Sliding element for use in internal combustion engine

Patent metadata

Field	Value
Publication number	US-9759322-B2
Application number	US-201314379286-A
Country	US
Kind code	B2
Filing date	Feb 15, 2013
Priority date	Feb 16, 2012
Publication date	Sep 12, 2017
Grant date	Sep 12, 2017

Abstract

A sliding element for use in an internal combustion engine may include a ferrous base having a peripheral sliding surface covered by a protective surface layer, the protective surface layer including at least one nitride applied via at least one of physical vapour deposition and a nitrided layer. The peripheral sliding surface may have a diamond like carbon (DLC) coating disposed thereon. The coating may include at least one of (a) one or more transition layers composed of WC1-x and (b) an adhesive layer of metallic chromium with a crystal structure. The coating may include an intermediate layer of metal DLC, the metal may be tungsten in a multilayer structure of a-C:H:W and a-C:H, and an outer layer of metal-free DLC.

First claim

The invention claimed is:

1. A sliding element for use in an internal combustion engine, comprising:
a ferrous base having a peripheral sliding surface covered by a protective surface layer including at least one nitride applied via at least one of physical vapour deposition and a nitrided layer, the peripheral sliding surface having a diamond like carbon (DLC) coating disposed thereon,
wherein:
(i) the coating includes at least one of (a) one or more transition layers composed of WC1-x and (b) an adhesive layer of metallic chromium with a crystal structure, an intermediate layer of metal DLC, wherein the metal is tungsten in a multilayer structure of a-C:H:W and a-C:H, and an outer layer of metal-free DLC;
(ii) a ratio between a thickness of the outer layer and the intermediate layer is between 4 and 5; and
(iii) a thickness ratio of the total layers of the coating by a thickness of the outer layer is between 1 and 1.4.

2. The sliding element according to claim 1 , wherein the outer layer includes hydrogen.

3. The sliding element according to claim 1 , wherein the transition layer includes precipitated nanocrystalline tungsten carbide.

4. The sliding element according to claim 3 , wherein at least one of the coating layers is completely amorphous.

5. The sliding element according to claim 3 , wherein the transition layer has a thickness between 100 nm and 500 nm.

6. The sliding element according to claim 1 , wherein at least one of the coating layers is completely amorphous.

7. The sliding element according to claim 1 , wherein the transition layer has a thickness between 100 nm and 500 nm.

8. The sliding element according to claim 1 , wherein the coating has a total thickness of 4 μm to 15 μm.

9. The sliding element according to claim 1 , wherein the coating includes a hardness of 1,800 HV to 3,000 HV.

10. The sliding element according to claim 1 , wherein the outer layer includes a structure of a-C:H.

11. The sliding element according to claim 1 , wherein the coating has a total thickness of 8 μm to 12 μm.

12. A sliding element for an internal combustion engine, comprising:
a ferrous base having a peripheral sliding surface of a diamond like carbon (DLC) coating disposed thereon,
wherein:
(i) the coating includes, from an outer portion towards the ferrous base, an amorphous outer layer having a structure of a-C:H, an intermediate layer including a nanocrystalline structure of carbides in a multilayer structure of a-C:H:W and a-C:H, a transition layer constituting WC1-x, a layer of metallic chromium with a crystal structure, and a protective layer composed of at least one nitride applied via physical vapor deposition;
(ii) a ratio between a thickness of the amorphous outer layer and the intermediate layer is between 4 and 5;
(iii) a thickness ratio of the total layers by a thickness of the outer layer is between 1 and 1.4; and
(iv) the coating has an integrated intensity ratio in the Raman spectrum between D band to G band within a range of of 0.2 and 1.0.

13. The sliding element according to claim 12 , wherein the transition layer includes precipitated nano crystalline tungsten carbide.

14. The sliding element according to claim 12 , wherein at least one of the coating layers is completely amorphous.

15. The sliding element according to claim 12 , wherein the transition layer has a thickness between 100 nm and 500 nm.

16. The sliding element according to claim 15 , wherein the transition layer includes precipitated nano crystalline tungsten carbide.

17. The sliding element according to claim 16 , wherein at least one of the coating layers is completely amorphous.

18. The sliding element according to claim 12 , wherein the sliding element is a piston ring.

19. The sliding element according to claim 12 , wherein the transition layer is deposited via a sputtering process.

20. A sliding element for an internal combustion engine, comprising:
a ferrous base having a peripheral sliding surface including a diamond like carbon coating disposed thereon, the coating including:
a protective layer disposed on the base composed of at least one nitride; a layer of metallic chromium with a crystal structure disposed on the protective layer;
a transition layer composed of WC1-x disposed on the layer of metallic chromium, the transition layer including a thickness between 100 nm and 500 nm;
an intermediate layer including a nanocrystalline structure of carbides in a multilayer structure of a-C:H:W and a-C:H disposed between the transition layer and an outer layer, the outer layer composed of amorphous carbine having a structure of a-C:H;

wherein:
(i) a ratio between a thickness of the amorphous outer layer and the intermediate layer is between 4 and 5,
(ii) a thickness ratio of the total layers of the coating by a thickness of the outer layer is between 1 and 1.4,
(iii) the coating has a thickness between 8 μm and 12 μm and a hardness of 1,800 HV to 3,000 HV; and
(iv) the coating has an integrated intensity ratio in the Raman spectrum between D band to G band within a range of 0.2 and 1.0.

Assignees

• Mahle Metal Leve Sa
• Mahle Int Gmbh

Inventors

• Araujo Juliano A
• Costa Nuno

Classifications

• C23C28/04

  only coatings of inorganic non-metallic material · CPC title

• C10N2080/00

  Special pretreatment of the material to be lubricated, e.g. phosphatising or chromatising of a metal · CPC title

• C23C14/0635

  Carbides · CPC title

• F16C33/124

  Details of overlays · CPC title

• C23C28/046

  with at least one amorphous inorganic material layer, e.g. DLC, a-C:H, a-C:Me, the layer being doped or not · CPC title