Tungsten Boride, WB₂

Tungsten Boride, WB₂, is produced when a mixture containing 4 grams of tungsten and 0.2 gram of boron is heated in an electric furnace, or when an electric arc is passed between electrodes, made by pressing together finely powdered boron and tungsten, in a vacuum electric furnace. The product is silvery and metallic on fracture, and consists of microscopic octahedral crystals. The boride is brittle, of hardness 8 and of density, according to Tucker and Moody, 9.6; Wedekind found the density at 20° C. to be 10.77. It is slowly attacked by concentrated acids, more readily by aqua regia. Chlorine decomposes it at 100° C. It readily dissolves in a fused mixture of sodium carbonate and potassium nitrate.