Kobe Steel, Ltd.

Kabushiki Kaisha Kobe Seiko Sho

Akitoshi Oota

Koichiro Akari

A diamondlike carbon hard multilayer formed film body comprises a substrate, a diamondlike carbon film mainly composed of diamondlike carbon, and an intermediate layer between the substrate and the diamondlike carbon film. The diamondlike carbon film is composed of, in order from the substrate side, a first diamondlike carbon film and a second diamondlike carbon film. The surface hardness of the first diamondlike carbon film is within the range from not less than 10 GPa to not more than 40 GPa based on nanoindentation test, and the surface hardness of the second diamondlike carbon film is within the range from more than 40 GPa to not more than 90 GPa based on nanoindentation test. According to such a structure, even if a DLC multilayer containing high-hardness DLC film on the outermost surface side is formed in a thickness of not less than about 3 &#x3bc;m on a substrate of a wide range extending from a material with high hardness such as cemented carbide to an iron-based material with low hardness, excellent adhesion to both the substrate and the DLC film can be ensured in addition to excellent wear resistance.

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Takasago, Japan

Akitoshi Oota