| 摘要 |
Provided is a coated tool including a rigid coating layer which, when used in high-speed intermittent cutting, has excellent chipping resistance and fracture resistance and exhibits excellent wear resistance over a long period. The rigid coating layer comprises a composite nitride or composite carbonitride layer represented by the empirical formula (Ti1-xAlx)(CyN1-y). The rigid coating layer includes crystal grains of the composite nitride or composite carbonitride which have an NaCl-form face-centered cubic structure and in which there are periodic concentration changes, the directions of the periodic concentration changes at least include a direction that makes an angle of 30º or less with a plane parallel to the surface of the tool base. Preferably, the rigid coating layer has a columnar structure, the areal proportion of regions where there are periodic Ti/Al concentration changes is 40% by area or higher, the periods of concentration change are 1-10 nm, the difference between the average of maximal values of the Al content x that periodically changes and the average of minimal values thereof is 0.01-0.1, and at crystal grain boundaries, there are fine crystal grains of a hexagonal structure having an average grain diameter of 0.01-0.3 µm, in an amount of 5% by area or less. |
