Abstract: A piston ring including at least one intermetallic alloy is provided. A piston ring having a wear-resistant composite composition and a piston ring coating comprising a wear-resistant composition are also provided.

Abstract: The invention relates to a piston ring coated with a coating material by a thermal spray process, exposed to heat treatment of the coating material at an elevated temperature and for a time effective to at least partially diffuse the coating material into the piston ring surface or underlying layer of coating material, and an additionally applied coating material layer subject to successive heat treatments of each coating material layer in order to lay down on the piston ring surface a plurality of layers of the same coating material.

Abstract: A piston ring comprises a coating of a wear-resistant composite composition, particularly intended for high temperature applications. The wear-resistant composite composition comprises a ceramic compound and at least 50 volume %, based on the total volume of the wear-resistant composition, of an intermetallic nickel-aluminide chosen from the group consisting of NiAl and Ni3Al. A piston ring comprises a wear-resistant composite composition, particularly intended for high temperature applications. The wear-resistant composite composition comprises a ceramic compound and at least an intermetallic nickel-aluminide chosen from the group consisting of NiAl and Ni3Al.

Abstract: The present invention relates to a process for electrolytic coating of a substratum, especially a piston ring, with a ceramic chrome layer, the substratum being arranged at an electrode connected to voltage and chromium ions for coating the substratum being present in the electrolyte. Furthermore the electrolyte contains a crystalline carrier structure which is present in the form of ions in the electrolyte, said carrier structure acting as a carrier of the chromium ions which are present in the electrolyte, and being incorporated in the ceramic chrome layer forming on the substratum by the process. The invention also relates to a ceramic chrome layer which is applied to a substratum, especially a piston ring, and is characterised in that the chrome layer is formed by a process as stated above and comprises a crystalline carrier structure.