The present disclosure relates to a cutting tool of a cemented carbide substrate including WC and a binder phase having one or more of Co, Fe and Ni, wherein the cemented carbide also includes a finely dispersed eta phase of Me12C and/or Me6C carbides, where Me is one or more metals selected from W, Mo and the binder phase metals, wherein the substoichiometric carbon content in the cemented carbide is between −0.30 to −0.16 wt %. The disclosed cutting tool will achieve an improved resistance against comb cracks.

An end-mill comprising a shank and a cutting portion along its longitudinal axis, and formed by combining ceramic and metal based materials via a brazing method. The cutting portion includes a cutting diameter varying between 2 to 20 mm, at least one web thickness found at a blade part, at least one helix angle having a cutting edge thereon, a core diameter that is at least 0.7 times the cutting diameter, at least one corner radius found at the tip part of the blades between the flutes, and axial and radial rake angles at which a cutting operation is made. TiAlN coating is applied over the ceramic-metal based end-mill by a PVD method in order to extend the service life of the end-mill, increase abrasion resistance, and minimize the welding (sticking) problem of chips on the cutting tools.

A cutting tool according to one aspect of the present disclosure includes an attaching portion, a cutting portion having a core portion and a surface portion, and a joint portion. The attaching portion includes a hard component and a hard material. The hard component is at least one selected from the group consisting of TiC, TiCN, W, WC, Al.sub.2O.sub.3, and a combination of at least one of CBN and diamond and at least one of W and WC. The hard material includes one or two or more types of iron group elements, and has a Young's modulus of not more than 350 GPa. The core portion includes a cemented carbide material. The surface portion includes PCD or CBN. The cutting portion has a chamfer portion. The surface portion includes a groove, a flank face, and a cutting edge. The cutting edge extends toward the attaching portion.

The present disclosure relates to a cutting tool of a cemented carbide substrate including WC and a binder phase having one or more of Co, Fe and Ni, wherein the cemented carbide also includes a finely dispersed eta phase of Me12C and/or Me6C carbides, where Me is one or more metals selected from W, Mo and the binder phase metals, wherein the substoichiometric carbon content in the cemented carbide is between 0.30 to 0.16 wt %. The disclosed cutting tool will achieve an improved resistance against comb cracks.

A cutting tool according to one aspect of the present disclosure includes an attaching portion, a cutting portion having a core portion and a surface portion, and a joint portion. The attaching portion includes a hard component and a hard material. The hard component is at least one selected from the group consisting of TiC, TiCN, W, WC, Al.sub.2O.sub.3, and a combination of at least one of CBN and diamond and at least one of W and WC. The hard material includes one or two or more types of iron group elements, and has a Young's modulus of not more than 350 GPa. The core portion includes a cemented carbide material. The surface portion includes PCD or CBN. The cutting portion has a chamfer portion. The surface portion includes a groove, a flank face, and a cutting edge. The cutting edge extends toward the attaching portion.

A surface-coated cutting tool includes a base material and a coating formed on the base material. The coating includes an -Al.sub.2O.sub.3 layer. The -Al.sub.2O.sub.3 layer contains -Al.sub.2O.sub.3 crystal grains and sulfur, and has a TC(006) of more than 5 in texture coefficient TC(hkl). The sulfur has a concentration distribution in which a concentration of the sulfur decreases in a direction away from a base-material-side surface of the -Al.sub.2O.sub.3 layer, in a thickness direction of the -Al.sub.2O.sub.3 layer.

The present invention is an end-mill (A) comprising a shank (B) and a cutting portion (C) along its longitudinal axis (4), and formed by combining ceramic and metal based materials via brazing method, comprising: a cutting diameter (1) varying between 2 to 20 mm, at least one web thickness (18) 0 found at a blade (26) part, at least one helix angle (10) having a cutting edge (13) thereon, a core diameter (16) that is at least 0.7 times the cutting diameter (1), at least one corner radius (5) found at the tip part of the blades (26) between the flutes (9) and axial and radial rake angles (17) at which cutting operation is made. TiAlN coating is applied over ceramic-metal based 5 end-mill (A) by PVD method in order to extend the service life of the end-mill, increase abrasion resistance, and minimize the welding (sticking) problem of chips on the cutting tools.

A surface-coated cutting tool includes a base material and a coating formed on the base material. The coating includes an -Al.sub.2O.sub.3 layer. The -Al.sub.2O.sub.3 layer contains -Al.sub.2O.sub.3 crystal grains and sulfur, and has a TC(006) of more than 5 in texture coefficient TC(hkl). The sulfur has a concentration distribution in which a concentration of the sulfur decreases in a direction away from a base-material-side surface of the -Al.sub.2O.sub.3 layer, in a thickness direction of the -Al.sub.2O.sub.3 layer.