Influence of contour scans on surface roughness and pore formation using Scalmalloy® manufactured by laser powder bed fusion (PBF‐LB)
Thorsten Reiber, J. Rüdesheim, Matthias Weigold, Eberhard Abele, Jens Musekamp, Matthias Oechsner
Abstract
Abstract The scandium modified aluminium alloy Scalmalloy® is specifically developed for the use in laser‐based powder bed fusion (PBF‐LB). It is supposed to show potential in the production of lightweight structures due to its high specific strength compared to other aluminium alloys. A limiting factor is the high surface roughness of additively manufactured parts, which has a negative influence on its mechanical properties, especially under cyclic loads. In order to reduce the surface roughness, methods of design of experiments (DoE) are applied to develop contour parameters. Additionally, the formation of pores in keyhole‐mode welding and strategies to reduce the porosity in the contour area are investigated. The surface roughness of vertical walls can be reduced down to Ra < 7 μm using contour scans with a line energy E L >0.9 J mm −1 but keyhole pores start to form applying E L >0.6– 0.75 J mm −1 . Two contour parameter sets in different E L ‐ranges are developed that can be used to reduce the surface roughness compared to parameter sets without contour scans, without increasing the porosity in the contour area. Their impact on the mechanical properties has to be further investigated.