A hard coating layer on a cutting tool includes at least a Ti and Al complex nitride or carbonitride layer and has an average layer thickness of 1 to 20 μm. In a case where a composition of the complex nitride or carbonitride layer is expressed by: (Ti.sub.1-xAl.sub.x)(C.sub.yN.sub.1-y), a content ratio x and a content ratio y satisfy 0.60≦x≦0.95 and 0≦y≦0.005, where x and y are in atomic ratio. Crystal grains constituting the complex nitride or carbonitride layer include cubic phase crystal grains and hexagonal phase crystal grains. An area ratio occupied by the cubic phase crystal grains is 30-80%. An average grain width W is 0.05-1.0 μm. An average aspect ratio A of the crystal grains with the cubic grain structure is 5 or less. A periodic content ratio change of Ti and Al in (Ti.sub.1-xAl.sub.x)(C.sub.yN.sub.1-y) exists in each of the cubic phase crystal grains.

A cutting implement including a metal substrate, carbide edge(s), and coating is provided. The coating is zirconium PVD (ZrCRTiNO), which provides protection against corrosion of the metal substrate. In some instances, the zirconium PVD provides protection from corrosion for at least 200 hours. A layer of carbide can be added to one or more cutting edges of the metal substrate prior to the deposition of the coating. The carbide increases the sharpness of the cutting edges and therefore increases the life or longevity of the cutting edges. Thus, a combination of zirconium PVD (ZrCRTiNO) as a coating and carbide edges on a metal substrate can increase the life of the metal substrate by providing increased hardness, sharpness, and anti-corrosive properties.

A surface-coated cutting tool has a hard coating layer on a tool body. The hard coating layer includes a (Ti.sub.1−xAl.sub.x)(C.sub.yN.sub.1−y) layer (the average amount Xavg of Al and the average amount Yavg of C satisfy 0.60≦Xavg≦0.95 and 0≦Yavg≦0.005). Crystal grains having an NaCl type face-centered cubic structure in the layer have {111} orientation, a columnar structure in which the average grain width of the individual crystal grains having an NaCl type face-centered cubic structure is 0.1 μm to 2.0 μm and the average aspect ratio is 2 to 10 is included, and in the individual crystal grains having an NaCl type face-centered cubic structure, a periodic compositional variation in Ti and Al in the composition formula: (Ti.sub.1−xAl.sub.x)(C.sub.yN.sub.1−y) is present and the difference between the average of maximum values of x and the average of minimum values thereof is 0.03 to 0.25.

Provided is a coated tool in which a hard coating layer has excellent hardness and toughness and exhibits chipping resistance and defect resistance during long-term use. The hard coating layer includes at least a layer of a complex nitride or complex carbonitride expressed by the composition formula: (Ti.sub.1-x-yAl.sub.xMe.sub.y) (C.sub.zN.sub.1-x) (here, Me is one element selected from among Si, Zr, B, V, and Cr), an average amount Xavg of Al, an average amount Yavg of Me, and an average amount Zavg of C satisfy 0.60≦Xavg, 0.005≦Yavg≦0.10, 0≦Zavg≦0.005, and 0.605≦Xavg+Yavg≦0.95, crystal grains having a cubic structure are present in crystal grains constituting the layer of a complex nitride or complex carbonitride, and in the crystal grains having a cubic structure, a predetermined periodic concentration variation of Ti, Al, and Me is present, whereby the problems are solved.

There are provided: a sintered material having an excellent wear resistance even under a high speed cutting condition; a tool using the sintered material; and a method of producing the sintered material. The sintered material includes: a first particle group including a particle having a cubic rock-salt structure represented by Al.sub.(1-x)Cr.sub.xN (formula (1)) (where x satisfies 0.2≦x≦0.8); and a second particle group including a particle of at least one first compound selected from a group consisting of oxide and oxynitride of aluminum, zirconium, yttrium, magnesium, and hafnium.

A high-pressure high-temperature, HPHT, diamond tool piece and a method of producing an HPHT diamond tool piece. At least a portion of the HPHT diamond tool piece comprises an aggregated nitrogen centre to C-nitrogen centre ratio of greater than 30%. The method includes irradiating an HPHT diamond material to introduce vacancies in the diamond crystal lattice, annealing the HPHT diamond material such that at least a portion of the HPHT diamond material comprises an aggregated nitrogen centre to C-nitrogen centre ratio of greater than 30%, and processing the HPHT diamond material to form an HPHT diamond tool piece.

A coated tool may include a base member including a first surface, and a coating layer located at least on the first surface of the base member. The coating layer may include a first layer and a second layer. The first layer may be located on the first surface and may include a titanium compound. The second layer may be contactedly located on the first layer and may include aluminum oxide. The coating layer may include a plurality of voids located side by side in the first layer in a direction along a boundary between the first layer and the second layer in a cross section orthogonal to the first surface.

A coated cutting tool comprising a substrate and a coating layer formed on a surface of the substrate, wherein: the coating layer comprises a lower layer, an intermediate layer, and an upper layer in this order from the substrate side; the lower layer comprises one or two or more Ti compound layers containing a Ti compound of Ti and an element of at least one kind selected from the group consisting of C, N, O and B, the intermediate layer comprises an α-Al.sub.2O.sub.3 layer containing α-Al.sub.2O.sub.3, and the upper layer comprises a TiCNO layer containing TiCNO; an average thickness of the coating layer is 5.0 μm or more and 30.0 μm or less; in a specific first cross section, a misorientation A satisfies a specific condition; and in a specific second cross section, a misorientation B satisfies a specific condition.

Provided is a coated cutting tool, which includes a hard coating film containing a layer (b) formed of a nitride or a carbonitride, a layer (c) which is a layered coating film formed by alternately layering a nitride or carbonitride layer (c1) that contains 55 atom % or more and 75 atom % or less of Al, Cr having a second highest content percentage, and at least Si and a nitride or carbonitride layer (c2) that contains 55 atom % or more and 75 atom % or less of Al and Ti having a second highest content percentage, each layer having a film thickness of 50 nm or less, and a layer (d) that is a nitride or carbonitride that contains, with respect to a total amount of metal elements (including metalloid elements), 55 atom % or more and 75 atom % or less of Al, Cr having a second highest content percentage.

A coated cutting tool comprising a substrate and a coating layer formed on a surface of the substrate, wherein the coating layer includes a predetermined lower layer, an intermediate layer comprising α-Al.sub.2O.sub.3, and an upper layer comprising TiCN; the lower layer, intermediate layer, and upper layer have predetermined average thicknesses; a condition represented by formula (1) [RSA≥40 (1)] is satisfied; the interface of the intermediate layer on the upper layer side has a kurtosis roughness (S.sub.ku) of more than 3.0; the interface of the intermediate layer on the upper layer side has a skewness roughness (S.sub.sk) of less than 0; and a condition represented by formula (2) [RSB≥40 (2)] is satisfied.