Surface-coated cutting tool having hard coating layer that exhibits excellent chipping resistance

A surface-coated cutting tool comprising:

• a tool body made of cemented carbide using tungsten carbide, titanium carbonitride cermet, or cubic boron nitride ultra-high pressure sintered material;
• and
• a hard coating layer provided on a surface of the tool body, wherein
• (a) the hard coating layer comprises at least a Ti and Al complex nitride or complex carbonitride layer, which is deposited by a chemical vapor deposition method and has an average layer thickness of 2 μm to 20 μm;
• and an average content ratio xavg, which is an average content ratio of Al with respect to a total amount of Ti and Al in the Ti and Al complex nitride or complex carbonitride layer in atomic ratio, and an average content ratio yavg, which is an average content ratio of C with respect to a total amount of C and N in the Ti and Al complex nitride or complex carbonitride layer in atomic ratio, satisfy 0.60≤xavg≤0.95;
• and 0≤yavg≤0.005, respectively, in a case where a composition formula of the Ti and Al complex nitride or complex carbonitride layer is expressed by (Ti1-xAlx)(CyN1-y),
• (b) the complex nitride or complex carbonitride layer comprises at least a phase of Ti and Al complex nitride or complex carbonitride having a NaCl face-centered cubic structure,
• (c) an area ratio of crystal grains having an average crystal grain misorientation of 2° or more relative to the Ti and Al complex nitride or complex carbonitride layer is 20% or more, when crystal orientations of crystal grains having the NaCl face-centered cubic structure in crystal grains constituting the complex nitride or carbonitride layer are analyzed along a vertical cross-sectional direction with an electron beam backward scattering diffraction device and the average crystal grain misorientation of the individual crystal grains is obtained, and
• (d) when inclined angles of normal lines of {100} plane as crystal plane of the crystal grains relative to a normal line of a surface of the cutting tool body are measured by equally dividing the complex nitride or complex carbonitride layer into two regions of an interface side region and a surface side region in a layer thickness direction;
• and frequencies in each of sections, in which measured inclined angles within a range of 0° to 45° relative to the normal line of the surface of the cutting tool among the measured inclined angles are divided in every 0.25° pitch, are tallied,
• Mdeg, which is the ratio of a sum of frequencies in a range of 0° to 12° in the interface side region to an overall frequency in an inclined angle distribution, is 10% to 40%, and
• a highest peak is present in an inclined angles sections in a range of 0° to 12°, and in the surface side region and Ndeg, which is the ratio of a sum of frequencies in a range of 0° to 12° in the surface side region to an overall frequency in an inclined angle distribution, is Mdeg+10% to Mdeg+3 0%.