Surface adsorption phenomenon during the preparation process of nano WC and ultrafine cemented carbide

The surface adsorption phenomena during the preparation process of nano tungsten carbide and WC-10Co-0.35VC-0.45Cr(3)C(2) ultrafine cemented carbide were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDXS). It is shown that new phases are formed on the surface of nano tungsten carbide and the sinter skin of ultrafine cemented carbide due to the interaction among the impurity elements from the furnace or the impurity elements and-alloy elements, accompanied with the change of the surface properties. Nevertheless, the formation of impurity elements containing phases on the sinter skin of cemented carbide does not result in any evidently abnormity in the inner microstructure. The tungsten carbide grains in cemented carbide are homogeneously distributed and well crystallized with an average grain size of 200-300 nm. (c) 2006 Elsevier Ltd. All rights reserved.