BORON DOPED DIAMOND COATING FILM, AND DIAMOND COATED CUTTING TOOL

摘要

PROBLEM TO BE SOLVED: To improve the oxidation resistance and the lubricity of a diamond coating film.;SOLUTION: Because the boron doped diamond coating film 20 is doped with 0.5 to 1.0 atm.% of boron, a layer of boron oxide (e.g., B₂O₃) is formed on the surface of the diamond coating film 20 when it has been oxidized. Because the progress of the oxidation into the inside of the coating film is suppressed by means of the layer of the boron oxide, the oxidation resistance of the coating film 20 is improved, and also the coefficient of friction of the coating film 20 is reduced and its lubricity is improved. Particularly, the diamond coating film 20 according to the present example is composed of fine crystal grains having a grain size smaller than 1 μm; therefore, the surface of the diamond coating film 20 is smoother than those of usual diamond coating films, and further the layer of boron oxide is formed on the surface of the diamond coating film 20. As a result, the coefficient of friction becomes furthermore small, and the excellent lubricity can be achieved.;COPYRIGHT: (C)2006,JPO&NCIPI