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The additive manufacturing (AM) of components through laser-blown-powder directed-energy-deposition (LBP-DED) is highly applicable to the repair of aerospace components. Fabrication of superalloys with this technique, as with other AM methods, often encounters complications that include the formation of undesired phases, irregular microstructure and texture leading to anisotropic elastic properties. Heat treatments and other post-processing techniques can be used to mitigate these issues. The collected data demonstrates the effects of different heat treatment protocols on the microstructure, elastic properties, and hardness of LBP-DED IN718. In this study eight different heat treatment were used to investigate the effects of treatment time and temperature. The microstructure was investigated through SEM, with XRD and EDX used for phase analysis. The texture was characterised using SEM coupled with EBSD and the elastic properties were determined from resonant ultrasound spectroscopy.

Challenges are encountered with the laser-blown-powder directed-energy-deposition (LBP-DED) of high-performance alloys such as IN718. Complications that arise include the formation of undesired phases, irregular microstructure, and pronounced texture leading to anisotropic elastic properties. To mitigate these issues, deposition parameters and post-processing treatments must be carefully selected to achieve the desired properties in the final product. In this study it is shown that a Brass texture component ({110} ) can be achieved in LBP-DED IN718. EBSD analyses indicate that this texture is enhanced through partial recrystallisation following selected heat treatments, increasing the degree of microstructural anisotropy. Interestingly, resonant ultrasound spectroscopy (RUS) results indicate a decrease in the elastic anisotropy with recrystallisation. This is hypothesised to be a result of the pronounced Brass texture leading to pseudo-isotropic elastic properties along the cubic axes. Further insight into the kinetics of this process have been obtained with in-situ high temperature RUS measurements.