Einfluss der Abkühlrate auf die mechanischen Eigenschaften von additiv gefertigten Zugproben aus 316L

Effect of cooling rate on the mechanical properties of 316L tensile specimen, manufactured by Laser Powder Bed Fusion. Laser-Powder Bed Fusion (LPBF) is an additive manufacturing process, which allows weight savings of components through structural optimization without loss of stiffness. The mechanical properties are comparable with casted and – under ideal conditions – even with forged components. In the aerospace industry, as well as in the automotive and medical sector, LPBF is already applied. However, LPBF has only been used for components which are not safety-related. This is mainly due to the unreliable reproducibility of the mechanical properties of this process. Research has to be executed to find correlations between LPBF-parameters and reliable product properties. This report investigates the relationship between cooling rates in the LPBF process and the resulting mechanical properties of 316L (1.4404). For this purpose, different sample geometries were manufactured. The respective cooling rates were measured by in-situ-thermography. After that, tensile tests and metallurgical investigations were performed. Depending on the geometry, different cooling rates were observed, which finally led to different tensile strength results.