Synthesis of WC-W₂C Composite Ceramics by Reactive Resistance-Heated Hot Pressing and their Mechanical Properties

Abstract

Dense WC-W₂C composite ceramics were prepared by reactive resistance-heated hot-pressing of WC-W powder mixtures. Product W₂C phase in the ceramics was increased with W content in the mixtures, and a single W₂C phase ceramic was obtained at 31.1 mol%C. Increasing W₂C phase improved sinterability, decreased hardness, Young's modulus and fracture toughness, and increased Poisson's ratio. A slightly W₂C-containing ceramic, W-48.7 mol% C, has almost the same mechanical properties as WC, Young's modulus 673 GPa, Vickers hardness 25.3 GPa, fracture toughness 5.8 MPa m^1/2, and Poisson's ratio 0.22, and is superior in sinterability to WC.