To provide a surface coated cemented carbide-made tool having hard coating layer exhibiting excellent chipping resistance in high-speed cutting material hard to cut.
In surface coated cemented carbide-made tool, electron beams are applied to individual crystal grains having a hexagonal system crystal lattice existing in a measurement range of a surface polishing surface using a field emission type scanning electron microscope to measure an angle of inclination made by a normal of a (0001) face, which is a crystal plane of the crystal grain, to the normal of the surface polishing surface. An inclination angle frequency distribution graph is created from the measurement results. The upper layer of the hard coating layer is formed by a modified α type Al2O3 layer, which has the peak in a section of inclination angle ranging from 7 to 15 degrees and a section of inclination angle ranging from 0 to 7 degrees in the inclination angle frequency distribution graph and shows an inclination angle frequency distribution graph in which the total frequency present in the range from 7 to 15 degrees occupies the ratio of 35 to 50% or more of the entire frequency. and the total frequency present in the range from 0 to 7 degrees occupies the ratio of 25 to 40% or more of the entire frequency. The surface roughness Ra of the modified α type Al2O3 is set at 0.2μm or less.
HARA HIROSHI
KONO KAZUHIRO
Kutaro Kamoi
Kageyama Shuichi