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.

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 laminated hard film is obtained by laminating a layer A and a layer B. The layer A has a composition different from that of the layer B. The layer A is formed of (Ti.sub.aCr.sub.bAl.sub.cSi.sub.d)(C.sub.xN.sub.1-x) and satisifies the relationship of 0≦a≦0.10, 0.10≦b≦0.50, 0.50≦c≦0.90, 0≦d≦0.05, a+b+c+d=1 and 0≦x≦0.5. The layer B is formed of (Cr.sub.eSi.sub.1-e)(C.sub.yN.sub.1-y) and satisfies the relationship of 0.90≦e≦1.0 and 0≦y≦0.5, or is formed of (Al.sub.fSi.sub.1-f)(C.sub.2N.sub.1-z) and satisfies the relationship of 0.90≦f≦1.0 and 0≦x≦0.5. Each of the layer A and the layer B has a thickness of 2 to 100 nm, and the layer A and the layer B are each alternately laminated.

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.

The invention relates to a method for producing a coated cutting tool in which a coating with at least one oxide layer is applied to a base layer by means of a PVD method. The method includes voltage-pulsed sputtering of at least one cathode metal selected from the group of aluminum, scandium, yttrium, silicon, zinc, titanium, zirconium, hafnium, chromium, niobium, and tantalum, as well as mixtures and alloys thereof in the presence of a reactive gas; and the depositing of at least one oxide layer formed by converting the reactive gas with the sputtered cathode metal onto the base body. The cathode metal includes at least aluminum. Dinitrogen oxide is used as the reactive gas. The at least one oxide layer is in the form of an oxide, mixed oxide, or oxide mixture of the at least one cathode metal.

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.

A cutting tool comprises a substrate and a coating layer provided on the substrate, the coating layer including a multilayer structure layer composed of a first unit layer and a second unit layer, and a lone layer, the lone layer including cubic Ti.sub.zAl.sub.1-zN crystal grains, an atomic ratio z of Ti in the Ti.sub.zAl.sub.1-zN being 0.4 or more and less than 0.55, the lone layer having a thickness with an average value of 2.5 nm or more and 10 nm or less, the multilayer structure layer having a thickness with an average value of 10 nm or more and 45 nm or less, one multilayer structure layer and one lone layer forming a repetitive unit having a thickness with an average value of 20 nm to 50 nm, a maximum value of 40 nm to 60 nm, and a minimum value of 10 nm to 30 nm.

A surface-coated cutting tool includes a lower layer including a Ti compound layer, an intermediate layer including an α-Al.sub.2O.sub.3 layer, and an upper layer including a Zr-containing α-Al.sub.2O.sub.3 layer. The outermost layer of the lower layer contains 0.5 to 3 at % of oxygen. The frequencies of inclination angles between a normal line to a (0001) plane of Al.sub.2O.sub.3 grains of the intermediate layer and a normal line to a surface of a tool body have a highest peak in an inclination angle division of 0 to 10°. The ratio of the frequencies is 50 to 70%. The frequencies between the normal line to the (0001) plane of Al.sub.2O.sub.3 grains of the entirety of the intermediate and the upper layers and the normal line to the tool body surface have a highest peak in an inclination angle division of 0 to 10°. The ratio of the frequencies is 75% or more.