WEB Improving surface roughness and mechanical properties of Maraging Steel processed by Laser Powder Bed Fusion
Tool steel processed by additive manufacturing is of interest for the fabrication of individualized tool inserts with low batch size. The functions to be integrated in these parts can be cooling channels or interfaces for thermocouples for temperature monitoring during usage. A 18-Ni 300 maraging steel was processed by Laser Powder Bed Fusion in order to investigate densification behavior, microstructure, mechanical properties and surface roughness. In the first stage, the density was improved by optimizing the process parameters via design of experiments. In the second stage, the energy input of the process parameters was adapted to decrease the welding depth and therefore to have less agglomerated partly melted particles on the surface resulting in an improvement of the downskin surface roughness Ra and Rz of 50 %. Aging significantly reduced the effect of the building orientation of the tensile samples on the elongation at break since the samples increased in strength and decreased in ductility. Furthermore, the mechanical properties were improved by solution treatment at 900 °C for 1 hour and aging at up to 2112 MPa ultimate tensile strength. The presented research was funded by the European Union and the Saxon State Government in the frame of the project WEMS++.