A coated cutting tool which has, on a surface of a substrate, a layer A of a face-centered cubic lattice structure which is a nitride or carbonitride containing 50 atom % or more of Al, 20 atom % or more of Cr, 85 atom % or more of Al and Cr, and 4 atom % or more and 15 atom % or less of Si, and a layer B provided on the layer A. The layer B is a nitride or carbon nitride which contains 70 atom % or more and 90 atom % or less of Ti, 5 atom % or more and 20 atom % or less of Si, and 1 atom % or more and 10 atom % or less of Nb or Cr in terms of a total amount of metal (including metalloid) elements, and has the face-centered cubic lattice structure.

A coated cutting tool, comprising: a substrate; and a coating layer formed on a surface of the substrate, wherein the coating layer includes a lower layer and an upper layer in this order from a substrate side toward a surface side, and the upper layer is formed on a surface of the lower layer, the lower layer contains a compound having a composition represented by (Al.sub.xTi.sub.1-x)N, an average thickness of the lower layer is 1.0 μm or more and 15.0 μm or less, the upper layer contains an α-Al.sub.2O.sub.3 layer containing α-Al.sub.2O.sub.3, an average thickness of the upper layer is 0.5 μm or more and 15.0 μm or less, and in grains of the α-Al.sub.2O.sub.3 layer, a proportion of grains of which a grain size is 0.05 μm or more and less than 0.5 μm is 50% by area or more and 80% by area or less.

A coating includes a first base layer including a nitride of at least Al and Cr, a second base layer including a nitride of at least Al and Cr overlying the first base layer, and an outermost indicator layer overlying the second base layer. The first base layer has a positive residual compressive stress gradient. The second base layer has substantially constant residual compressive stresses. The outermost indicator layer includes a nitride of Si and Me, wherein Me is at least one of Ti, Zr, Hf, and Cr. The outermost indicator layer has residual compressive stresses that are less than the residual compressive stresses of the second base layer.

A surface-coated cutting tool according to the present invention includes a tool body and a hard coating layer including a complex carbonitride layer containing a small amount of chlorine and (Ti.sub.(1-x)Zr.sub.xyHf.sub.x(1-y))(N.sub.(1-z)C.sub.z) (0.10≤x≤0.90, 0<y≤1.0, 0.08<z<0.60), a ZrHf and C content ratios in cycles, a cycle distance between a maximum ZrHf content point and an adjacent minimum ZrHf content point and a cycle distance between a maximum C content point and an adjacent minimum C content point are 5 to 100 nm, an average value of content ratio differences Δx and Δz is 0.02 or more, a distance between the maximum ZrHf content point and the maximum C content point is ⅕ or less of the distance between a maximum content point and a minimum content point of adjacent ZrHf components, and a composition fluctuation structure is 10% or more.

A surface-coated cutting tool including a tool substrate containing WC crystal grains and insulating grains, and a coating layer composed of a multiple nitride of Ti, Al, and V and disposed on the surface of the tool substrate. The multiple nitride is represented by a compositional formula: Ti.sub.aAl.sub.bV.sub.cN satisfying the following relations:
0.25≤a≤0.35,
0.64≤b≤0.74,
0<c≤0.06, and
a+b+c=1
wherein each of a, b, and c represents an atomic proportion. The coating layer is characterized by exhibiting a peak attributed to a hexagonal crystal phase and a peak attributed to a cubic crystal phase as observed through X-ray diffractometry.

Provided is a surface-coated cutting tool including a complex carbonitride layer on the tool body, wherein a ratio of crystal grains having a NaCl type face-centered cubic structure is 80 area % or more, x.sub.avg and y.sub.avg satisfy 0.60≤x.sub.avg≤0.90 and 0.000≤y.sub.avg≤0.050, respectively, a composition of the Ti—Al complex carbonitride layer being represented by (Ti.sub.1-xAl.sub.x)(C.sub.yN.sub.1-y), the x.sub.avg being an average of x that is an Al content in a total content of Al and Ti, and the y.sub.avg being an average of y that is a C content in a total content of C and N, the crystal grains having the NaCl type face-centered cubic structure include crystal grains in which the x repeatedly increases and decreases, the crystal grains include 10 to 40 area % of crystal grains G.sub.1 having an average distance of 40 to 160 nm and crystal grains G.sub.s having an average distance of 1 to 7 nm.

A surface coated cutting tool includes a tool substrate; and a hard coating layer on the tool substrate. The hard coating layer includes, in sequence from the tool substrate toward a surface of the tool, a titanium carbonitride inner layer, a titanium nitride lower intermediate layer, a titanium carbonitride upper intermediate layer, a titanium oxycarbonitride bonding auxiliary layer, and an aluminum oxide outer layer. Titanium nitride grain boundaries in the lower intermediate layer and titanium carbonitride grain boundaries in the upper intermediate layer are continuous from titanium carbonitride grain boundaries in the inner layer. The texture coefficient TC(422) of titanium carbonitride in the inner layer and the upper intermediate layer is 3.0 or more, and the texture coefficient TC(0 0 12) of α-aluminum oxide in the outer layer is 5.0 or more.

A coated tool according to the present disclosure comprises a base body and a coating film. The base body contains a plurality of boron nitride particles. The coating film is located on the base body. Furthermore, the coating film includes a hard layer and a metal layer other than a simple substance of Ti, Zr, V, Cr, Ta, Nb, Hf, and Al located between the base body and the hard layer.

A cemented carbide may include a hard phase including W and C, and a binder phase including cubic Co. The binder phase may include Zr. The Co may include a lattice constant of more than 3.5575 Å and not more than 3.5600 Å. A coated tool may include a coating layer located on a surface of the cemented carbide. A cutting tool may include a holder that is extended from a first end toward a second end and may include a pocket on a side of the first end, and the coated tool located in the pocket.

A cBN sinter comprising cubic boron nitride grains and a binder phase, the binder phase comprising Ti.sub.2CN and Co.sub.2B, wherein the ratio I.sub.Ti2CN/I.sub.Co2B of a peak intensity I.sub.Ti2CN assigned to Ti.sub.2CN appearing at 2θ = 41.9° to 42.2° to a peak intensity I.sub.TiAl3 assigned to Co.sub.2B appearing at 2θ = 45.7° to 45.9° is in a range of 0.5 and 2.0 in an XRD measurement.