Metal Additive Manufacturing Conference - MAMC 2022

Lithography-based metal additive manufacturing (LMM) is a novel additive manufacturing technology, which enables the production of functional metal components with smooth surface aesthetics, high feature resolutions and complex shapes, unmatched by other metal additive manufacturing technologies. The LMM printer fabricates so-called green parts applying the principle of photopolymerization with DLP-based stereolithography. The printed green parts comprise of the metal powder held in shape by the photopolymer-based binder system. During the layer-wise printing process, metal powder is homogeneously dispersed in a light-sensitive resin which solidifies by a polymerization reaction. As the fabrication process does not require supporting structures, unlike typical stereolithography processes, the parts can be cleaned without difficulty with solvent solution without damaging the surface. To gain the final metallic properties, the green parts require a debinding and sintering step, similarly to other sinter-based methods, such as Metal Injection Molding (MIM).
After the post-processing, the relative density, microstructure and mechanical properties of the parts produced by the LMM technique are equivalent to the properties of MIM fabricated components. Sintered 316L stainless steel parts can reach > 98% of the relative density with > 500 MPa tensile strength. Typical Ra surface roughness values for as-sintered parts (without any surface treatment) are <5 µm independent of printing direction.
LMM is developed as a complementary technology for a MIM mass production to support quick prototyping and fast design iteration steps, while also enabling the small-scale production of complex shapes which would be too difficult for MIM. Thus, LMM can help the MIM producers to facilitate efficient customer support and product development and can also be used as a standalone production technique for wide range of functional metal components.