In this project, OBE and CEA are in charge of the development and characterization of an hybrid DMLS/MIM demonstrator, by measuring the mechanical properties of the DMLS/MIM interface. OBE produced four batches of a MIM feedstock based on different standard 316L powders, three-powder gas atomized and one water atomize. See previous news.
From OBE results and CEA characterizations carried out on the four powders, CEA determined the powder specifications to ensuring the powder compatibility with the DMLS and MIM process, see table 1. The aspect ratio is the most critical requirement.
Based on this study, water atomized powder has been set aside and some hybrid tensile bars have been printed with the three- gas atomized powders. The MIM preform has been produced by OBE and the DMLS part printed by CEA. The figure 1 shows the three hybrid tensile bars carried out from the three gas atomized powder.
The interface observed after etching, figure 2, shows the difference of the microstructure between each part. Granular for the MIM part, charateristic of free sintering, and laminar for the DLMS part, characteristic of the welded layers. The results show that hybrid MIM/DMLS parts can be successfully manufactured. These first prototypes presented here can be used as an excellent cornerstone for further investigations in WP4 of the MAESTRO project where the properties of the MIM/DMLS interface will be investigated.