| abstract |
the present invention relates to a piece containing a metallic substrate, a non-hydrogenated amorphous carbon coating, of the ta-c or ac type, which coats the substrate, and a chrome (cr), carbon (c) -based sublayer ) and silicon (si) disposed between the metallic substrate and the amorphous carbon coating and on which the amorphous carbon coating is applied, characterized by the fact that the sublayer has, at its interface with the amorphous carbon coating, a ratio between an atomic percentage of silicon and an atomic percentage of chromium (si / cr) between 0.35 and 0.60, and a ratio between an atomic percentage of carbon and the atomic percentage of silicon (c / si) between 2.5 and 3.5. |