COMPOUND SINTERED COMPACT CUTTING TOOL AND COMPOUND SINTERED COMPACT CUTTING TOOL WITH COATED SURFACE

摘要

A composite sintered body cutting tool; and a surface coated composite body cutting tool, in which a hard coating layer is deposited at least on the rake face, are provided. The composite sintered body cutting tool is made of a composite sintered body of: a TiCN-based cermet layer (2); and a WC-based cemented carbide layer (3). The angle between the rake face (4) and the flank face (5) of the cutting tool is 90°. The rake face (4) including a cutting edge of the cutting tool is constituted from the WC-based cemented carbide layer (3), in which 4 to 17 mass% of an iron group metal component and 75 mass% or more of W are included; and a major hard phase component is WC. The thickness of the WC-based cemented carbide layer (3) is 0.05 to 0.3 times of a thickness of the composite sintered body. The TiCN-based cermet layer (2) is constituted from a single layer of a TiCN-based cermet layer (2), including at least, 4 to 25 mass% of an iron group metal component, less than 15 mass% of W, 2 to 15 mass% of Mo, 2 to 10 mass% of Nb and 0.2 to 2 mass% of Cr in a case where contents of constituting components of the cermet layer are expressed as contents of metal components, and satisfies the Co content relative to the total content of Co and Ni of 0.5 to 0.8 with respect to Co and Ni of the iron group metal component in a mass ratio. When the height profile from the upper end to the lower end of the flank face (5) is measured in the plane, which passes the center of the rake face (4) of the cutting tool and is perpendicular to both of the rake face (4) and the flank face (5), as the line, which passes the ridge line where the rake face (4) and the flank face (5) intersect and perpendicular to the rake face (4), being the reference line, the maximum elevation difference value (10) of the height profile is in a ratio of 0.01 or less with respect to the thickness of the composite sintered body from the front surface of the rake face (4) to a rear surface.