WEAR-RESISTANT COATINGS FOR CERMET CUTTING TOOLS

Conventional chemical vapor deposition and physical vapor deposition p rocesses for deposition of wear-resistant coatings were shown not to b e effective for improvement in service lifetime of TiC- or TiCN-based cermets with the Ni-Mo-based binder because of an active interaction o f the binder with the coatings. A new technology for deposition of chr omium-carbide-based multilayer coatings for cermet cutting tools was d eveloped. The technology includes vacuum treating a substrate and resu lts in deposition of a wear-resistant coating composed of a chromium c arbide upper layer and an Ni-based interlayer between the carbide laye r and the substrate. Substantial improvement in the wear resistance of coated cermet indexable inserts was achieved owing to the special str ucture of the coating and its unique properties. The results of examin ations of corrosion, wear, oxidation resistance as well as other prope rties of the coated cermets are presented.