Physical properties of Tungsten Carbide

Tungsten carbide is high melting, 2,870 °C (5,200 °F), extremely hard 8.5–9.0 Mohs scale at 22 GPa Vickers hardness (Vickers Hardness number = 2242) with low electrical resistivity (1.7–2.2×10⁻⁷ Ohm·m), comparable with metals (e.g. vanadium1.99×10⁻⁷ Ohm·m).

WC is readily wetted by both molten nickel and cobalt nikel and cobalt. Investigation of the phase diagram of the W-C-Co system shows that WC and Co form a pseudo binary eutectic. The phase diagram also shows that there are so-called η-carbides with composition (W,Co)₆C that can be formed and the fact that these phases are brittle is the reason why control of the carbon content in WC-Co hard metals is important.