OBERFLAECHENBESCHICHTETER GESINTERTER HARTMETALLEGIERUNGSWERKSTOFF AUF WOLFRAMKARBID-BASIS FUER SCHNEIDWERKZEUGEINSAETZE.

摘要

A surface coated tungsten carbide-base sintered hard alloy material for inserts of cutting tools, which exhibits very excellent cutting performance by virtue of excellent wear resistance and toughness thereof, when used not only in continuous cutting of steel but also in intermittent cutting of same. The sintered hard alloy material comprises: (1) a substrate having an internal portion consisting essentially of: 5 - 30 percent by weight one composite metal carbo-nitride, as a compound forming a hard dispersion phase, selected from the group consisting of (Ti, W)CN, (Ti, Nb, W)CN, (Ti, Ta, W)CN, and (Ti, Nb, Ta, W)CN; 4 - 10 percent Co as a component forming a binder phase, and the balance of WC as a component forming the hard disperse phase and inevitable impurities; the substrate having a surface portion formed with a Co-enriched layer being substantially free of the composite metal carbo-nitride; and (2) a hard surface layer coated over the surface of the substrate, comprising: an innermost layer consisting essentially of TiC, the innermost layer containing one of a W component and W and Co components diffused from the substrate; a diffusion preventing layer formed by one of a single layer of one compound selected from the group consisting of TiCN and TiN, or a double layer of both of the compounds TiCN and TiN; an inner layer consisting essentially of TiC the diffusion preventing layer preventing diffusion of one of the W component and the W and Co components; and an outer layer formed by one of a single layer of one compound selected from the group consisting of TiCO, TiCNO, and Al2O3 and a double layer of two compounds selected from same. a