Three-phase cemented hard material

摘要

A novel three-phase cemented hard material contains, apart from an iron group metal binder phase and a hexagonal hard material phase, a face-centred cubic hard material phase consisting of a mixed carbide of 70-90 (preferably 80) mol% TaC and 30-10 (preferably 20) mol% HfC and/or ZrC. Preferably, the cemented carbide contains 1-40 vol.% mixed carbide phase (preferably pre-formed by diffusion annealing at 2000 deg C) and up to 22 vol.% metal binder phase. Also claimed is a metal machining tool insert consisting of the above cemented hard material.