A surface-coated cutting tool has excellent welding resistance and fracturing resistance and comprises a hard coating layer, including at least a lower layer and an upper layer, formed on a surface of a cutting tool body. The lower layer is formed of one layer or two or more layers of a TiC layer, a TiN layer, a TiCN layer, a TiCO layer, and a TiCNO layer. The upper layer is found as an Al.sub.2O.sub.3 layer on a surface of the lower layer. On at least an outermost surface of the upper layer of a rake face, a zirconium oxide layer is formed in an area ratio of 30% to 70%. The Al.sub.2O.sub.3 layer on the rake face has a tensile residual stress of 10 to 200 MPa and a surface roughness Ra is 0.25 m or less.

A cutting tool according to one aspect of the present disclosure includes a substrate and a diamond layer coating the substrate. A cutting tool according to one aspect of the present disclosure includes a rake face, a flank contiguous to the rake face, and a cutting edge configured by a ridge formed by the rake face and the flank. The rake face has a first rake face and a second rake face located between the first rake face and the flank. The second rake face and a surface of the substrate located on the side of the rake face form a negative angle. The second rake face is formed at the diamond layer.

A coated cutting tool, comprising: a substrate; and a coating layer formed on the substrate, wherein the coating layer includes a lower part layer and an upper part layer formed on the lower part layer, the lower part layer has an average thickness of 2.0 m or more and 15.0 m or less, and is formed of a Ti oxycarbonitride layer including a compound having a composition represented by formula (1) below:
Ti(C.sub.1-x-yN.sub.xO.sub.y)(1)
(where, x denotes an atomic ratio of an N element based on a total of a C element, the N element, and an O element, y denotes an atomic ratio of the O element based on a total of the C element, the N element, and the O element, and 0.35x0.60 and 0.01y0.10 are satisfied),
a FWHM of a rocking curve of a plane (4,2,2) of the lower part layer, which is obtained through X-ray diffraction, is 20 or less, the upper part layer is formed of an -aluminum oxide layer having an average thickness of 1.0 m or more and 15.0 m or less, and a FWHM of a rocking curve of a plane (0,0,12) of the upper part layer, which is obtained through X-ray diffraction, is 20 or less.

A surface-coated cutting tool includes a base material and a coating covering the base material. The base material includes a rake face and a flank face. The coating includes a TiCN layer. The TiCN layer has a (422) orientation in a region d1 in the rake face. The TiCN layer has a (311) orientation in a region d2 in the flank face.

A cutting tool includes a substrate and a diamond layer that covers the substrate. The diamond layer includes a rake face and a flank continuous to the rake face. A ridgeline between the rake face and the flank forms a cutting edge. The substrate includes a top surface opposed to the rake face. When viewed in a direction perpendicular to the top surface, the rake face includes a plurality of protrusions. In a cross-section perpendicular to a direction of extension of the cutting edge, each of the plurality of protrusions includes an inclined portion and a curvature portion continuous to the inclined portion. In the cross-section, a height of the inclined portion in the direction perpendicular to the top surface increases as a distance from the cutting edge increases.

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 -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) [RSA40 (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) [RSB40 (2)] is satisfied.

A coated cutting tool, comprising: a substrate made of a cubic boron nitride-containing sintered body; and a coating layer formed on the substrate, wherein the cubic boron nitride-containing sintered body includes 65 volume % or more and 85 volume % or less of cubic boron nitride, and 15 volume % or more and 35 volume % or less of a binder phase; the cubic boron nitride is in a form of particles, the particles having an average particle size from 1.5 m or more to 4.0 m or less; the coating layer includes a lower layer, and an upper layer formed on the lower layer; the lower layer contains particles each having a composition represented by (Ti.sub.1-xAl.sub.x)N; the lower layer has an average thickness from 0.1 m or more to 1.0 m or less; the particles forming the lower layer have an average particle size from 0.01 m or more to 0.05 m or less; the upper layer contains particles each having a composition represented by (Ti.sub.1-yAl.sub.y)(C.sub.1-zN.sub.z); and the upper layer has an average thickness from 1.0 m or more to 5.0 m or less.

A tool having a cutting edge that includes a sintered body containing cubic boron nitride. The sintered body integrally and inseparably includes an inner region and a binder phase enriched layer formed on at least part of a surface of the inner region. The inner region includes: 15-90 volume % of cubic boron nitride; and 10-85 volume % of a mixture of a binder phase and impurities. The binder phase enriched layer includes: 90-100 volume % of the binder phase and impurities mixture; and 0-10 volume % of cubic boron nitride; and the binder phase contains at least one kind selected from the group consisting of: at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Al, Co, Ni and Si; and a compound of the element and at least one element selected from the group consisting of C, N, O and B.

A coated cutting tool comprising a substrate and a coating layer formed on a surface of the substrate, the coating layer including at least one -type aluminum oxide layer, wherein, in the -type aluminum oxide layer, a texture coefficient TC (2,1,10) of a (2,1,10) plane is 1.4 or more.

[00001]$\begin{array}{cc}\mathrm{TC}\left(2,1,10\right)=\frac{I\left(2,1,10\right)}{I_0\left(2,1,10\right)}.Math..Math.{\left\{\frac{1}{8}.Math..Math.\frac{I\left(h,k,l\right)}{I_0\left(h,k,l\right)}\right\}}^{-1}& \left(1\right)\end{array}$

(In formula (1), I (h,k,l) denotes a peak intensity for an (h,k,l) plane in X-ray diffraction of the -type aluminum oxide layer, I.sub.0 (h,k,l) denotes a standard diffraction intensity for an (h,k,l) plane which is indicated on a JCPDS Card No. 10-0173 for -type aluminum oxide, and (h,k,l) refers to eight crystal planes of (0,1,2), (1,0,4), (1,1,0), (1,1,3), (0,2,4), (1,1,6), (2,1,4) and (2,1,10).)

Provided is a coated cutting tool of long tool life and that affords superior machined surface quality. A coated cutting tool includes a substrate, and a coating layer formed on the substrate. The coated cutting tool includes at least one flank face, at least one rake face, and a honing section rounded and connecting the flank face and the rake face. The coating layer includes a lower layer, an intermediate layer and an upper layer, in this order from the side of the substrate. The lower layer is composed of one, or two or more Ti compound layers made up of a Ti compound of Ti and at least one element selected from the group consisting of C, N, O and B. The intermediate layer contains -type Al.sub.2O.sub.3. The upper layer contains a compound represented by following formula (1): Ti(C.sub.1-x-yN.sub.xO.sub.y) (1). An average thickness of the coating layer on the flank face side is 5.0 m more and 30.0 m or less. A first cross section positioned at a distance of up to 1 m towards the substrate, from an interface of the intermediate layer and the upper layer side, the cross section being parallel to an interface of the substrate and the lower layer, satisfies the condition represented by following expression (i): RSA40 (i). A second cross section, positioned at a distance of up to 1 m from the interface of the upper layer and the intermediate layer side towards an interface on the opposite side, the cross section being parallel to the interface of the substrate and the lower layer, satisfies the condition represented by following expression (ii): RSB (ii). The intermediate layer is exposed at least at the honing section.