Wire Based Directed Energy Deposition of JBK-75

Abstract

Applications and adoption of metal additive manufacturing (AM) are increasing for fabrication of low volume, complex components with novel materials, as well as replacement parts. While the use of powder bed fusion-based processes have been widely used to build complex components with fine feature resolution, there is a volume limitation. Expanding the application of metal AM will rely on other processes that remove this build size constraint. These processes are referred to as Directed Energy Deposition (DED) and can use either powder or wire feedstock. Wire based DED provides the highest deposition rates which shortens the fabrication time making it attractive for fabrication of large parts replacing traditional wrought billets or castings. In this study, an iron-based austenitic superalloy (JBK-75) was deposited using an arc-based, wire-fed (AW)-DED process. The material was metallographically characterized and quasi-static mechanical properties were obtained. The resulting microstructure and mechanical properties are compared with conventional wrought and cast forms of JBK-75 subjected to the same heat treatments. As compared to wrought material, the AW-DED grain size was larger after the heat treatment, although the strengths were similar. Improved homogenization was observed after heat treatment in the AW-DED specimens as compared to the cast specimens.