Carbon containing layer

• US RE34,035 E
• Filed: 09/14/1990
• Issued: 08/18/1992
• Est. Priority Date: 02/27/1982
• Status: Expired due to Term

• Current Assignee: Fraunhofer Gesellschaft Zur Foerderung Der Angewandten Forsching E.V.
• Original Assignee: US Philips Corporation (Koninklijke Philips N.V.)
• Inventors: Dimigen, Heinz, Hubsch, Hubertus
• Primary Examiner(s): HERBERT JR, THOMAS
• Application Number:
  US07/584,412
• Time in Patent Office: 704 Days
• Field of Search: 428/698, 428/469, 428/244, 428/457, 204/192.16, 427/249, 427/250
• US Class Current: 428/408
• CPC Class Codes: C23C 14/06 characterised by the coating material C23C14/0021 , C23C14/04 take precedence
• CPC Class Codes: F16C 33/16 Sliding surface consisting mainly of graphite
• CPC Class Codes: Y10T 428/30 Self-sustaining carbon mass or layer with impregnant or other layer
• CPC Class Codes: Y10T 428/31678 Of metal

Abstract

A workpiece comprises a substrate having a sliding surface provided with a friction-reducing coating. Such coating consists essentially of elemental carbon dispersed in a matrix formed of at least one metallic element in the proportions of 50.1 to 99.1 at % of the elemental carbon and 0.1 to 49.9 at % of the metallic element. The ratio of the metallic element to the elemental carbon differs from the stoichiometric ratio of the carbide.

Claims

1. A workpiece comprising a substrate having a sliding surface provided with a friction-reducing coating;

said coating consisting essentially of elemental carbon dispersed in a matrix formed of at least one metallic element in the proportions of 50.1 to 99.9 at % of the elemental carbon and 0.1 to 49.9 at % of the metallic element, the ratio of the metallic element to the elemental carbon differing from the stoichiometric ratio of a carbide.

2. A workpiece according to claim 1, in which the substrate is metallic.

3. A workpiece according to claim 1, in which the coating consists essentially of 60 to 97 at % of elemental carbon and 40 to 3 at % of at least one metallic element.

4. A workpiece according to claim 3, in which the coating consists essentially of 80 to 95 at % of elemental carbon and 20 to 5 at % of at least one metallic element.

5. A workpiece according to claim 1, in which the metallic element is an element of group Ib, IIb, IIIa, IV, Vb, VIb, VIIb or VIII of the periodic table.

6. A workpiece according to claim 5, in which the metallic element is silicon, tantalum, tungsten, ruthenium or iron.

7. A method of making a workpiece according to claim 1, which includes coating the sliding surface of the substrate by chemical or physical vapour deposition of the elemental carbon and the metallic element.

8. A method according to claim 7, which includes depositing the elemental carbon and the metallic element by cathode sputtering of a target formed from carbon and the metallic element.

9. A method according to claim 7, which includes depositing the elemental carbon and the metallic element by cathode sputtering of a target formed from the metallic element in an atmosphere of an inert gas and a hydrocarbon gas.

10. A method according to claim 9, which includes starting the deposition in an atmosphere containing only the inert gas and then continuing the deposition under an inert gas-hydrocarbon gas atmosphere.

11. A method according to claim 9, in which the inert gas comprises argon.

12. A method according to claim 9, in which the hydrocarbon gas comprises acetylene. .Iadd.

13. A workpiece comprising:

a substrate having a surface; and

a friction-reducing coating on the surface of the substrate having a coefficient of sliding friction;

characterized in that the friction-reducing coating consists essentially of elemental carbon dispersed in a matrix formed by at least one metallic element, the ratio of carbon to the metallic element ranging from 50.1/49.9 to 99.9/0.1, said ratio differing from the stoichiometric ratio of a carbide. .Iaddend. .Iadd.

14. A workpiece as claimed in claim 13, characterized in that the friction-reducing coating is X-ray amorphous. .Iaddend. .Iadd.15. A workpiece comprising:

a substrate having a surface; and

a friction-reducing coating on the surface of the substrate, said friction-reducing coating having a coefficient of sliding friction;

characterized in that the friction-reducing coating consists essentially of elemental carbon dispersed in a matrix formed by at least one metallic element, the ratio of carbon to the metallic element ranging from 50.1/49.9 to 99.9/0.1 said ratio differing from the stoichiometric ratio of a carbide, said coating further containing impurities in amounts which do not materially increase the coefficient of sliding friction of the coating as compared to such a coating without such impurities. .Iaddend. .Iadd.16. A workpiece as claimed in claim 15, characterized in that the

15. friction-reducing coating is X-ray amorphous. .Iaddend. .Iadd.17. A system comprising:

a first workpiece having a surface;

a second workpiece having a surface, the surface of the first workpiece bearing against and sliding with respect to the surface of the second workpiece; and

a friction-reducing coating on the surface of the first workpiece;

characterized in that the friction-reducing coating consists essentially of elemental carbon dispersed in a matrix formed by at least one metallic element, the ratio of carbon to the metallic element ranging from 50.1/49.9 to 99.9/0.1 said ratio differing from the stoichiometric ratio of a carbide. .Iaddend. .Iadd.18. A system as claimed in claim 17, characterized in that the friction-reducing coating is X-ray amorphous. .Iaddend. .Iadd.19. A system as claimed in claim 18, further comprising a friction-reducing coating on the surface of the second workpiece.