Effect Of Build Parameters on Mechanical Properties and Residual Stresses of LP-DED Inconel 718 Overhanging Structures

Additive manufacturing of Inconel 718 via laser powder direct energy deposition (LP-DED) offers design flexibility for repair and fabrication of large components. However, mechanical properties remain sensitive to process parameters and geometric constraints, which impact the consistency of material properties. This study investigates the effect of different build angles (0°, 20°, 30°, and 35°) at different laser powers (1070W and 2000W) on the mechanical properties and residual stresses. Eight overhanging structures were fabricated using Inconel 718 and subjected to various heat treatments (SR + HIP + SOL + Aging). Numerical simulations were developed to predict residual stresses in the samples, and the models were validated through X-ray diffraction measurements of residual stresses. Specimens were machined from the samples for tensile and high-cycle fatigue (HCF) testing. The paper concludes with a comparison and remarks on the repeatability and reproducibility of material properties between different build angles and power approaches.