Microstructure and hardness of fiber laser deposited Inconel 718 using filler wire

A continuous wave 5 kW fiber laser welding system was used to deposit INCONEL® alloy 718 (IN718) layers in conduction mode by applying filler wire with a composition similar to the parent metal, which was extracted directly from a scrapped, service-exposed IN718 aerospace component. The quality of the deposits was characterized in both the as-deposited and fully heat-treated conditions in terms of the macrostructure, defects, microstructure, and hardness. Integral deposits with no visible porosity were obtained using the fiber laser deposition technique. In the as-deposited clad zone, weld metal liquation cracking led to the presence of minor microcracks in the lower layer beads near the layer interface. The crack healing behavior observed after post-clad heat treatment of the IN718 deposits supports the marked potential of using the laser deposition technique by filler wire addition to manufacture and repair/remanufacture superalloy components for aerospace applications.