Investigation of metal-polymer composites manufactured by fused deposition modeling with regard to process parameters

Abstract

A comparatively new approach for the manufacturing of metal parts is the use of fused deposition modeling (FDM). Here, a metal powder filled filament is processed to manufacture components (green part). The subsequent process chain is identical to that of metal injection molding (MIM). Thus, the polymer binder is initially removed from the component (brown part). The metal particles are finally sintered in a furnace to form a pure metal component (white part/final part). The aim of this study is the investigation of the FDM process for the fabrication of metal components with regard to process parameters. This includes the consideration of material-specific parameters influencing the extrusion process. Especially, the material temperature and material behavior within the FDM nozzle are analyzed. On this basis, the mechanical properties of specimens manufactured with different nozzle sizes and strand geometries are examined. The resulting properties are used to evaluate the suitability of the specific strand-nozzle combination for processing the metal-polymer composite. In particular, the density of the components and the process reliability are important evaluation criteria. Finally, the comparison of white parts with parts manufactured in selective laser melting (SLM) shows the possibilities offered by processing metal-polymer composites in FDM.