Alumina and zircon refractory ceramic molds fabrication by additive methods for metal alloys casting

Traditional processes for the foundry molds fabrication need numerous and rather time consuming steps. These processes are not really adapted to small series or prototypes. The research project exposed in this contribution proposes an alternative method combining the advantages of molding (free formulation of metal alloys, economy on material and on time of machining) with those of the additive processes (short steps between 3D-model and final product, very complex geometries available). For short series the selective laser melting process (SLM) allows the building of molds in a very short time compared to the traditional investment casting method. This technique also permits the unique advantage to control the design of the shell thickness and structure in order to have a better control of the thermal fluxes during metal cooling. This would potentially ensure a better control of the casting defaults. In this presentation, molds built with alumina and zircon as raw materials will be presented. Two metallic alloys have been tested in order to validate alumina and zircon as mold materials; the first, AlCu4MgSi chosen as low melting point alloy reference and the second, stainless steel 316L, as high melting point alloy referenc