VERFAHREN ZUR HERSTELLUNG EINES BESCHICHTETEN HARTMETALLSCHNEIDKOERPERS

摘要

With sintered hard-metal articles, it has surprisingly been discovered that a toughness-enhancing shell below the chemical-vapour-deposited coating can be formed by subjecting the final-sintered pressed article, before coating, to a nitrogen-gas pressure treatment at a pressure between 0.2 and 10 MPa and at a temperature between 900 and 1300 DEG C for at least 0.5 h and, following evacuation, in argon at pressures between 10 Pa and 20 kPa and at temperatures between 1000 DEG C and 1350 DEG C for longer than 0.5 h, and cooling the sintered article under a pressure between 10 Pa and 0.1 MPa.