The present disclosure provides a multilayer coated cutting material having increased wear resistance at high temperatures, a method for manufacturing the same, and a cutting tool insert for mechanical machining including the same. According to an embodiment of the present disclosure, the multilayer coated cutting material includes a cemented carbide, cermet, ceramic, a cubic crystal boron nitride-based material or a hard alloy body of high-speed steel, and a cutting layer positioned on the base material and configured in multiple layers.

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.

A cutting tool comprises a substrate and a coating that coats the substrate, the coating including an α-alumina layer provided on the substrate, the α-alumina layer including crystal grains of α-alumina, the α-alumina layer including a lower portion and an upper portion, the upper portion being occupied in area at a ratio of 50% or more by crystal grains of α-alumina having a (006) plane with a normal thereto having a direction within ±15° with respect to a direction of the normal to the second interface, the lower portion being occupied in area at a ratio of 50% or more by crystal grains of α-alumina having a (110) plane with a normal thereto having a direction within ±15° with respect to the direction of the normal to the second interface, the α-alumina layer having a thickness of 3 μm or more and 20 μm or less.

A surface-coated cutting tool has a hard coating layer and a tool body, which is coated with a lower layer including a TiCN layer having at least an NaCl type face-centered cubic crystal structure and an upper layer formed of a TiAlCN layer having a single phase crystal structure of NaCl type face-centered cubic crystals or a mixed phase crystal structure of NaCl type face-centered cubic crystals and hexagonal crystals. The tool body is further coated with an outermost surface layer including an Al.sub.2O.sub.3 layer, when the layer of a complex nitride or complex carbonitride of Ti and Al is expressed by the composition formula: (Ti.sub.1-xAl.sub.x)(C.sub.yN.sub.1-y), the average amount Xave of Al in Ti and Al and the average amount Yave of C in C and N (both Xave and Yave are atomic ratios) respectively satisfy 0.60≦Xave≦0.95 and 0≦Yave≦0.005.

A surface-coated cutting tool includes a base material and a coating formed on the base material. The coating includes an α-Al.sub.2O.sub.3 layer. The α-Al.sub.2O.sub.3 layer contains a plurality of α-Al.sub.2O.sub.3 crystal grains and a plurality of κ-Al.sub.2O.sub.3 crystal grains, and has a TC(006) of more than 5 in a texture coefficient TC(hkl). A ratio of C.sub.κ to a sum of C.sub.α and C.sub.κ: [C.sub.κ/(C.sub.α+C.sub.κ)×100](%) is 0.05 to 7%, where C.sub.α is a total number of peak counts of the α-Al.sub.2O.sub.3 crystal grains obtained from measurement data of x-ray diffraction for the coating, and C.sub.κ is a total number of peak counts of the κ-Al.sub.2O.sub.3 crystal grains obtained from the measurement data of the x-ray diffraction for the coating.

A surface coated cutting tool comprises a base material and a coating layer that coats the base material, the coating layer including an alternate layer composed of a first unit layer and a second unit layer alternately stacked, the first unit layer being composed of a nitride containing aluminum and zirconium, in the first unit layer, when the total number of metal atoms constituting the first unit layer is represented as 1, a ratio thereto of the number of atoms of the zirconium being not less than 0.65 and not more than 0.95, the second unit layer being composed of a nitride containing titanium and silicon, in the second unit layer, when the total number of metal atoms constituting the second unit layer is represented as 1, a ratio thereto of the number of atoms of the silicon being larger than 0 and not more than 0.20.

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.

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.

The present invention relates to a coated cutting tool including a Cr-containing cemented carbide substrate having WC, a binder phase and a gamma phase. The cemented carbide includes a gradient surface zone with a thickness of between 2 to 100 μm, which is binder phase enriched and depleted of gamma phase. The cemented carbide includes M.sub.7C.sub.3 carbides in an amount of between 0.5 to 7 area % measured in the bulk, where M is elements being Cr, W and at least one binder metal. The coated cutting inserts shows an improved edge line toughness.

A coated cutting tool of a cemented carbide substrate made of WC, a metallic binder phase and a gamma phase has a well distributed gamma phase and a reduced amount of abnormal WC grains. Further, the coated cutting tool is provided with a CVD coating of TiCN and an α-Al.sub.2O.sub.3 layer, wherein the α-Al.sub.2O.sub.3 layer exhibits a texture coefficient TC(0 0 12)≥7.2 and wherein in the ratio I(0 0 12)/I(0 1 14)≥1. The coated cutting tool has an increased resistance against plastic deformation. whilst maintaining toughness.