Effect of process parameters on wire-arc direct energy deposited Inconel 718 superalloy

Purpose Owing to its leverage of high deposition rate, the wire arc additive manufacturing (WAAM) process is being adopted for the development of IN718 alloy used in aerospace, transportation and energy sectors. The purpose of this study is to observe the effect of process parameters on the mechanical properties of the IN718 superalloy. Design/methodology/approach This study emphasizes the effect of WAAM process parameters on mechanical and metallurgical properties of developed multilayer structures of IN718 alloy by means of orthogonally designed experiments. Findings The results show that high current and voltage settings, combined with low welding speed, provide increase bead width, height and effective wall area, while resulting in decrease surface waviness, hardness and tensile properties. The scanning electron microscopy and energy dispersive spectroscopy results show the presence of secondary precipitates such as NbC and Ni3(Al, Ti) in low-heat samples, which improve the mechanical properties of the material. However, the presence of Laves phases deteriorates the mechanical properties in high-heat samples. The electron backscatter diffraction results confirmed the presence of more grain boundaries and highly textured surfaces in lower heat samples, which improves mechanical properties. Originality/value The effect of process parameters on the microstructural features and mechanical properties along with bead characteristic are studied in-depth and influence of each parameter are discussed.