A composite diamond body includes a diamond base material and a stable layer disposed on the diamond base material. The stable layer may have a thickness of 0.001 m or more and less than 10 m, and may include a plurality of layers. A composite diamond tool includes the composite diamond body. There are thus provided highly wear-resistant composite diamond body and composite diamond tool that are even applicable to mirror-finish planarization of a workpiece which reacts with diamond to cause the diamond to wear.

A surface coated cutting tool having surfaces including a rake face and a flank face and a cutting edge defined by a boundary portion between the rake face and the flank face includes a substrate and a coating which covers the surfaces of the substrate, the coating having a TiAlN layer having an NaCl type crystal structure, and relation of 0.65<XR0.9, 0.65<XF0.9, 0.4XE0.7, XRXE0.2, and XFXE0.2 being satisfied, with a composition of the TiAlN layer in a cutting edge region located in the cutting edge being expressed as Ti.sub.1-XEAl.sub.XEN, a composition thereof in a rake face region located in the rake face being expressed as Ti.sub.1-XRAl.sub.XRN, and a composition thereof in a flank face region located in the flank face being expressed as Ti.sub.1-XFAl.sub.XFN.

A coated cutting tool includes a substrate and a coating. The coating has an -Al.sub.2O.sub.3-multilayer of alternating sublayers of -Al.sub.2O.sub.3 and sublayers of TiCO, TiCNO, AlTiCO or AlTiCNO. The -Al.sub.2O.sub.3-multilayer includes at least 5 sublayers of -Al.sub.2O.sub.3, wherein the total thickness of the -Al.sub.2O.sub.3-multilayer is 1-15 m and wherein a period in the -Al.sub.2O.sub.3-multilayer is 50-900 nm. The -Al.sub.2O.sub.3-multilayer exhibits an XRD diffraction over a -2 scan of 20-140, wherein the relation of the intensity of the 0 0 12 diffraction peak (peak area), I(0 0 12), to the intensities of the 1 1 3 diffraction peak (peak area), I(1 1 3), the 1 1 6 diffraction peak (peak area), I(1 1 6), and the 0 2 4 diffraction peak (peak area), I(0 2 4), is I(0 0 12)/I(1 1 3)>1, I(0 0 12)/I(1 1 6)>1 and I(0 0 12)/I(0 2 4)>1.

An insert includes a first surface having a corner portion, a second surface, a third surface, and a cutting edge. The cutting edge is provided with a first cutting edge located on the corner portion and a second cutting edge adjacent to the first cutting edge, and the third surface is provided with a first portion located along the first cutting edge and a second portion located along the second cutting edge. the second portion includes a first region having a first end portion and a second end portion, and a second region having a third end portion and a fourth end portion. An inclination angle 212 at the second end portion is greater than an inclination angle 211 at the first end portion, and an inclination angle 222 at the fourth end portion is smaller than an inclination angle 221 at the third end portion.

A cutting insert according to an aspect includes a top surface and a side surface. At least a part of a ridge line where the top surface and the side surface intersects is a cutting edge. The cutting edge includes a first portion located at a corner portion, a second portion adjacent to the first portion, a third portion close to the second portion, a fourth portion close to the third portion, and a fifth portion adjacent to the fourth portion. When viewed from directly above, a curvature radius of the second portion is less than a curvature radius of the first portion, a curvature radius of the third portion is greater than the curvature radius of the first portion, and a curvature radius of the fourth portion is less than the curvature radius of the third portion.

A coated cutting tool for chip forming machining of metals includes a substrate having a surface coated with a chemical vapour deposition (CVD) coating. The coated cutting tool has a substrate coated with a coating including a layer of -Al2O3, wherein the -Al2O3 layer exhibits a dielectric loss of 106tan 0.0025, as measured with AC at 10 kHz, 100 mV at room temperature of 20 C.

A hard coating includes two first crystalline phases, and a second crystalline phase disposed between the two first crystalline phases. The two first crystalline phases each include, independently, a laminate structure having a Ti.sub.1-x1Al.sub.x1N phase having a sodium chloride-type crystal structure, and an Al.sub.x2Ti.sub.1-x2N phase having a sodium chloride-type crystal structure that are alternately stacked. An Al composition ratio x1 of the Ti.sub.1-x1Al.sub.x1N phase satisfies a relationship 0.5x10.75, and an Al composition ratio x2 of the Al.sub.x2Ti.sub.1-x2N phase satisfies a relationship 0.75<x20.95. The laminate structure includes a region in which an Al concentration periodically changes along a stacking direction of the Ti.sub.1-x1Al.sub.x1N phase and the Al.sub.x2Ti.sub.1-x2N phase. In this region, a difference between a maximum value of the Al composition ratio x2 and a minimum value of the Al composition ratio x1 is greater than 0.25. The second crystalline phase contains AlN having a wurtzite-type crystal structure.

A cutting tool comprises a base material which includes particles including a tungsten carbide (WC) as a main component, a binder phase including cobalt (Co) as a main component, and particles including a carbide or a carbonitride of at least one selected from the group consisting of Group 4a, 5a, and 6a elements, or a solid solution thereof; and a hard film formed on the base material, wherein the hard film comprises at least an alumina layer, a cubic phase free layer (CFL), in which the carbide or the carbonitride is not formed, is formed from a surface of the base material to a depth of 10 m to 50 m, and a Co content of a surface of the CFL is 80% or more of a maximum Co content of the CFL.

A coating for carbide substrates employs a nanostructured coating in conjunction with a non-nanostructured coating. The nanostructured coating is produced by the addition of a refining agent flow, particular hydrogen chloride gas, during deposition, and may be produced as multiple individual titanium and titanium-based nanostructured layers varying functional materials in a series. The combination of a nanostructured coating and non-nanostructured coating is believed to produce a cutting tool insert that exhibits longer life. Pre-treating the substrate with a mixture of compressed air and abrasive medium prior to coating the substrate and post-treating the coated substrate with a mixture of water and abrasive medium after the coating process is believed to further enhance the wear resistance and usage life of the cutting tool.

A metal cutting insert has a substrate body of cemented carbide, cermet, or ceramic and at least one cutting edge defined between a rake face and a relief face. The cutting insert has a CVD coating including a layer of aluminum titanium nitride having a cubic face centered lattice structure, represented by a formula (Al.sub.xTi.sub.1-xM.sub.y)C.sub.zN.sub.1-z wherein a stoichiometry coefficient of aluminum is 0.30<x<0.95, wherein M is at least one element selected from the group consisting of Cl and Ar, with a stoichiometry coefficient of which is 0y<0.01, and wherein a stoichiometry coefficient of carbon is 0z<0.3. The (Al.sub.xTi.sub.1-xM.sub.y)C.sub.zN.sub.1-z layer satisfies a relationship 10<|S.sub.1-S.sub.2|<500 MPa wherein S.sub.1 is the residual stress measured on the rake face, and S.sub.2 is the residual stress measured on the relief face.