| 摘要 |
PROBLEM TO BE SOLVED: To eliminate an applying process of a die releasing agent for stable long usage by providing a top surface layer comprising a smooth ceramic film composed of a given thickness of Cr and N as main components on the first and second ceramic films. SOLUTION: A ceramic film with thickness of 0.1μm or more is used as a top surface layer, so that oxidization of the ceramic films of the lower layers can be prevented for eliminating chemical degrading or exfoliation. Furthermore, the first smooth ceramic film composed of Cr and N as main components and the ceramic film of high hardness are alternately laminated, so that chemical stability and sliding characteristic are further improved, resulting in the significant improvement of baking resistance. Therefore, it is preferable that total thickness of the overall ceramic film including the top surface layer is 0.5-50μm. It is preferable that the first ceramic film is composed of, at atom%, 50-70% Cr and 25-50% N, and that the top surface layer ceramic film is composed of 50-60% Cr and 40-50% N.
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