Effect of NiO nanoparticles on duplex stainless steel processed via DED-LB and PBF-LB

Abstract

Duplex stainless steels (DSS) are defined by their equal phase composition of ferrite and austenite. However, the in-situ formation of this duplex microstructure in laser-based additive manufacturing (AM) is still a challenging topic. Nanoparticle addition is a promising approach to tailor the microstructure of steels in AM. Therefore, DSS doped with 0.5 wt.-% NiO nanoparticles was fabricated by laser-based powder bed fusion (PBF-LB) and directed energy deposition (DED-LB). While having no impact on the phase composition in PBF-LB, the addition of NiO nanoparticles showed a significant increase in austenite content of 9% compared to the unmodified powder in DED-LB.