3D hybrid-material processing in selective laser melting: implementation of a selective coating system

In 3D printing, the highest degree of freedom in design is achieved using powder bed techniques such as selective laser melting (SLM). The current disadvantage of this technique is that it allows only for the production of single material parts using standard setups. However, advanced designs and local requirements are met best by a tailored arrangement of different materials. A key challenge for multi-material powder bed SLM is the selective deposition of the materials in each layer. In this paper, a hybrid-material powder coating system for SLM machines was developed and installed in a SLM125 Realizer machine. First, the generic classification for the material arrangements in additive manufactured parts is reviewed and extended. Furthermore, existing principles and procedures used for multi-material coating, especially focusing on contamination-free processes are examined. Based on this, an advanced coating mechanism is developed and proof of principle is provided.