A coated tool, such as a rotating, cutting tool, includes a tool body and a multilayer wear protection coating system. The wear protection system coats a functional surface of the tool body that is subject to wear and includes a first undoped diamond layer and a second undoped diamond layer disposed over the first undoped diamond layer. The first undoped diamond layer is electrically conductive and exhibits grain boundary conductivity from delocalized electrons. The second undoped diamond layer is electrically insulating. The first undoped diamond layer is 4-20 microns thick and is made with diamond grains whose size ranges from 4-10 nm. The first and second diamond layers are applied by chemical vapor deposition (CVD) using a hot-wire method. The wear protection system also includes an additional undoped diamond layer that is electrically insulating and is disposed between the functional surface of the tool body and the first diamond layer.

The hard coating layer includes at least a complex nitride or carbonitride layer (2) expressed by a composition formula: (Ti.sub.1-x-yAl.sub.xMe.sub.y)(C.sub.zN.sub.1-z), Me being an element selected from Si, Zr, B, V, and Cr. The average content ratio X, the average content ratio Y, and the average content ratio Z satisfy 0.60≦x.sub.avg, 0.005≦y.sub.avg≦0.10, 0≦z.sub.avg≦0.005, and 0.605≦x.sub.avg+y.sub.avg≦0.95. There are crystal grains having a cubic structure in the crystal grains constituting the complex nitride or carbonitride layer (2). A predetermined periodic content ratio change of Ti, Al and Me exists in the crystal grains having the cubic structure.

In one aspect, cutting tools are provided comprising radiation ablation regions defining at least one of refractory surface microstructures and/or nanostructures. For example, a cutting tool described herein comprises at least one cutting edge formed by intersection of a flank face and a rake face, the flank face formed of a refractory material comprising radiation ablation regions defining at least one of surface microstructures and surface nanostructures, wherein surface pore structure of the refractory material is not occluded by the surface microstructures and surface nanostructures.

In one aspect, cutting tools are provided comprising radiation ablation regions defining at least one of refractory surface microstructures and/or nanostructures. For example, a cutting tool described herein comprises at least one cutting edge formed by intersection of a flank face and a rake face, the flank face formed of a refractory material comprising radiation ablation regions defining at least one of surface microstructures and surface nanostructures, wherein surface pore structure of the refractory material is not occluded by the surface microstructures and surface nanostructures.

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 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.

In one aspect, cutting tools are provided comprising radiation ablation regions defining at least one of refractory surface microstructures and/or nanostructures. For example, a cutting tool described herein comprises at least one cutting edge formed by intersection of a flank face and a rake face, the flank face formed of a refractory material comprising radiation ablation regions defining at least one of surface microstructures and surface nanostructures, wherein surface pore structure of the refractory material is not occluded by the surface microstructures and surface nanostructures.

A cutting tool comprising a base material and a coating; wherein: the coating comprises a titanium compound layer and an a-Al.sub.2O.sub.3 layer; the a-Al.sub.2O.sub.3 layer comprises a region A1 and a region A2; the titanium compound layer comprises a region B1 and a region B2; an average particle diameter a1 of the a-Al.sub.2O.sub.3 particles in the region A1, an average particle diameter a2 of the a-Al.sub.2O.sub.3 particles in the region A2, an average particle diameter b1 of the titanium compound particles in the region B1, and an average particle diameter b2 of the titanium compound particles in the region B2 satisfy relationships represented by respective expressions 1 to 3:

0.80?a2/b2?1.27Expression 1

1.50?a1/a2?10Expression 2

1.45?b1/b2?5Expression 3

: and the average particle diameter b1 is 0.10 ?m or more and 0.50 ?m or less.

A cutting tool including a substrate at least partially coated with a coating is provided. The coating includes a ?-Al.sub.2O.sub.3 layer, wherein the ?-Al.sub.2O.sub.3 layer in a portion O1 of the ?-Al.sub.2O.sub.3 layer within 1 ?m from the bonding layer, as measured with EBSD, exhibits Schmid factors calculated for the {0001} <11-20> slip system with the normal force applied at a 45? angle to the surface normal of the ?-Al.sub.2O.sub.3 layer, wherein the Schmid factor distribution was determined and wherein >90% of the analyzed area had a Schmid factor between 0.4 and 0.5, preferably >97% of the analyzed area had a Schmid factor between 0.4 and 0.5.

The present invention is directed to a surface-coated cubic boron nitride sintered material tool including a cBN substrate and a hard coating layer formed on a surface of the cBN substrate and having an alternate laminated structure of A layer and B layer. A peak of the grain size distribution of cBN grains in the cBN sintered material is present within a range of a grain size from 0.50 to 1.00 m. The A layer has a composition of (Ti.sub.1-xAl.sub.x)N (0.4x0.7 in an atomic ratio). The B layer has a composition of (Cr.sub.1-y-zAl.sub.yM.sub.z)N (0.03y0.6 and 0z0.05 in an atomic ratio). An X-ray diffraction peak of a (200) plane is present at a position of a diffraction angle of 43.6 plus or minus 0.1 degrees, and a plastic deformation work ratio of the B layer is 0.35 to 0.50.