Patent ID: 6824823
Filing Date: 2004-11-30
Classification: C23C,Y10T

Abstract:
A method for producing a coated cutting tool which comprises forming a hard coating film by a chemical vapor deposition method on a surface of a hard metal base material of a hard alloy comprising a hard phase of tungsten carbide and at least one material selected from the group consisting of a carbide, a nitride and a carbonitride of at least one metal selected from the group consisting of the Group 4, 5 and 6 of the Periodic Table and a mutual solid solution thereof and a binder phase of at least one element selected from the group consisting of Fe, Ni and Co, wherein the hard coating film comprises a columnar crystal structure layer which comprises at least one material selected from the group consisting of a carbide, a carbonitride and a carbonitroxide of titanium, the columnar crystal structure layer contains particles having crystal particle diameters in a direction horizontal to an interface between the hard coating film and the base material are large and the particles having crystal particle diameters in the same direction are small, a ratio of an average particle diameter of the large particles to an average particle diameter of the small particles is 3 to 50, and a hydrocarbon gas mainly comprising ethane is used as a carbon element-feeding gas for forming the hard coating film.