Materials analysis of deposits made by the directed-light fabrication process

This is the final report of a one-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The directed-light fabrication (DLF) process is a unique method of forming three-dimensional objects by fusing airborne powders in the focus of a laser beam. This process bypasses conventional ingot processing steps of casting, homogenization, extrusion, forging, and possibly some or all of the required machining. It provides a new ``near-net-shape`` fabrication technology for difficult-to-fabricate materials such as refractory metals, metal composites, intermetallics, ceramics, and possibly superconductors. This project addresses the solidification behavior during DLF processing to characterize the technique in terms of solid/liquid interface characteristics, cooling rates, and growth rates. Materials studied were Ag-Cu, Fe-Ni, 316SS, and Al-Cu