Piston ring for internal combustion engine

摘要

The present invention refers to a piston ring for internal combustion engine, having an outer surface of a coating of Chromium Nitride (CrN and Cr2N) and Niobium Nitride (NbN and Nb4N3), capable of offering greater resistance to peeling of the coating, also maintaining an excellent level of resistance to wear and tear and scratches to the layer of Chromium Nitride deposited.

主权项

1. A piston ring for internal combustion engine comprising a base and at least an outer surface, the base being comprised of a given metallic alloy, the outer surface of the ring comprising a ceramic coating, the ceramic coating being comprised of a deposit of Chromium Nitride and Niobium Nitride, wherein the ceramic coating:
(i) has a porosity rate lower than 10%, has a columnar crystalline structure; (ii) comprises a combination of phases of Chromium Nitride and Niobium Nitride, the Niobium Nitride phase being present in the range of 30 to 40% by weight of the coating; (iii) the outer surface of the coating being composed of Niobium Nitride; and (iv) is a monolayer coating in contact with the base of the ring.