The fused filament fabrication (FFF) process is widely used in both industrial and private applications. Reasons for this are the simple handling, the wide range of materials, a cost-effective system technology and the uncomplicated maintenance. In expanding the material range to metals, production is very flexible allowing individual parts or small series.
In the metallic Fused Filament Fabrication (FFF) process, the material to be processed is stored on spools as filament (= wire) with a typical diameter of 1.75 mm or 2.85 mm. In this process, the filament consists of metal powder and a polymer mixture that melts at 150 °C - 200 °C. During the process, the filament is fed to a hot nozzle in the so-called print head.
Here, it is melted and extruded through the nozzle opening of 0.25 mm - 1 mm. The extruded filament material is deposited along printing paths according to the target geometry. After a layer has been finished, the build platform can be lowered and the next layer is applied. This process is repeated until the part is complete. The printers have 1, 2 or up to 4 nozzles and can, therefore, print up to 4 different materials in parallel (e.g. component material, release layer, soluble support material).
The printed part is a so-called green part, consisting of the metal powder and the polymer mixture. In a further processing step (debinding) part of the polymer mixture is removed from the component. This is followed by a heat treatment step in which the remaining polymer material is burned out and the component shrinks to 95 - 99 % of the materials relative density.
For information on the FFF process or discussions on joint project topics, please contact us. We look forward to working with you!
Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM
