Conventional hard metal coatings on WC/Co metalloceramics are treated
at elevated temperatures by cobalt diffusion. That could prevent apply
ing suitable barrier sublayers. The paper presents results on the poss
ibility tungsten carbide (WC) and carbonitrides (WCxNy) CVD layers to
be used as a barrier against Co diffusion.. The coatings were prepared
using two CVD methods: direct growing of WC or WCxNy and carborizatio
n/carbonitridization of W films. The level of diffused Co was investig
ated by X-ray microprobe technics, Auger electron spectrometry and dir
ect layer by layer spectral analysis in the hollow cathode glow discha
rge method. Results show that WC and WCxNy coatings are prospective fo
r preventing diffusion interaction between the substrate and the funct
ional coatings. (C) 1998 Elsevier Science B.V. All rights reserved.