Effect of ring-shaped beam profiles in LPBF of Nickel alloy 718 on the surface roughness

Laser Powder Bed Fusion (LPBF) is an Additive Manufacturing (AM) process which uses a laser, traditionally having a Gaussian distribution, to selectively melts the metallic powders thus allowing the printing of customized parts having complex geometries. Despite the numerous advantages offered by the LPBF, efficiency and productivity of the process represent crucial challenges which limit its large-scale production. In this regard, the use of innovative beam shapes, such as the ring one, is starting to be deeply investigated to potentially revolutionize metal AM by improving quality, efficiency and sustainability of the processes. Nevertheless, very few studies exist in the literature investigating the effect of the use of laser having ring-beam shaped profile on both quality and efficiency of the LPBF process. This work aims to fill this gap of knowledge, thus exploring and discussing the effect of the ring contribution in the LPBF process on both surface roughness and productivity of Nickel alloy 718 parts.