Influence of printing gap in fused filament fabrication of cemented carbide on thermal debinding effectiveness

Abstract

Fused Filament Fabrication (FFF) provides an efficient solution for manufacturing cemented carbide parts with complex structures. However, the printing process introduces pore structures within the green body, which can lead to debinding defects during subsequent thermal debinding. To ensure the structural integrity of printed components, this study compares and analyzes the pore structures introduced by different printing paths in high-density cemented carbide parts. A thermal debinding pressure model and experiments were used to investigate the influence of printing gaps on debinding effectiveness. Results show that different printing paths lead to variations in pore structure and porosity. Linear infill produces the densest green body, while hexagonal infill results in the highest porosity. During thermal debinding, the pores introduced by printing serve as the primary channels for binder decomposition. Longer gas transmission paths in linear infill cause significant pressure buildup at pipeline ends, exceeding the green body's strength and leading to cracking. Debinding rate results indicate that printing gaps primarily affect the debinding effectiveness of cemented carbide parts but have minimal impact on the overall debinding rate of the green body.