Characterization of RS relaxation and precipitation behaviours as a function of energy input in a L-PBF IN718 material

The Laser based Powder Bed Fusion (L-PBF) technique alows the manufacturing of complex shaped components. Nevertheless, a disadvantage of this technology is the high magnitudes of residual stress (RS) present in as-built components. The optimal heat treatment to remove the potentially deleterious RS needs to be balanced against obtaining suitable microstructures and properties. Most RS studies on IN718 relaxation focus on a single processing strategy, investigating ex-situ specimens at discrete temperatures and times. Nevertheless, the influence of the componnet thermal history on recrystallization and precipitation of the strengthening phases has been not yet investigated in detail. Therefore, an in-situ study fis proposed to provide further fundamental understanding of the stress relaxation behaviour of L-PBF IN718 microstructures as a function of manufacturing process parameters.