Direct Laser Welding of Continuous Fiber Reinforced Aluminum

The potential benefits of continuously reinforced metal-matrix composites (MMC's) for spacecraft structural applications are well established because of their excellent thermal stability, high specific stiffness and strength, high thermal conductivity, and low outgassing. Unfortunately, the use of conventional joining techniques such as adhesive bonding, mechanical fasteners, soldering, and low temperature brazing either result in outgassing contaninants, damage to the reinforcing fibers, or less than optimal joint strength. Triton Systems proposes an innovative, economical, flexible single-step rapid joining process called Directed Laser Welding (DLW) that can produce reliable high strength joints and enable quick assembly MMC ground and space-based BMDO structures. The Phase I effort is directed towards defining the optimum processing parameters necessary for direct laser joining graphite fiber reinforced aluminum test panels with greater than 50 percent joint efficiency. The joint integrity will be verified through microstructure analysis. Phase II will further develop and demonstrate DLW for different joint types and assembly of MMC structures, generate materials engineering and design data for typical joint assemblies, and develop analytical methods for modeling joint behavior.