Wear protection layer for piston rings, containing wolfram carbide and chromium carbide

Abstract

Protective layer for piston rings in internal combustion machines, essentially consisting of chromium carbides, tungsten carbide, chromium and nickel, whereby the protective layer against wear and tear is formed of a powder mixture in which the first powder exists as agglomerated and sintered powder made out of at least the alloy components chromium carbide, chromium and nickel, which has not experienced any subsequent embrittling heat treatment such as e.g. a plasma age hardening, whereby the carbides in the powder have a mean diameter that is essentially not greater than 3 μm and a second powder that is also present as an agglomerated and sintered powder and contains tungsten carbide as an essential characteristic and is applied to at least one area of the piston rings by means of thermal spraying, so that two differing layer areas are produced in the protective layer against wear and tear, whereby a first area develops that is primarily rich in chromium carbide and a second area develops that is chiefly rich in tungsten carbide.

Dependencies are inferred from the claim text.