A cutting tool includes a substrate at least partially coated with a coating, the substrate being a cemented carbide, cermet or ceramic. The coating has a layer of Ti(C,N), a layer of Al.sub.2O.sub.3 and there between a bonding layer. The Ti(C,N) layer is composed of columnar grains, wherein an average grain size D.sub.422 of the Ti(C,N) layer is 25-50 nm, and wherein the Ti(C,N) layer includes a portion B1 that is adjacent to the bonding layer. An average grain size of the Ti(C,N) grains in portion B1 is larger than the average grain size D.sub.422 in the whole Ti(C,N) layer. In the portion B1 of Ti(C,N) layer the Ti(C,N) grains has an average grain size of 130-300 nm.

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 sintered material contains hard particles composed of one or more selected from the group consisting of cubic boron nitride, Al.sub.2O.sub.3, AlON, SiAlON, TiC, TiCN, TiN, WC, and diamond, a metallic binder phase mainly composed of Co or Ni and containing at least one element selected from the group consisting of Co, Ni, Al, W, V, and Ti, and Al.sub.2O.sub.3 dispersed in the metallic binder phase.

In an embodiment, a coated tool is disclosed. The coated tool includes a base material, a first layer on the base material, and a second layer coated on the first layer. The first layer contains diamond crystals therein and has a first mean crystal size. The second layer contains diamond crystals therein and has a second mean crystal size that is smaller than the first mean crystal size. The first and the second layers contain hydrogen, and have a first hydrogen content and a second hydrogen content respectively. The second hydrogen content is larger than the first hydrogen content.

A tool for machining fiber-reinforced materials, said tool having a tool body having a particular cutting edge that has at least a main function surface and has a diamond coating applied at least to said main function surface. In order to provide a tool and a method which are especially suitable for machining fiber-reinforced materials, the surface of the diamond coating has a reduced peak height Spk of less than 0.25 m.

A sintered compact has a first material, a second material, and a third material. The first material is cubic boron nitride. The second material is a compound including zirconium. The third material is an aluminum oxide and the aluminum oxide includes a fine-particle aluminum oxide. The sintered compact has a first region in which not less than 5 volume % and not more than 50 volume % of the fine-particle aluminum oxide is dispersed in the second material. On arbitrary straight lines in the first region, an average value of continuous distances occupied by the fine-particle aluminum oxide is not more than 0.08 m and a standard deviation of the continuous distances occupied by the fine-particle aluminum oxide is not more than 0.1 m.

A sintered compact has a first material, a second material, and a third material. The first material is cubic boron nitride. The second material is a compound including zirconium. The third material is an aluminum oxide and the aluminum oxide includes a fine-particle aluminum oxide. The sintered compact has a first region in which not less than 5 volume % and not more than 50 volume % of the fine-particle aluminum oxide is dispersed in the second material. On arbitrary straight lines in the first region, an average value of continuous distances occupied by the fine-particle aluminum oxide is not more than 0.08 m and a standard deviation of the continuous distances occupied by the fine-particle aluminum oxide is not more than 0.1 m.

A coated tool is provided which is capable of inhibiting occurrence of chipping, peeling-off, or the like of a diamond layer by enhancing fracture resistance, and which has the diamond layer with high wear resistance. The coating tool is, for example, a drill having a diamond layer coated on a surface of a base material. The diamond layer has a first coating layer located close to the base material, and a second coating layer located on the first coating layer. A mean particle size of second diamond particles constituting the second coating layer is smaller than a mean particle size of first diamond particles constituting the first coating layer. The diamond layer contains hydrogen, and a hydrogen content in the second coating layer is larger than a hydrogen content in the first coating layer.

A coated tool includes a base body and a coating layer located on a surface of the base body. The coating layer contains a cubic crystal composed of at least one element selected from Group 4a, 5a and 6a elements under the periodic table, Al, Si, B, Y, and Mn, and at least one element selected from C and N. In a measurement range from 0 to 90 in a distribution of X-ray intensity on an axis in a positive pole figure for a (111) plane of the coating layer, a difference between a maximum value and a minimum value of the X-ray intensity in a range where an angle of the axis is from 30 to 90 is 10% or less of the maximum value.

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.