| Abstract Scope |
Beam-based additive manufacturing has the potential to redefine ceramic processing for extreme applications—starting with tungsten carbide (WC). Long considered unprintable due to its ultra-high melting point (~2870 °C), extreme stiffness (~600 GPa), and low thermal expansion, WC has largely been viewed as incompatible with melt based AM technologies. However, in this study, we successfully fabricated WC using laser direct energy deposition (L-DED). The rapid cooling inherent to L-DED promoted non-equilibrium solidification, leading to the formation of a finely dispersed metastable phase—likely cubic WC₁₋ₓ—with a lamellar morphology approximately 50 nm thick. This engineered microstructure produced a high Vickers hardness (VHN₁ = 2409 ± 45) and enhanced fracture resistance through crack deflection and bridging mechanisms. These results challenge the long-standing reliance on sintering methods for ceramic processing and demonstrate the feasibility of metastable phase engineering in ceramics via beam-based additive manufacturing, opening new opportunities for applications in aerospace, defense, and other extreme environments. |