A High Production Rate Process to Fabricate Low Cost High Strength MMCs In Net Shape

Military systems are traditionally produced in steel because of excellent mechanical properties and low cost. For a lighter weight and more mobile force, all aspects of military systems are being scrutinized for possible weight reduction. Metal matrix composites with discontinuous reinforcements offer the potential for the very high strength and modulus required for targeted Army applications such as armor, gun barrels and a plethora of structural applications. In Phase I, MER demonstrated the capability to produce a Ti-6Al-4V MMC reinforced with TiB or AlN with excellent properties. The tensile strength achieved 87% of the Phase II goal, and the modulus exceeded the goal. The microstructure showed an excellent uniformity of the elongated TiB crystals which have a diameter of ~1ƒÝ and a length of >50ƒÝ. The Ti-6Al-4V matrix strength was also enhanced by the addition of submicron AlN. The composites were produced using MER¡¦s low cost plasma transferred arc rapid additive manufacturing process capable of producing near net shape components in which plates and tubes were demonstrated. In Phase II, the optimum loading and morphology of the ceramic particulate phase will be optimized to exceed the Phase II property goals. Fabrication of plates, tubes, and other geometries will be demonstrated by the low cost manufacturing process providing a demonstrated capability to immediately translate into field applications.