Microstructure and microhardness studies of Inconel 718, manufactured by selective laser melting and subjected to severe plastic deformation and annealing

Abstract

Abstract Microstructure investigations and microhardness measurements have been comparatively performed for the nickel-based superalloy Inconel 718 produced by selective laser melting (SLM) and conventional technology. The superalloy produced by SLM had a finer γ grain size and a developed dislocation substructure in contrast to a conventional wrought material. High pressure torsion of the superalloy led to a refinement in the microstructure and an increase in the microhardness in both superalloys. Annealing at 600 °C for 2 hours of the deformed superalloys caused an additional increase in microhardness. The microhardness of the SLM material was slightly higher than that of the conventional superalloy.