Laser Powder Bed Fusion of Stainless Steel 316L Using a Flexible Dual Fiber Laser Array

In recent years, Laser Powder Bed Fusion (LPBF) has become an industrially established manufacturing technique. State-of-the-art LPBF machines feature a combination of fiber lasers and galvanometer scanners due to their high dynamic and excellent focusability. To increase the productivity of LPBF machines the number of laser scanner systems (LSS) is multiplied, which causes an almost linear increase of machine costs. In this study a flexible optical system which allows the combination of two fiber lasers with a single galvanometer scanner is developed and integrated into a LPBF lab machine to scale the productivity within one scan field. The resulting machine is characterized and used for the manufacturing of test specimen out of stainless steel AISI 316L. The manufactured specimens are analyzed in terms of melt pool formation via high-speed videography as well as resulting part density and build-up rate. The obtained results are compared with state-of-the-art LPBF-machines.