| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a coated cutting insert having excellent cutting performance by forming a fine grainedα-Al2 O3 layer of columnar structure on a TiCx Ny Oz layer of a specific thickness with columnar grains of a specific size. SOLUTION: A WC-Co group substrate is covered with a first innermost layer of TiCx Ny Oz with a layer thickness of 0.1-2μm having isometric grains larger than 0.5μm in size, a second layer of TiCx Ny Oz with a layer thickness of 2-10μm, preferably 4-7μm having columnar grains smaller than about 5μm in diameter, a third layer of TiCx Ny Oz with a layer thickness of 0.1-2μm having isometric grains or acicular grains of 0.5 m or less in size, and an outer layer ofα-Al2 O3 of slip face aggregate structure with a layer thickness of 2-10μm, preferably 3-6μm having surface roughness less than about 0.3μm per about 0.25 mm in measured length.</p> |
