Coated cemented carbide cutting tool

摘要: Intended is to provide a coated cutting tool having significantly improved life, as compared that of conventional tool, by greatly improving the resistance flaking coating film layer during and also itself wear cratering, thereby improve fracture film. For achieving above-mentioned purpose, use made cemented carbide comprising and, thereon, structure wherein an outer aluminum oxide consisting substantially α type crystal has, in first row grains growing just above inner layer, region which both λ are present mixed, contain no pores.