Additive Manufacturing of WC-10Co Hardmetals via Fused Filament Fabrication: Pathway to High Transverse Rupture Strength

Abstract

Sinter-based additive manufacturing of tungsten carbide (WC-Co) hardmetals offers a promising route for producing complex, near-net-shape components. However, non-uniform shrinkage and high porosity remain critical challenges that compromise the mechanical performance of printed WC-Co parts. In this study, WC-Co components were fabricated using Fused Filament Fabrication (FFF) with a highly metal-filled filament containing 93.5 wt.% WC-Co, corresponding to an estimated solid loading of approximately 50 vol.%. The effects of printing, debinding, and sintering parameters on porosity, densification, and mechanical properties were systematically investigated. A two-step debinding strategy enabled effective binder removal without cracking, while optimized multi-stage sintering cycles at 1430-1450 °C produced dense microstructures with porosity as low as 0.92%. The best-performing samples achieved a Vickers hardness of 1703 HV10 and a transverse rupture strength of 1750 MPa, exceeding values typically reported for conventionally processed WC-Co.