Surface layers comprising titanium-boron-nitride compounds, and process for producing them

摘要

Surface layers for sintered hard metal bodies, especially blanking dies, are proposed which comprise titanium boron oxynitride of the general formula TiBxOyNz where x = 0.30 to 0.75; y = 0.05 to 0.25 and x + y + z = 0.98 to 1.3. The production process for surface layers of this type is based on chemical vapour phase deposition and is characterised by secondary treatment of the sintered hard metal bodies, which have been pretreated in a TiCl4-N2-H2 gas mixture, in a gas atmosphere comprising TiCl4, BCl3, N2 and H2 which is admixed with from 0.005 to 0.04% by volume of H2O.