Piston ring

Patent metadata

Field	Value
Publication number	US-2016298764-A1
Application number	US-201415101339-A
Country	US
Kind code	A1
Filing date	Dec 3, 2014
Priority date	Dec 3, 2013
Publication date	Oct 13, 2016
Grant date	—

Abstract

A piston ring for an internal combustion engine may include a metal base and a protective coating disposed on the base to cover at least part of a surface of the base. The coating may be composed of at least one nitride phase formed from at least one metal element and alimunium, and the coating may have an internal stress of less than 1.2 GPa.

First claim

1 . A piston ring for an internal combustion engine comprising: a metal base and a protective coating disposed on the base to cover at least part of a surface of the base, wherein the coating is composed of at least one nitride phase formed from at least one metal element and aluminium (Al), and wherein the coating has an internal stress of less than 1.2 GPa.

2 . The piston ring according to claim 1 , wherein the at least one metal element in the nitride phase is from group B of the periodic table that comprises aluminium (Al), boron (B) and gallium (Ga).

3 . The piston ring according to claim 1 , wherein the coating is a multilayer structure.

4 . The piston ring according to claim 1 , wherein the nitride phase has a composition including at least one of CrN, TiN and NbN.

5 . The piston ring according to claim 1 , wherein the coating has a multilayer structure and the at least one nitride phase is interposed in the multilayer structure, via superimposing a plurality of sublayers, and wherein at least one of the plurality of sublayers is composed of CrN.

6 . The piston ring according to claim 1 , wherein the coating is a physical vapour deposition layer deposited via a high-power impulse magnetron sputtering (HiPIMS) source.

7 . The piston ring according to claim 1 , wherein the protective coating has less than 4×10 4 macroparticles per square millimetre of an average cross-sectional area of the coating.

8 . The piston ring according to claim 1 , wherein the coating includes an element selected from the group of elements in the periodic table of which oxygen (O) and carbon (C) belong, in a quantity of not exceeding ten percent by weight.

9 . The piston ring according to claim 1 , wherein the coating has a hardness between 1500 HV and 2500 HV.

10 . The piston ring according to claim 1 , wherein the coating has a thickness between 10 μm and 100 μm.

11 . The piston ring according to claim 1 , further comprising an intermediate layer, principally composed of chromium, nickel or cobalt, wherein the intermediate layer is disposed between the base and the coating.

12 . The piston ring according to claim 1 , wherein the metal base is a compression ring.

13 . A piston ring for an internal combustion engine comprising: a metal base and a protective coating disposed on the base to cover at least part of an external surface of the base, wherein the coating is multilayer including a nitride phase and a phase of a chromium nitride with a metal element selected from group IIIA of the periodic table, and wherein the coating is substantially free of macroparticles and has an internal stress of less than 1.2 GPa and a periodicity of the multilayers of the coating is less than 10 nm.

14 . The piston ring according to claim 13 , wherein the coating has a multilayer structure.

15 . The piston ring according to claim 13 , wherein the nitride phase is composed of CrN, NbN or TiN.

16 . The piston ring according to claim 13 , wherein the metal element of the phase of the chromium nitride is aluminium (Al).

17 . The piston ring according to claim 13 , wherein the coating is a physical vapour deposition coating disposed via an HiPIMS source.

18 . The piston ring according to claim 13 , wherein the coating has a hardness between 1500 HV and 2500 HV.

19 . The piston ring according to claim 13 , wherein the coating has a thickness between 10 μm and 100 μm and is free of macroparticles.

20 . A piston ring for an internal combustion engine comprising: a metal base and a protective coating disposed on the metal base, wherein the coating is composed of CrAlN and includes between 5×10 2 and 3×10 4 macroparticles per square millimetre of an average cross-sectional area of the coating, and wherein the coating is a physical vapour deposition coating disposed on the base via a cathodic arc source.

21 . The piston ring according to claim 13 , further comprising an intermediate layer principally composed of chromium, nickel or cobalt, disposed between the base and the coating.

Assignees

• Mahle Metal Leve Sa
• Mahle Int Gmbh

Inventors

• Ciminelli Duarte De Souza Mauricio

Classifications

• F16J9/26 Primary

  characterised by the use of particular materials · CPC title