Alloy tool of hard metal

摘要

An alloy tool of hard metal has a working part and a non-working part. The working part is made of a hard metal containing carbide of at least a metal selected from a group of elements belonging to the groups IVa, Va and VIa of the periodic table as a basis metal of the hard phase and an iron family metal as a basis metal of the binder phase. The working part includes a region for working a work piece. The non-working part is made of a hard metal containing carbide of at least a metal selected from a group of elements belonging to the groups IVa, Va and VIa of the periodic table as a basis metal of the hard phase of the non-working part and of an iron family metal as a basis metal of the binder phase of the non-working part. A diffused junction between the working and non-working parts bonds the two parts together. The non-working part has a higher thermal expansion coefficient than the working part, whereby the non-working part, through the diffused junction, applies a residual compressive stress to the working part for an improved tool strength.