A coated cutting tool includes a substrate and a coating having at least one ?-type aluminum oxide layer. In a cross-section of the ?-type aluminum oxide layer, when an angle formed by a normal to the cross-sectional surface and a normal to a (222) plane of a particle of the ?-type aluminum oxide layer is regarded as a misorientation, and when areas of particles, each of which has a misorientation ranging from 0-90 degrees, of the ?-type aluminum oxide layer are defined as constituting 100 area %, and the areas of particles, each of which has a misorientation ranging from 0-90 degrees, of the ?-type aluminum oxide layer are divided into respective 10-degree pitches, a total Sa of the areas of particles having a misorientation ranging from 20-30 degrees, of the ?-type aluminum oxide layer is at a maximum from among totals of areas for nine divisions in respective 10-degree pitches.

A cutting tool composed of a sintered cermet body is disclosed. The body includes hard phases composed of carbide(s), nitride(s), and carbonitride(s) of metal(s) selected from metals belonging to Groups 4, 5, and 6 of the periodic table including Ti as a main component, and includes first and second hard phases, and a binding phase mainly composed of at least one of Co and Ni. The body includes first and second faces, a cutting edge located at an edge of the first and second faces, and an interior portion located at a depth of 400 m or more from the first face. When residual stresses are measured by a 2D method, stress of the first hard phase is 80 MPa or more in terms of compressive stress. Stresses of the second hard phase and the binding phase are 50 MPa to 50 Mpa in terms of compressive or tensile stress.

In one aspect, articles are described herein comprising refractory coatings employing alumina-based hybrid nanocomposite architectures. A coated article described herein comprises a substrate and a coating deposited by CVD adhered to the substrate, the coating including a composite refractory layer having a matrix phase comprising alumina and at least one particulate phase within the matrix phase, the particulate phase comprising nanoscale to submicron particles formed of at least one of an oxycarbide and oxycarbonitride of one or more metals selected from the group consisting of aluminum and Group IVB metals.

A method of selectively hardfacing a holder of a cutting tool is provided. The method includes creating a groove on an outer surface of the holder. The method also includes applying a wear resistant material within the groove of the holder to form a wear resistant layer. The method includes heat treating the holder having the wear resistant layer.

A coated cutting tool includes a body and a hard and wear resistant PVD coating on the body, wherein the body is made from a cemented carbide, cermet, ceramics, polycrystalline diamond or polycrystalline cubic boron nitride based materials. Th coating includes a first (Ti,Al)-based nitride sub-coating and a second (Ti,Al)-based nitride sub-coating. The first (Ti,Al)-based nitride sub-coating can be a single layer, and the second (Ti,Al)-based nitride sub-coating can be a laminated structure, wherein the first (Ti,Al)-based nitride sub-coating includes a (Ti.sub.1-xAl.sub.x)N.sub.z-layer where 0.1<x<0.4, 0.6<z<1.2, and wherein the second (Ti,Al)-based nitride sub-coating includes a (Ti.sub.1-x1-y1Al.sub.x1Cr.sub.y1)N.sub.z1 layer where 0.5<x1<0.75, 0.05<y1<0.2, 0.6<z1<1.2.

For producing a cylindrical surface that has a surface structure of predetermined geometry suitable for application of material by thermal spraying, a geometrically predetermined groove structure of minimal depth and width is introduced into the surface by a tool embodied as a follow-on tool in that a groove cross-section is processed successively to a final size. In order for the surface to be producible in mass production with constant quality, the groove structure is worked in such that first a base groove is introduced with a groove bottom width that is smaller than the groove bottom width of the finished groove. Subsequently, at least one flank of the base groove is processed for producing an undercut groove profile by a non-cutting action or cutting action wherein the introduced groove structure is deformed in such a way that the groove openings are constricted by upsetting deformations of material.

In one aspect, articles are described herein comprising refractory coatings employing alumina-based hybrid nanocomposite architectures. A coated article described herein comprises a substrate and a coating deposited by CVD adhered to the substrate, the coating including a composite refractory layer having a matrix phase comprising alumina and at least one particulate phase within the matrix phase, the particulate phase comprising nanoscale to submicron particles formed of at least one of an oxycarbide and oxycarbonitride of one or more metals selected from the group consisting of aluminum and Group IVB metals.

A cermet tool includes from 75-95 volume % of a hard phase and from 5-25 volume % of a binder phase. The hard phase has a first hard phase with a core portion of (Ti, Nb, Mo) (C, N) and a peripheral portion of (Ti, Nb, Mo, W) (C, N) or (Ti, Nb, Mo, W, Zr) (C, N), a second hard phase with both a core portion and a peripheral portion of (Ti, Nb, Mo, W) (C, N) or (Ti, Nb, Mo, W, Zr) (C, N), and a third hard phase of (Ti, Nb, Mo) (C, N). The ratio of Nbs/Nbi is from 0.8 to 1.2, where Nbs is a maximum Nb amount in a surface region and Nbi is an internal Nb amount in an internal region. The ratio of Ws/Wi is from 1.0 to 1.5, where Ws is a maximum W amount in the surface region and Wi is an internal W amount in the internal region. The area ratios A1, A2, and A3 of the respective hard phases are from 75 to 95 area % for A1, from 4 to 24 area % for A2, and from 1 to 24 area % for A3.

A surface-coated cutting tool of the invention is a surface-coated cutting tool in which a surface of a tool body is coated with a lower layer and an upper layer, in which at least one layer of the lower layer is made of a TiCN layer, the upper layer has an average layer thickness of 2 to 15 m and is made of an Al.sub.2O.sub.3 layer having an -type crystal structure in a chemically deposited state, and in a coincidence grain boundary distribution graph, a highest peak is present in 3 in the range of 3 to 29, a distribution ratio of 3 occupies 35 to 70% of the whole coincidence grain boundary length of 3 or more, and a coincidence grain boundary of 31 or more occupies 25 to 60% of the whole coincidence grain boundary length of 3 or more.

A method of joining a plurality of parts to form a unitary body. At least two sintered parts are provided. At least one of the sintered parts has at least one internal cavity. Each of the parts is formed of a hard metal composition of material. The at least two sintered parts are assembled into the shape of a unitary body. Each of the at least two sintered parts has a joining surface and when each joining surface is brought into contact the surfaces form a bonding interface therebetween. The assembled parts are subjected to a vacuum or gas atmosphere, without the application of external pressure, and to a temperature sufficient to fuse the at least two sintered parts together at the bonding interface to form the unitary body.