Fused filament fabrication process window for good interlayer bonding: Application to highly filled polymers in metallic powder*

Extending the fused filament fabrication process to highly filled thermoplastics in metallic powder used metal injection molding is a promising method produce small series. However, lack of adhesion between deposited filaments can cause ruptures during or debinding process. We designed simple device measure shear strength required tear off on substrate. This makes it possible quickly determine processing window for good welding filaments. developed 2D thermal simulation using finite difference while integrating enthalpy fusion and crystallization kinetics material. then fitted measurements at depths 0.45 0.75 mm under substrate surface small-diameter thermocouples. Simulation results highlight key role contact resistance evolution interface temperature. provides essential information explain that be determined experimentally. The characteristic time macromolecule diffusion was by rheological found too play bonding simulated cooling rates studied methodology introduced this work improve polymers interlayer adhesion, but other unfilled polymers.