Growth of Tungsten Carbide Monocrystals

Abstract

Tungsten carbide monocrystals have been grown from a Co flux using a modified Czochralski technique. These crystals are about 1 cm in size, show little internal strain, and contain few Co inclusions. The highestquality crystals grow in the [OOOlJ direction with a melt composition of 16 mole% WC-84 mole% Co, a surface temperature of 1475°C, and a"pulling rate of 0.2 mm/h.

Single-Crystal Tungsten Carbide in High-Temperature In-Situ Additive Manufacturing Characterization

“…Well-formed triangular and irregular hexagonal plates of single-crystal WC were produced by the above described method. It was observed that crystal size and quality correlated well with WC concentration and cooling rates as previously reported in literature, [3,6] with higher concentrations of WC producing a greater number of smaller crystals, while lower concentrations produced fewer but larger crystals. It was also observed that slower cooling rates tended to produce larger crystals, but these crystals exhibited a greater number of defects and produced a greater number of polycrystalline clusters.…”

“…The starting growth charge consisted of tungsten carbide powder (Kennemetal #SCNC022) and cobalt powder (Sigma-Aldrich #266647). Cobalt metal was chosen as the flux due to its ability to dissolve higher amounts of WC at lower temperatures [3] and its solubility in HCl to facilitate the crystal recovery process. A total of 8 growth runs were prepared by weighing out the powders into 100 gram batches with WC concentrations of 15, 20, and 30 mole %.…”

High temperature deformation behavior of cemented carbide cutting tools

“…Further attempts to improve 12 this technique, to eliminate the included material, proved 13 unsuccessful.…”