Effect of directed energy deposition processing parameters on laser deposited Inconel® 718: External morphology

Through laser-based, directed energy deposition, single-track bead-on-plate clads of Inconel (R) 718 were deposited onto substrates of the same composition. Postprocessing analyses of the geometry of the single beads were made to assess the effects of changes in processing parameters. Laser power, travel speed, working distance, and initial substrate temperature were varied to alter the shape of the laser deposited material. The resulting geometries were analyzed through metallography and optical profilometry. This study concludes that laser power has the largest effect on bead width, and that working distance has the largest effect on bead height and angle of repose. Additionally, substrate preheating was found to amplify the effects of varying power on bead height and width. Empirical models were developed to describe the geometry of single beads based on chosen processing parameters. These models were compared to optical profilometry measurements for accuracy. (C) 2017 Laser Institute of America.