A surface-coated cutting tool includes a coating layer having a laminated structure that includes first sublayers and second sublayers having a cubic crystal structure and has an average thickness of 0.5 to 8 m, the bottommost and topmost sublayers being both first sublayers; the first sublayer has an average thickness of 0.1 to 2 m and a composition (Al.sub.1xCr.sub.x)N, where x=0.20 to the second sublayer has an average thickness of 0.1 to 2 m, has a composition (Al.sub.1-a-bCr.sub.aSi.sub.b)N where a=0.20 to 0.60, b=0.01 to 0.20, and has a repeated variation in Si content with an average interval of 1 to 100 nm between local minima and local maxima, the average local maximum and minimum are each within a specific range; and the diffraction peaks of the 111 and 200 diffraction peaks each have a predetermined full width at half maximum and a peak intensity.

A surface-coated cutting tool including at least a TiAlCN layer, in which the layer is expressed by a composition formula: (Ti.sub.1-XAl.sub.X)(C.sub.YN.sub.1-Y), an average content ratio X of Al and an average content ratio Y of C (here, X and Y are atomic ratios) satisfy 0.60X0.95 and 0Y0.005, respectively, an average content ratio Z of Cl in the total amount of atoms configuring the TiAlCN phase (here, Z is an atomic ratio) satisfies 0.0001Z0.004, plane spacings d(111) and d(200) are respectively calculated from X-ray diffraction spectra of (111) plane and (200) plane of crystal grains having a NaCl type face-centered cubic structure in the TiAlCN layer measured by using an X-ray diffraction device, and an absolute value A=|A(111)A(200)| defined as A(111)=3.sup.1/2d(111) and A(200)=2d(200) satisfies 0.007 A0.05.

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. The 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.

Provided is a surface-coated cutting tool including a base material and a coating including a super-multilayer-structure layer where A layers and B layers different from the A layers in composition are alternately laminated. The super-multilayer-structure layer includes an X area and a Y area those are alternately repeated. In the X area, A layers having a thickness A.sub.X and B layers having a thickness B.sub.X are alternately laminated. In the Y area, A layers having a thickness A.sub.Y and B layers having a thickness B.sub.Y are alternately laminated. The thickness A.sub.X is larger than the thickness A.sub.Y, and the thickness B.sub.X is smaller than the thickness B.sub.Y. Each of the A layers and the B layers comprising one or more elements selected from a group consisting of Ti, Al, Cr, Si, Ta, Nb, and W, and one or more elements selected from a group consisting of C and N.

A cutting tool includes a base material, and a coating film covering the base material in contact with the base material. The base material is a cubic boron nitride sintered material. The coating film is a ceramic. An amount of oxygen in the coating film is less than or equal to 0.040 mass percent.

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.

A coated cutting tool includes a substrate of cemented carbide, cermet, ceramics, steel or cubic boron nitride and a multi-layered wear resistant coating. The multi-layered wear resistant coating has a total thickness from 5 to 25 m and includes refractory coating layers deposited by chemical vapour deposition (CVD) or moderate temperature chemical vapour deposition (MT-CVD). The multi-layered wear resistant coating has at least one pair of layers (a) and (b), with layer (b) being deposited immediately on top of layer (a). Layer (a) is a layer of aluminium nitride having hexagonal crystal structure (h-AlN) and a thickness from 10 nm to 750 nm. Layer (b) is a layer of titanium aluminium nitride or titanium aluminium carbonitride represented by the general formula Ti.sub.1-xAl.sub.xC.sub.yN.sub.z with 0.4x0.95, 0y0.10 and 0.85z1.15, having a thickness from 0.5 m to 15 m, and at least 90% of the Ti.sub.1-xAl.sub.xC.sub.yN.sub.z of layer (b) has a face-centered cubic (fcc) crystal structure.

A coated cutting tool comprising a substrate and a coating layer formed on a surface of the substrate, the coating layer including an alternating laminate structure in which two or more compound layers of each of two or three or more kinds, each kind having a different composition, are laminated in an alternating manner, wherein: the alternating laminate structure is constituted by: a compound layer containing a compound having a composition represented by formula (1) below:

(Ti.sub.xM.sub.ySi.sub.z)N(1)

[wherein M denotes an element of at least one kind selected from the group consisting of Zr, Hf, V, Nb, Ta, Cr, Mo, W and Al, x denotes an atomic ratio of Ti based on a total of Ti, an element denoted by M and Si, y denotes an atomic ratio of the element denoted by M based on a total of Ti, the element denoted by M and Si, z denotes an atomic ratio of Si based on a total of Ti, the element denoted by M and Si, x satisfies 0.20x0.50, y satisfies 0.20y0.50, z satisfies 0.03z0.30, and x, y and z satisfy x+y+z=1]; and a compound layer containing a compound having a composition represented by formula (2) below:

(Ti.sub.aM.sub.bSi.sub.c)N(2)

[wherein M denotes an element of at least one kind selected from the group consisting of Zr, Hf, V, Nb, Ta, Cr, Mo, W and Al, a denotes an atomic ratio of Ti based on a total of Ti, an element denoted by M and Si, b denotes an atomic ratio of the element denoted by M based on a total of Ti, the element denoted by M and Si, c denotes an atomic ratio of Si based on a total of Ti, the element denoted by M and Si, a satisfies 0.20a0.49, b satisfies 0.21b0.50, c satisfies 0.04c0.30, and a, b and c satisfy a+b+c=1]; an absolute value of a difference between an amount of a specific metal element contained in a compound layer which constitutes the alternating laminate structure based on an amount of all the metal elements contained therein and an amount of the specific metal element contained in another compound layer which is adjacent to the compound layer and which constitutes the alternating laminate structure based on an amount of all the metal elements contained therein, is more than 0 atom % and less than 5 atom %; and an average thickness of each of the compound layers is from 1 nm or more to 50 nm or less, and an average thickness of the alternating laminate structure is from 1.0 m or more to 15.0 m or less.

A cutting edge tip of a cubic boron nitride sintered body has improved joint strength to a substrate of a cemented carbide. A cutting edge tip of a cubic boron nitride sintered body has improved crater wear resistance. A tool 10 of the present invention includes a substrate 12 of a cemented carbide and a cutting edge tip 14 of a cubic boron nitride sintered body joined to the substrate 12. The cutting edge tip 14 has a thickness covering an upper surface 12a to a lower surface 12b of the substrate 12. The cubic boron nitride sintered body contains 50 volume % or more and 95 volume % or less of cubic boron nitride and 5 volume % or more and 50 volume % or less of a binder phase. The cubic boron nitride has an average grain size of 1.0 m or more and 6.0 m or less.

A coated tool disclosure includes a base body and a coating layer. The coating layer includes crystals having a cubic structure. The coating layer has a striped structure in cross-sectional observation by a transmission electron microscope. The striped structure has two layers alternately located in a thickness direction. The two layers contain Si and at least one metal element. The two layers each contain crystals having the cubic structure. When a lattice constant of a crystal having the cubic structure in one layer of the two layers is referred to as a first lattice constant and a lattice constant of a crystal having a cubic structure in the other layer of the two layers is referred to as a second lattice constant, a difference between a magnitude of the first lattice constant and a magnitude of the second lattice constant is greater than 0% and 0.1% or less.