Coating for a piston ring
AssigneeMahle International GmbH
InventorsFabio Mendes de Araujo, Luiz Felipe Viegas Rosa Rezende, Nikhil Nachappa Tychodianda Kushalappa, Samuel Jose Muniz De Toledo
Life of this patent
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Abstract
A piston ring and method of forming includes a base portion formed of a metallic material, an outer contact surface and an inner contact surface extending between a first face and a second face that is opposite the first face of the piston ring, a chromium coating layer on the second face, the outer contact surface, and the inner contact surface, a layer of diamond-like carbon (DLC) disposed over the chromium coating layer on the outer contact surface, and a phosphate layer on a first face.
Claims20
A piston ring, comprising:
- a base portion formed of a metallic material;
- an outer contact surface and an inner contact surface extending between a first face and a second face that is opposite the first face of the piston ring;
- a chromium coating layer on the inner contact surface, the outer contact surface, and the second face;
- a layer of diamond-like carbon (DLC) disposed over the chromium coating layer on the outer contact surface;
- a phosphate layer provided on the first face;
- and
- wherein the phosphate layer is disposed directly on the metallic material of the base portion of the first face between an upper outer corner region and an upper inner corner region of the base portion.
A piston ring, comprising:
- a base portion formed of a metallic material, the base portion including an outer contact surface and an inner contact surface extending between a first face and a second face that is opposite the first face;
- a chromium coating layer on the inner contact surface, the outer contact surface, and the second face;
- a layer of diamond-like carbon (DLC) disposed over the chromium coating layer on the outer contact surface;
- a phosphate layer provided on the first face;
- wherein the layer of DLC has a diminishing thickness at a lower outer corner region of the base portion and an upper outer corner region of the base portion;
- and
- wherein the phosphate layer partially overlaps the DLC at the upper outer corner region and partially overlaps the chromium coating layer at an upper inner corner region of the base portion.
Dependencies are inferred from the claim text.