Abstract: The present invention relates to a coated cutting tool equipped with a substrate and a coating formed on the substrate. The coating includes: a compound formed from elements Al and/or Cr and at least one element selected from a group consisting of carbon, nitrogen, oxygen, and boron; and chlorine.

Abstract: The present invention provides a surface-coated cutting tool comprising a coating film on a base, while the coating film comprises a hard layer constituted of a compound selected from a nitride, a carbonitride, an oxynitride and a carboxynitride of at least one primary element selected from a group consisting of the metals belonging to the groups 4a, 5a and 6a of the periodic table as well as B, Al and Si, and the hard layer satisfies the following: (a) (hmax?hf)/hmax is at least 0.2 and not more than 0.7, assuming that hmax represents the maximum indentation depth and hf represents the indentation depth (dent depth) after unloading in a hardness test according to nanoindentation, (b) the thickness of the hard layer is at least 0.5 ?m and not more than 15 ?m, and (c) the hardness according to nanoindentation is at least 20 GPa and not more than 80 GPa.

Abstract: A diamond-coated hard material having a diamond- or diamond-like carbon coated layer with a high bonding strength to a substrate is provided. The coated hard material comprising a diamond- and/or diamond-like carbon-coating layer formed on the surface of a hard material, i.e. substrate is characterized in that (I) (1) microscopic roughness is present on the surface of the substrate and (2) protrusive parts thereof are defined by the surface roughness Rmax within a range of 1.0 to 30 .mu.m in a standard length when the standard length is 50 .mu.m in the interface of the diamond- and/or diamond-like carbon coated layer and the substrate, and (II) (1) microscopic roughness is present on the surface of the substrate, (2) at least one protrusive part is present in a standard length when the standard length is 10 .mu.

Abstract: This invention relates to a diamond-coated hard material and a process for the production of the same. The feature of the diamond-coated hard material consists in that in a diamond-coated hard material comprising a substrate of a tungsten carbide-based cemented carbide having a diamond-coated layer provided on the surface of the substrate, a surface-modified layer containing no binder phase or containing a binder phase in a proportion of less than in the interior part of the substrate is present on the outermost surface of the substrate. This hard material can be produced by converting the substrate material into a sintered or heat treated surface or skin and then coating with diamond. The diamond-coated hard material of the present invention has such a high wear resistance and excellent bonding strength to the substrate that it can favorably be applied to various tools, parts, grinding wheels, etc.

Abstract: An object of the present invention is to provide a diamond-coated hard material having a high bonding strength to a substrate and a diamond-coated throwaway insert capable of cutting various light alloys such as Al-Si alloys at a high cutting rate for a long time. This object can effectively be attained by a diamond-coated hard material comprising a sintered body consisting of Si.sub.3 N.sub.4 as a predominant component, at least a part of the sintered body having a sintered surface at least a part of which is coated with diamond and a diamond-coated throwaway insert having a diamond- or diamond-like carbon-coated layer with a thickness of 0.1 to 200 .mu.m, deposited from gaseous phase, on the surface of a substrate consisting of Si.sub.3 N.sub.4, as a predominant component, in which the surface state of the substrate is maintained as sintered and a part or whole of the sintered surface is coated with the diamond- or diamond-like carbon-coated layer.

Abstract: A surface-coated hard material for a cutting tool or wear resistance tool is provided which is excellent in wear resistance, deposition resistance and breakage resistance and exhibits good cutting performances for a long time, as a cutting tool or a wear resistance tool, in not only a low speed cutting but also a high speed cutting, and in which a layer consisting of a carbide, nitride or carbonitride of Ti, Zr or Hf and a layer consisting of a carbide, nitride or carbonitride of Al are alternately laminated to form at least 10 hard coating layers.

Abstract: A drill bit of a diamond-coated sintered body has a substrate mainly composed of Si.sub.3 N.sub.4 or SiC. At least a wear portion of the bit is coated with a diamond layer. If the bit is of the throw-away kind, an insert is removably secured to a shank. At least the insert or a wear portion thereof is coated with a diamond layer. The sintered body contains a prescribed amount of a sintering assistant or aid selected from MgO, Y.sub.2 O.sub.3 and the like. The diamond coating layer has a thickness of at least 0.1 .mu.m.