Abstract
Laser powder bed fusion (LPBF) of Monel 400 is gaining interest; however, research remains scarce. This work provides an overview of the entire process of investigating LPBF of Monel 400. A design of experiments approach was employed to define the process parameter window wherein the as-printed product maintained a density ≥99.5%. The microstructure of the as-built Monel 400 was found to be devoid of critical defects (extensive porosity, cracks) and single phase but was segregated at the nanometric level into Ni-rich dendrites and Cu-rich inter-dendritic regions. It was determined that the extent of nano-segregation could be modified through post-build solution heat treatments that this influenced critical traits such as tensile properties and impact toughness. The tensile strength of as-built specimen was comparable to wrought cold worked and stress-relieved Monel 400, while the solutioned products were comparable to the alloy in a hot worked state. Notably, all conditions, including as-built, exhibited excellent tensile ductility to fracture and heat treated LPBF specimen were found to be equivalent to the wrought counterpart in terms of impact toughness.