Cutting tools

A cutting tool comprising a base material and a coating arranged on the base material;

• wherein:
• the coating comprises a titanium compound layer arranged on the base material and an α-Al2O3 layer arranged directly on the titanium compound layer;
• the α-Al2O3 layer is composed of a plurality of aα-Al2O3 particles;
• the α-Al2O3 layer comprises a region A1 and a region A2;
• the region A1 is a region sandwiched between an imaginary plane SA2, which is located at a distance of 0.5 μm from an interface P1 between the titanium compound layer and the α-Al2O3 layer toward the surface side of the coating, and an imaginary plane SA3, which is located at a distance of 1.0 μm from the interface P1 toward the surface side of the coating;
• the region A2 is a region sandwiched between the interface P1 and an imaginary plane SAI that is located at a distance of 0.3 μm from the interface P1 toward the surface side of the coating;
• the titanium compound layer is composed of a plurality of titanium compound particles;
• the titanium compound particles are one selected from the group consisting of TiCN particles, TiCNO particles, TiAlCN particles and TiAlCNO particles:
• the titanium compound layer comprises a region B1 and a region B2;
• the region B1 is a region sandwiched between an imaginary plane SB2, which is located at a distance of 0.5 um from the interface P1 toward the base material side, and an imaginary plane SB3, which is located at a distance of 1.0 μm from the interface P1 toward the base material side;
• the region B2 is a region sandwiched between the interface Pl and an imaginary plane SB1 that is located at a distance of 0.3 um from the interface P1 toward the base material side;
• an average particle diameter al of the α-Al2O3 particles in the region A1, an average particle diameter a2 of the α-Al2O3 particles in the region A2, an average particle diameter b1 of the titanium compound particles in the region B1, and an average particle diameter b2 of the titanium compound particles in the region B2 satisfy relationships represented by respective expressions 1 to 3:
• 0.8
• ≤
• a
• ⁢
• 2
• /
• b
• ⁢
• 2
• ≤
• 1.27
• Expression
• ⁢
• 1
• 1.5
• ≤
• a
• ⁢
• 1
• /
• a
• ⁢
• 2
• ≤
• 10
• Expression
• ⁢
• 2
• 1.45
• ≤
• b
• ⁢
• 1
• /
• b
• ⁢
• 2
• ≤
• 5
• ;
• and
• Expression
• ⁢
• 3
• the average particle diameter b1 is 0.10 μm or more and 0.50 μm or less.