Patent ID: 7901796
Filing Date: 2011-03-08
Classification: B23P,C23C,Y10T

Abstract:
1. A coated cutting tool including a base material and a coating layer formed on a surface of said base material, wherein: said coating layer includes an alternate layer, in which each of an A layer and a B layer are stacked alternately, the alternate layer including at least two layers of the A layer and at least two layers of the B layer, said A layer is made of a nitride containing Al and Cr, and when the total number of metal atoms constituting said A layer is represented as 1, a ratio of the number of atoms of said Cr is more than 0 and not more than 0.4, said B layer is made of a nitride containing Ti and Al, and when the total number of metal atoms constituting said B layer is represented as 1, a ratio of the number of atoms of said Al is more than 0 and not more than 0.7, in said alternate layer, total thickness of the A layers is not less than 1 μm and total thickness of the B layers is not less than 0.7 μm, when a thickness of said A layer and a thickness of said B layer in said alternate layer are represented as λa and λb, respectively, a ratio λa/λb in thickness between said A layer and said B layer satisfies 1≦λa/λb<5, and a value of the ratio λa/λb continuously increases as a distance from said base material increases.