Optimized Metal Matrix Composite Feedstock for Additive Manufacturing

With increasing demands for higher performance and lower weight for equipment and vehicles, the United States Army is seeking ways to incorporate composites into various structures ranging from gun barrels to air frames. Composites, unlike traditional metals or ceramics, provide high strengths with minimal weight penalties. For this effort, the Army is primarily looking for development of a metal matrix composite (MMC) that can be used as a feedstock material for additive manufacturing processes for the fabrication of various primary structures ranging from vehicular components to gun components. In order to address the need for a MMC feedstock for additive manufacturing, Touchstone proposes to optimize the current fiber reinforced aluminum it produces specifically for the ultrasonic additive manufacturing (UAM) process, which will allow for the fabrication of high strength, lightweight structures. The UAM process involves building up solid metal objects through ultrasonically welding a succession of metal tapes into a three-dimensional shape, with periodic machining operations to create the detailed features of the resultant object. The process is also able to weld preplaced foils/layers instead of tapes and has been able to weld the MMC material that Touchstone produces. During the Phase I effort, Touchstone aims to increase the fiber volume of the MMC feedstock to allow for higher strengths and apply a thin aluminum coating onto the surface of the feedstock through spray coating processes in order to avoid fiber breakage during UAM processing while reducing processing time. Touchstone will partner with Fabrisonic LLC in order to fully develop the MMC feedstock and UAM process to allow for the fabrication of various structures and test articles that will benefit the Army by increasing capabilities of components while lowering the overall weight of the structure.