Powder-based laser metal deposition (LMD) represents a future-oriented additive manufacturing process given the large number of available materials as well as the high degree of geometric freedom. These potentials are further enhanced by high build rates and a better material utilization compared to turning or milling. However, the LMD process is very complex as a result of the large number of machine and process parameters. Different thermal conditions occur during layer-by-layer buildup. Newly supplied energy due to the laser-material interaction with the newest layer is supplemented by the heat energy still stored in the solidified component, which is distributed inhomogeneously depending on material and part geometry. In order to avoid dimensional deviations and microstructural defects, the machining parameters have to be adjusted during the LMD process. The following paper presents a strategy for the efficient and process-safe buildup of thin-walled VDM Alloy 780 geometries on 316L substrates using powder-based LMD. Adaptive adjustment of parameters and monitoring of cooling times improve the dimensional accuracy of the geometry while avoiding defects. The fabricated specimens are then analyzed using optical microscopy, SEM and EDX. Porosity analysis is performed by various methods. In addition, mechanical properties are determined by tensile tests in perpendicular and parallel directions as well as by macrohardness tests.

VDM Alloy 780 is a novel Ni-based superalloy that allows for approximately 50 °C higher operating temperatures, compared to Inconel 718, without a significant decrease in mechanical properties. The age hardenable NiCoCr Alloy combines increased temperature strength with oxidation resistance, as well as improved microstructural stability due to γ′-precipitation. These advantages make it suitable for wear- and corrosion-resistant coatings that can be used in high temperature applications. However, VDM Alloy 780 has not yet been sufficiently investigated for laser metal deposition applications. A design of experiments with single tracks on 316L specimens was carried out to evaluate the influence of the process parameters on clad quality. Subsequently, the quality of the clads was evaluated by means of destructive and non-destructive testing methods, in order to verify the suitability of VDM Alloy 780 for laser metal deposition applications. The single-track experiments provide a basis for coating or additive manufacturing applications. For conveying the results, scatter plots with regression lines are presented, which illustrate the influence of specific energy density on the resulting porosity, dilution, powder efficiency, aspect ratio, width and height. Finally, the clad quality, in terms of porosity, is visualized by two process maps with different mass per unit lengths.