Lithographic Additive Manufacturing Of Metal-based Suspensions

The novel lithography-based additive manufacturing process suitable for the processing of metals comprises a photo-reactive metal suspension, which is cured by selectively exposing it to light. The photo-reactive suspension is loaded with a commercially available 316L powder up to a solid loading of 50 vol%. After printing the green parts, an additional thermal treatment is required for the parts to gain their final metallic properties. This thermal treatment—similar to the thermal treatment used for Metal Injection Molding (MIM)—eliminates polymer binder and is referred to as debinding. After the debinding stage the structure can be sintered up to 98.5% of the theoretical density of 316L. Using a vat polymerization process, highly complex parts made of 316L could be manufactured showing a good geometrical accuracy and very low surface roughness. Also the mechanical properties of the additive manufacturing structure are comparable to conventionally manufactured 316L.