Effect of continuous and pulsed current techniques on wire-arc additive manufacturing of a nickel-based superalloy.

[Display omitted] • Hastelloy C-276 thick wall was successfully fabricated. • Pulsed current shows fine equiaxed and cellular structure. • Pulsed current mode minimized the segregation phenomenon. • Overall pulsed current provides better properties than continuous current. In this research, the Hastelloy C-276 thick wall component was successfully fabricated using wire arc additive manufacturing (WAAM) with both continuous current (CC) and pulsed current (PC) techniques. A defect-free components produced from appropriate process parameters. The CC-WAAM exhibits equiaxed structure in top and columnar in middle and bottom layers. PC-WAAM has fine-equiaxed and cellular structure. The controlled heat input from arc pulsing mode minimized elemental segregation between inter-dendritic and dendritic core regions. CC-WAAM wall have a maximum average grain size of 223.7 μm, while PC-WAAM wall have 189.2 μm. PC-WAAM has higher strength, hardness, and ductility than CC-WAAM. This paper presented a better gas tungsten arc welding (GTAW) based WAAM technique for industrial component manufacturing based on Hastelloy C-276 microstructure and mechanical integrity tests. [ABSTRACT FROM AUTHOR]