SPECIFICATION OF AN INVENTION PATENT FOR SLIDING ELEMENT FOR USE IN INTERNAL COMBUSTION ENGINES.

摘要

The present invention relates to a sliding element for use in internal combustion engines, provided with a ferrous base (10) covered by a protective surface layer (11 ) comprising at least one nitride applied by physical vapour deposition process (PVD) or a nitrided layer, to which peripheral sliding sur-face a diamond like carbon (DLC) coating (12) is applied, wherein: (i) the coating (12) comprises at least one transition layer (122) comprising WC1-X and a layer (121) of metallic chromium with crystaline structure (BCC - body cubic center) positioned between the ferrous base (10) and an outer amorphous carbon layer (124), and a nanocrystalline phase of carbides, in a multilayer structure of (a-C:H:W) and (a-C:H) in the form of an intermediate layer (123); and (ii) the ratio between the thickness of the outer amorphous carbon layer (124) and the layer (123) composed of a nanocrystalline carbide structure is greater than 4 and/or the thickness ratio of the total layer by the thickness of the outer layer (a-C:H) (124) is greater than 1, preferably between 1 and 1.4.