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W. Lengauer et al.:
"Preparation and properties of extrusion-based 3D-printed hardmetal and cermet parts";
Talk: EuroPM2018 Congress & Exhibition, Bilbao; 10-14-2018 - 10-18-2018.

Hardmetal and cermet bodies were printed by fused-filament fabrication (FFF) and composite extrusion modelling (CEM) in an SDS (shaping - debinding - sintering) process. For FFF the filaments were prepared from hardmetal (WC-10Co) and cermet powder (Ti(C,N)-Co/Ni-based) and organic binder. The CEM feedstock consisted of WC-Co MIM powder. A 3D filament printer as well as a 3D printer working with a granulate such as used in MIM were employed to fabricate printed bodies by FFF and CEM, respectively. The solvent debinding process was performed in cyclohexane (FFF-printed bodies) or water (CEM-printed bodies). Thermal debinding of all parts was performed in a tube furnace up to a temperature of 800 °C. The pre-sintered parts were then subjected to vacuum sintering by application of conventional vacuum sintering profiles up to 1430 °C for hardmetals and up to 1460 °C for cermets. Dimensional and mass changes upon the various preparation steps as well as microstructure and porosity of the sintered bodies were investigated. While the microstructure is practically identical to that of conventionally prepared materials, some cavities are present from the printing process because of yet non-optimised printing strategy. The study shows that with the applied 3D printing techniques, hardmetal and cermet parts with innovative geometries are accessible.

3D printing, extrusion, FFF, CEM