Optimization of Debinding and Sintering in Metal Freeforming with the ARBURG Freeformer by Variation of Process Parameters and Part Design

The ARBURG freeformer has been enabled to use metal feedstocks known from the metal injection molding (MIM) sector to additively manufacture green parts. By debinding and sintering these green parts, it is possible to economically produce metal components. In this paper, existing guidelines of sintering and additive manufacturing (AM) processes are compared to derive optimized part design and process parameters for the sinter-based process chain. Water-soluble support structures to maximize the freedom of design for metal parts are introduced. A variety of printing strategies for wall thickness, infill structures, and densities are evaluated according to their performance in debinding and sintering, as well as compressive strength, shrinkage behavior, and dimensional tolerance of the sintered part. A reduction in layer height from 0.2 to 0.125 mm has been achieved with a 0.2 mm nozzle to optimize the surface quality of the printed parts.