A cutting tool includes: a substrate; and a coating film disposed on the substrate, wherein the coating film includes an α-Al.sub.2O.sub.3 layer, the α-Al.sub.2O.sub.3 layer includes a plurality of α-Al.sub.2O.sub.3 crystal grains, and has a TC(006) of more than 5 in texture coefficient TC(hkl), and an elastic modulus E1 of the α-Al.sub.2O.sub.3 layer at a room temperature and an elastic modulus E2 of the α-Al.sub.2O.sub.3 layer at 800° C. represent a relation of the following expression B-1:

0<{(E1−E2)/E1}×100<10  Expression B-1.

A cutting tool includes: a substrate; and a coating film disposed on the substrate, wherein the coating film includes an α-Al.sub.2O.sub.3 layer, the α-Al.sub.2O.sub.3 layer includes a plurality of α-Al.sub.2O.sub.3 crystal grains, and has a TC (006) of more than 5 in texture coefficient TC (hkl), and a plastic deformation amount hp of the α-Al.sub.2O.sub.3 layer at 800° C. is 0 nm or more and 100 nm or less.

A cutting tool includes: a substrate; and a coating film disposed on the substrate, wherein the coating film includes an α-Al.sub.2O.sub.3 layer, the α-Al.sub.2O.sub.3 layer includes a plurality of α-Al.sub.2O.sub.3 crystal grains, and has a TC(006) of more than 5 in texture coefficient TC(hkl), and a hardness H1 of the α-Al.sub.2O.sub.3 layer at a room temperature and a hardness H2 of the α-Al.sub.2O.sub.3 layer at 800° C. represent a relation of the following expression A-1:

0<{(H1−H2)/H1}×100<60   Expression A-1.

The coated cutting tool comprises a substrate and a coating layer formed on a surface of the substrate, the coating layer comprises an alternating laminate structure in which two or more first layers and two or more second layers are alternately laminated, the first layer is a compound layer containing Ti(C.sub.aN.sub.1-a), the second layer is a compound layer containing (Ti.sub.xAl.sub.1-x)(C.sub.yN.sub.1-y), an average thickness per layer of each of the first layers and the second layers in the alternating laminate structure is 3 nm or more and 300 nm or less, and an average thickness of the alternating laminate structure is 1.0 μm or more and 8.0 μm or less.

A cutting tool includes a substrate and a coated film arranged on the substrate. The coated film includes a first layer. The first layer includes a plurality of crystal grains. The crystal grains are composed of Al.sub.xTi.sub.1−xC.sub.yN.sub.1−y, wherein x is more than 0.65 and less than 0.95, and y is not less than 0 and less than 0.1. In a first region, the crystal grains have an average aspect ratio of not more than 3.0. In a second region, the crystal grains have an average aspect ratio of more than 3.0 and not more than 10.0. The crystal grains include crystal grains having a cubic crystal structure. The first layer has a ratio of an area occupied by the crystal grains having a cubic crystal structure of not less than 90%. The first layer has a thickness of not less than 2 m and not more than 20 m.

A component obtainable by a process which includes providing a composition and sintering the composition at a sintering temperature of from 1250° C. to 1400° C. for a period of from 3 to 15 minutes. The composition includes hard material particles with an inner core of fused tungsten carbide and an outer shell of tungsten carbide, and a binder metal selected from Co, Ni, Fe and alloys with at least one metal selected from Co, Ni and Fe.

A cutting tool incudes a substrate and a coating that coats a surface of the substrate, the coating including a multilayer structure layer composed of at least one layer A and at least one layer B alternately deposited from a side closer to the substrate toward a side closer to a surface, the layer A having an average composition of Al.sub.xCr.sub.(1-x)N, the layer B being composed of Ti.sub.yAl.sub.zSi.sub.(1-y-z)N, the layer A being composed of a domain region and a matrix region, the domain region having a composition ratio of Cr larger than that of Cr of the matrix region, wherein x has a range of 0.5≤x≤0.8, y has a range of 0.5≤y<0.71, z has a range of 0.29≤z<0.5, and 1−y−z has a range of 0<1−y−z≤0.1.

A base material according to an aspect of the present disclosure is made of a cemented carbide. The cemented carbide includes a first hard phase and a binder phase. The first hard phase consists of WC particles. The binder phase includes at least one element selected from Co and Ni. The base material includes a body portion, and a surface portion provided on a surface of the body portion. The surface portion has a thickness less than or equal to an average particle size in the first hard phase. A ratio (B/A) of an area proportion (B) of the binder phase in a surface of the surface portion to an area proportion (A) of the binder phase in a cross section of the body portion is not less than 1.2 and not more than 2.0.

A cutting insert that suppresses softening of joint material in a joint surface between a sintered body and a base body to improve the joint strength, and that enables size reduction of the sintered body, is provided. The cutting insert includes a sintered body having a cutting edge, and a base body having a leading end where the sintered body is joined via a braze material. The sintered body includes a front surface on a leading side, an upper surface connected to the front surface and forming the cutting edge with the front surface along a connecting edge with the front surface, a bottom surface opposite the upper surface, a back surface opposite the front surface, and two side surfaces. The sintered body and base body are joined together in a joint surface including the bottom surface and back surface of the sintered body. The joint surface in side view has a step-like shape with a leading side thereof being lower than a trailing side thereof.

A coated tool of the present disclosure is provided with a base member and a coating layer located on a surface of the base member. The coating layer includes a TiCNO layer and an Al.sub.2O.sub.3 layer. The Al.sub.2O.sub.3 layer is located in contact with the TiCNO layer at a position farther from the base member than the TiCNO layer is. The TiCNO layer includes a composite protrusion including a first protrusion that projects toward the Al.sub.2O.sub.3 layer, a second protrusion that projects from the first protrusion in a direction intersecting a direction in which the first protrusion projects, and a third protrusion that projects from the second protrusion in a direction intersecting the direction in which the second protrusion projects.