Initial CFD-based investigation of cooling gas nozzle sets for in situ component cooling for directional independent DED-Arc

Abstract The importance of additive manufacturing of metal components is increasing in industry due to new production strategies and the associated increase in cost-effectiveness. Especially for the production of small series, prototypes, or individual parts, economical production alternatives can be expected due to the near-net-shape component structure. Approaches for higher efficiency of the component cooling during the build process indicate the potential for increasing the productivity of wire arc directed energy deposition (DED-Arc). Moreover, the control of the cooling rate is of interest for the processing of materials with low thermal diffusivity such as high-alloy steels. Therefore, in situ component cooling in DED-Arc additive manufacturing using a cooling gas flow is discussed in this article. Previously, fundamental investigations upon design and process parameters have been carried out in this subject. Based on these, a selection of derived design concepts for cooling gas nozzle sets is demonstrated in the present study. These were examined by means of a CFD model (computational fluid dynamics) for the flow of cooling gas onto a plate. The performance when applied to a flat component has been both evaluated model-based with respect to the shielding gas flow and the cooling effect as well as experimentally by measuring the residual oxygen fraction in the shielding gas atmosphere for selected variants.