Hard coating for cutting tool, and cutting tool coated with hard coating

Abstract

A hard coating for a cutting tool being highly resistant to both wear and seizure; and a cutting tool coated with the hard coating. This hard coating is a multilayer film including two or more of the following layered in alternation: first coating layers including AgaCu1-a; and second coating layers including a nitride, oxide, carbide, carbonitride, or boride containing at least one element selected from among group IVA, VA, and VIA elements, aluminum, and silicon. Since the atomic proportion for the first coating layers is between 0.2 and 0.4, inclusive, the layering pitch of the first and second coating layers is between 0.2 and 100 nm, inclusive, and the total thickness is between 0.2 and 10.0 μm, inclusive, the coefficient of friction and cutting resistance can be reduced by the inclusion of silver in the coating, and provide a hard coating that exhibits superb lubricity and resistance to seizure.

Dependencies are inferred from the claim text.