZIRCONIUM CONTENT WILL BE USED IN ORDER TO DETERMINE THE OPTIMUM DUCTILITY AND ELEVATED TEMPERATURE SPECIFIC MECHANICAL PROPERTIES OF THE ALLOY. COMPOSITIONS AS HIGH IN ZR AS 45ZR, 45TI, 10AL WILL BE FABRICATED AND TESTED. IN PHASE II, ACTIVITIES WILL INCLUDE (1) USE OF MORE DUCTILE TIZRAL ALLOY AS A COMPOSITE MATRIX, AND (2) A DEMONSTRATION OF ALLOY FABRICABILITY OF ACTUAL TACTICAL MISSILE STRUCTURAL COMPONENTS.