Welding Journal Research Supplement

Abstract

Further development of manufacturing methods and metallic alloys is crucial for creating next generation energy production systems with enhanced strength, toughness, creep resistance, and/or corrosion resistance. For wire-based additive manufacturing (AM), wire materials are often cheaper than powdered metal, impurity contents are easier to control, deposition rates are substantially higher than those of powder based AM, and wire arc AM is backed by decades of experience in multipass welding, cladding, and build-up repairs. To further expand the capabilities of wire arc additive manufacturing, a multiwire gas tungsten arc welding AM system was developed to independently introduce two commercially available nickel-based alloys, Alloy 617 and Alloy 740H, as weld wires into a single weld pool, thereby introducing chemical composition gradients with the intent of altering local material properties. This research analyzed weld metal dilutions and evaluated the composition profiles at different proportions of nickel alloy filler wires. The work demonstrated that multiwire gas tungsten arc-directed energy deposition can deposit graded compositions predictably via a simple mathematical analysis based on mass balance.