SURFACE-COATED CUTTING TOOL

摘要

PROBLEM TO BE SOLVED: To provide a coated tool which demonstrates excellent chipping resistance and wear resistance even when a difficult-to-machine material is cut at a high speed cutting condition involving high heat generation.SOLUTION: A hard coating layer formed on a surface of a tool base comprises: (a) a lower layer having an average layer thickness of 0.5-5.0 μm, satisfying a composition formula of (AlTi)N(0.25≤x≤0.55), and having a Young's modulus E satisfying 400 GPa≤E≤550 GPa; (b) an intermediate layer having an average layer thickness of 0.5-5.0 μm, satisfying a composition formula of (AlCr)N(0.25≤y≤0.50), having a Young's modulus E satisfying 150 GPa≤E≤300 GPa; and (c) an upper layer consisting of a Cr-Nitride layer having an average layer thickness of 0.5-5.0 μm.