The Effects of Heat Balance on the Void Formation within Marage 300 Processed by Selective Laser Melting

This contribution shows the results of a study that was conducted on the effects of varying selective laser melting (SLM) process parameters on the formation of microstructural voids within a maraging steel (type: Marage 300, 1.2709, AMS6514). Due to the large number of process variables the most influential parameters were identified first. These were energy input resulting from scanning speed, hatch distance, and layer thickness as well as the preheating of the platform. On the basis of the variation of these parameters the most abundant voids were identified and characterized by metallographic investigations. Subsequently tensile tests derived information about the influence of such voids on the mechanical properties. Based on these analyses the reasons for the generation of such voids are discussed followed by strategies in order to prevent them. This allowed for the well-aimed optimization of the processing parameters resulting in a nearly void-free SLM processing of such maraging steel parts.