Abstract
The WC-β-Co alloys with different compositions were in vacuum sintered, and subsequently heated mainly in N2 at 1473-1723 K for 1.8-43.2 ks to form a hard phase layer on the specimen surface. The formation of hard phase layer was suggested by the authors' previous results.
It was found that the hard phase layer showed a smooth outersurface, when the alloy was heated in a solid state; The layer grew from the surface to the inside; The thickness of layer increased with heating temperature and time, N2 pressure, f and Co contents; The relation, xoc√t, was held, where x and t are the thickness and heating time, respectively.
