Experimental investigations on wire arc additive manufacturing process using an Inconel 625 alloy wire

The current research investigates the use of an automated cladding welding machine for wire arc additive manufacturing (WAAM) of a semi-cylindrical part using a 1.2mm nickel- chromium-molybdenum alloy wire (ERNiCrMo-3). The gas tungsten arc welding process was adopted to create a 32mm thick and 60mm long part. Onwards, standard tests were performed to evaluate the part's hardness, yield, and tensile strengths at various sections along the part's length and thickness. One of the objectives was also to identify any potential change in the mechanical properties of the Nickel wire when employed in WAAM process. Moreover, microstructure along the depth was examined using SEM to ascertain bonding between deposited layers and identify any porosities. The material's hardness was found relatively higher than the original wire; somewhere about 27 HRC in the horizontal plane and 26.8 to 28.5 HRC in the vertical plane. Additionally, the study shows that the direction across the thickness (X) had the lowest values for both tensile and yield strength. While, examination at the microscopic level revealed that in both orientations: parallel (X) and perpendicular (Y) to the direction in which the layers were deposited, exhibited a high level of ductility. This confirms the possibility of an additive manufacturing procedure adopted for this super-alloy material without significantly changing its mechanical properties. While, there is room for improvement in properties by optimizing the machine parameters.