Study on the Arc Additive Manufacturing Process and Mechanical Properties of Inconel 625 Nickel-Based Alloy Bulk

Abstract

The melt-inert gas-shielded arc additive manufacturing experiment of Inconel 625 nickel-based alloy bulk was carried out. The influence of current mode, current, travel speed, weld bead spacing, deposition path, and arc length on the formation of overlapping weld beads was studied. The incomplete fusion near the bottom weld toe of adjacent weld beads was the main defect. The optimized parameters for bulk additive manufacturing obtained from the experiment were as follows: pulse current of 70 A, travel speed of 200 mm/min, weld bead spacing of 3 mm, dry extension of 10 mm, continuous deposition, and arc length of 1 mm. Due to the thermal influence during the deposition of adjacent weld beads, directional grains were formed inside the weld bead and at the boundary with adjacent weld beads. However, the direction of grain growth was not uniform throughout the entire weld bead, and a consistent texture of the entire weld bead was not formed. The tensile strengths of the specimens in the X, Y, and Z directions were 858.5, 838.7, and 827.2 MPa, respectively, and the fracture elongations were 53.3%, 37.6%, and 42.1%, respectively. The strength in the Z direction, which is the vertical direction, was the lowest. arc additive manufacturing; nickel-based alloy; incomplete fusion; texture