12070-13-2

black hexagonal, a=0.29982 nm, c=0.4722nm; can be prepared by heating tungsten and carbon in the presence of hydrogen at high temperatures; hardness approaches that of diamond; brittle; used in hard metals, and as a 99.5% pure sputtering target to produce wear-resistant films and semiconductor films [KIR83] [CIC73] [CER91] [CRC10]

Black. Resistant to oxidation in air up to 700°C. Corrosion resistant to Mo.

Either of two carbides (W₂C and WC) produced by heating powdered tungsten with carbon. The carbides are extremely hard and are used in industry to make cutting tools or as an abrasive. WC has a very high melting point (2770°C) and will conduct electricity. W₂C also has a very high melting point (2780°C) but is a less efficient conductor of electricity. It is very resistant to chemical attack and behaves in a manner very similar to that of tungsten. It is strongly attacked by chlorine to give tungsten hexachloride, WCl₆.