Provided is a cutting tool including a base material and a coating layer provided on the base material, the coating layer including a titanium carbonitride layer provided on the base material, an intermediate layer provided on the titanium carbonitride layer in contact therewith, and an alumina layer provided on the intermediate layer in contact therewith, the intermediate layer being composed of a compound made of titanium, carbon, oxygen, and nitrogen, the intermediate layer having a thickness of more than 1 μm, when P.sub.C1 atomic % represents an atomic ratio of the carbon in an interface between the intermediate layer and the alumina layer, and P.sub.C2 atomic % represents an atomic ratio of the carbon at a point A away from the interface by 1 μm on a side of the intermediate layer, a ratio P.sub.C1/P.sub.C2 of the P.sub.C1 to the P.sub.C2 being more than or equal to 1.03.

A coated cutting tool for chip forming machining of metals includes a substrate having a surface coated with a chemical vapour deposition (CVD) coating. The substrate is coated with a coating having a layer of α-Al.sub.2O.sub.3, wherein the α-Al.sub.2O.sub.3 layer exhibits a texture coefficient TC(0 0 12)≥7.2 and wherein the ratio of I(0 0 12)/I(0 1 14)≥0.8. The coating further includes a MTCVD TiCN layer located between the substrate and the α-Al.sub.2O.sub.3 layer. The MTCVD TiCN layer exhibits a pole figure, as measured by EBSD, in a portion of the MTCVD TiCN layer parallel to the outer surface of the coating and less than 1 μm from the outer surface of the MTCVD TiCN, wherein a pole plot based on the data of the pole figure, with a bin size of 0.25° over a tilt angle range of 0°≤β≤45° from the normal of the outer surface of the coating shows a ratio of intensity within β≤15° tilt angle to the intensity within 0°≤β≤45° of ≥45%.

A cutting tool including a rake face and a flank face includes: a substrate; and a coating film disposed on the substrate, wherein the coating film includes an Al.sub.2O.sub.3 layer, residual stress of the Al.sub.2O.sub.3 layer has a minimum value R.sub.min at at least a portion of a region d1 of the rake face, the minimum value R.sub.min is more than −0.27 GPa and less than or equal to −0.1 GPa.

A cutting tool including a rake face and a flank face includes: a substrate; and a coating film disposed on the substrate, wherein the coating film includes an Al.sub.2O.sub.3 layer, residual stress of the Al.sub.2O.sub.3 layer has a minimum value R.sub.min at at least a portion of a region f1 in the flank face, the minimum value R.sub.min is more than or equal to −0.25 GPa and less than or equal to −0.1 GPa.

A coated tool of the present disclosure may include a base and a coating layer covering at least a part of the base. The base may include a hard phase of a carbonitride including Ti and a binder phase including at least one of Co and Ni and has a thermal expansion coefficient at 25 to 1000° C. of 9.0×10.sup.−6/° C. or more. The coating layer may include a TiCN layer and an Al.sub.2O.sub.3 layer positioned on the TiCN layer. The TiCN layer may have a compressive stress of 250 to 500 MPa. The Al.sub.2O.sub.3 layer may have a thickness of 2 μm or more and a compressive stress of 450 MPa or more, and the value of the compressive stress is greater than the compressive stress of the TiCN layer.

A coated cutting tool comprising a substrate comprising a cubic boron nitride sintered body and a coating layer formed on the substrate, wherein the coating layer comprises a Ti carbonitride layer comprising Ti(C.sub.xN.sub.1-x); an average thickness of the Ti carbonitride layer is 0.5 μm or more and 5.0 μm or less; in the Ti carbonitride layer, R75 is higher than R25; in the Ti carbonitride layer, a texture coefficient TC (111) of a (111) plane is 1.0 or more and 2.0 or less; and in X-ray diffraction measurement of the Ti carbonitride layer, an absolute value of a difference between a maximum value and a minimum value of 2θ is 0.1° or less on the (111) plane when the measurement is performed at each of ψ angles of 0°, 30°, 50° and 70°.

A coated tool in the present disclosure includes a base and a coating layer located on a surface of the base. The coating layer includes an intermediate layer including Ti, and an Al.sub.2O.sub.3 layer. The Al.sub.2O.sub.3 layer is located in contact with the intermediate layer at a position further away from the base than the intermediate layer. The intermediate layer includes a plurality of first protrusions protruding toward the Al.sub.2O.sub.3 layer. An average distance between the plurality of first protrusions is 70-120 nm. A cutting tool in the present disclosure includes a holder which is extended from a first end toward a second end and includes a pocket on a side of the first end, and the coated tool located in the pocket.

A coated tool in the present disclosure includes a base and a coating layer located on a surface of the base. The coating layer includes a TiCN layer, an intermediate layer including Ti, and an Al.sub.2O.sub.3 layer in this order from a side of the base. The Al.sub.2O.sub.3 layer is located in contact with the intermediate layer at a position further away from the base than the intermediate layer. The intermediate layer includes a plurality of first protrusions protruding toward the Al.sub.2O.sub.3 layer. An average area of the plurality of first protrusions is 1700 nm.sup.2 or less. A cutting tool in the present disclosure includes a holder which is extended from a first end toward a second end and includes a pocket on a side of the first end, and the coated tool located in the pocket.

The present invention relates to a cutting tool, which performs, like a drill or a ball end mill, cutting while rotating in a state in which the center of the tip end is in contact with a work material, and includes a wear-resistant layer formed at the tip end thereof, wherein a portion of the wear-resistant layer is selectively removed through tip end polishing from the center of the tip end of the drill or the ball end mill to a predetermined area, so as to restrain micro-brittle wear generated in an ultra-low speed region, and thus remarkably improving the cutting lifespan of the cutting tool such as the drill or the ball end mill.

The present invention relates to a cutting tool, which performs, like a drill or a ball end mill, cutting while rotating in a state in which the center of the tip end is in contact with a work material, and includes a wear-resistant layer formed at the tip end thereof, wherein a portion of the wear-resistant layer is selectively removed through tip end polishing from the center of the tip end of the drill or the ball end mill to a predetermined area, so as to restrain micro-brittle wear generated in an ultra-low speed region, and thus remarkably improving the cutting lifespan of the cutting tool such as the drill or the ball end mill.