Structures of Tungsten Carbide Coatings Deposited by Different Spraying Techniques.

Eight different cobalt bonded tungsten carbide powders were sprayed by three different techniques: partial pressure plasma, atmospheric plasma, and JET KOTE. The sprayed coatings are characterized by their crystallographic and metallographic structures, porosity, microhardness, and roughness. Depending on the spraying technique and the gases used, in comparison with the original powder more or less significant crystallographic transformations are observed which may be connected with a decarburization mechanism.