Functional Graded Conductor Rails for Electromagnetic Launchers Navy SBIR FY2010.1 Sol No.: Navy SBIR FY2010.1 Topic No.: N101-086 Topic Title: Functional Graded Conductor Rails for Electromagnetic Launchers Proposal No.: N101-086-1487 Firm: Plasma Processes, Inc. 4914 Moores Mill Road Huntsville, Alabama 35811-1558 Contact: Daniel Butts Phone: (256) 851-7653 Web Site: www.plasmapros.com Abstract: The US Navy is pursuing the development of an electromagnetic rail gun (EMRG) for long range naval surface fire support. Such guns have been built and operated successfully on a test basis, however several obstacles prevent them from usage in the field. One specific obstacle is the development of suitable materials for the conductor rails. Copper and Cu alloys have been materials of choice for electrical and thermal conductivity considerations. However, abrasion, rail arcs, balloting loads and molten armature metals easily degrade bare Cu surfaces. As a result multiple firings are not possible without significant barrel repair. In order to maximize electrical/thermal conductivity, Cu alloys are likely inescapable. In order to minimize damage to Cu rail, a material with a high melting temperature and high density is essential. Therefore, a rail structure that most practically meets these requirements would have a Cu-based core and a refractory metal surface. However, issues associated with coefficient of thermal expansion mismatch have challenged the production of such a structure via conventional manufacturing techniques. During a Phase I investigation, the ability to form a functionally graded Cu/refractory metal conductor rail surface will be evaluated. The ability to form net-shape, non-planar geometries and the feasibility to grade the through thickness properties will also be investigated. Benefits: The proposed innovation will enable the employment of advanced conductor rails for electromagnetic launchers, capable of withstanding the harsh environment of the gun bore for multiple firings. As a result, the costly and labor-intensive bore repair/maintenance schedule would be significantly reduced. The proposed technology is also applicable to rocket nozzles, combustion chambers, armor and nuclear applications where joining of materials with dissimilar coefficients of thermal expansion is required. Return