Abstract: A coated body consisting of a substrate that can be decarburized during a carbide, nitride or carbonitride coating process comprising a first (innermost) carbon diffusion retarding coating of MetCO, MetCON, MetON adjacent to the substrate and a second (next innermost) wear resistant coating of MetC, MetN and/or MetCN, where Met is Ti, Hf, V, Zr, Si, B or other metals of subgroup 3-7 of the periodic table of the elements, or a mixture thereof. The intermediate coating has been found beneficial in order to reduce or even eliminate the formation of eta phase in the substrate.

Abstract: The present invention relates to a sintered body for chip forming machining containing at least one hard constituent comprising a carbide, nitride and/or carbonitride of a metal of group IVB, VB or VIB in the periodical system and a binder metal based upon Co, No and/or Fe, in which the body comprises a core containing eta-phase or an intermediate phase, substantially free of carbon and/or nitrogen surrounded by a hard constituent- and binder phase-containing surface zone, free of said eta-phase or intermediate phase.

Abstract: An improvement in a cemented hard metal is disclosed. A molybdenum-tungsten-carbonitride is disclosed having the structure of tungsten carbide wherein the molybdenum and/or tungsten are at least partly substituted for by a metal selected from the group consisting of Cr, Nb, Ta, V, Re and mixtures thereof. The carbonitride may be mixed with a binder metal and sintered in a conventional manner to form a dense, substantially pore-free material.