Synthesis of W₂C by Reactive Hot Pressing and Its Mechanical Properties

Abstract

Tungsten hemicarbide W₂C with no or small amounts of W or WC was prepared by reaction-sintering from W and WC powders using a resistance-heated hot-pressing technique called spark plasma sintering. The product phases, density, microstructure, elastic moduli, hardness, and fracture toughness of the sintered bodies were determined. The stable region of the W₂C phase had a narrow carbon content below 1860°C. W₂C had a Poisson’s ratio of 0.286, and its Young’s modulus at zero porosity was determined to be 444 GPa from the true density and bulk density dependence. These values suggest that W₂C has elastic deformation behavior similar to that of W.