Method of producing an anti-wear layer and anti-wear layer produced by means of said method

Patent metadata

Field	Value
Publication number	US-9803273-B2
Application number	US-201414787335-A
Country	US
Kind code	B2
Filing date	Apr 30, 2014
Priority date	Apr 30, 2013
Publication date	Oct 31, 2017
Grant date	Oct 31, 2017

Abstract

The invention relates to the production of wear-resistant layers which are exposed to friction wear on surfaces of components of internal combustion engines. In the process, wear-resistant layers are formed on the respective surface by electric arc discharge under vacuum conditions. The wear-resistant layers are formed from at least approximately hydrogen-free tetrahedrally amorphous (ta-C) comprising a mixture of sp2 and sp3 hybridized carbon and have a microhardness of at least 3500 HV and an arithmetical mean roughness value Ra of 0.1 μm without a mechanical, physical and/or chemical surface processing taking place.

First claim

We claim:

1. A method of producing wear-resistant layers on surfaces of components of internal combustion engines which are exposed to frictional wear, wherein a plasma is formed by means of pulse-operated laser radiation from sequentially ignited electrical arc discharges under vacuum conditions, wherein the electrical arc discharge is operated between an anode ( 6 ) and a cathode ( 10 ) of graphite and ionized parts of the plasma are deposited on a surface of at least one component ( 14 ) as a layer which is formed from at least approximately hydrogen-free tetrahedrally amorphous (ta-C) comprising a mixture of sp2 and sp3 hybridized carbon,
wherein the method further comprises deflecting the plasma by an absorber electrode ( 5 ) such that positively charged ions of the plasma are deflected in the direction of the at least one component ( 14 ) by applying at least approximately the same electric voltage at the anode ( 6 ) and at the absorber electrode ( 5 ) as the electrical arc discharges and providing an electric current flow through the absorber electrode ( 5 ) which is at least 1.5 times greater than the electric current flow through the anode ( 6 ), and
wherein said coated surface of the at least one component ( 14 ) is free of any mechanical and/or chemical machine finishing.

2. A method in accordance with claim 1 , characterized in that the electric current flowing through the absorber electrode ( 5 ) is at least two times greater than the electric current which flows through the anode ( 6 ).

3. A method in accordance with claim 1 , characterized in that the plasma is formed within a laser arc chamber ( 3 ) and is deflected into a vacuum chamber ( 1 ) in which the at least one component ( 14 ) is arranged.

4. A method in accordance with claim 1 , characterized in that positively charged ions of the plasma are deflected by means of the absorber electrode ( 5 ) such that they do not impact the surface of the at least one component ( 14 ) in a direct way starting from the cathode ( 10 ) and electrons move from the plasma in the direction of the absorber electrode ( 5 ).

5. A method in accordance with claim 1 , characterized in that a thin adhesive layer is deposited on the at least one component ( 14 ) using arc discharge source(s) or sputter source(s) ( 2 ) arranged in the vacuum chamber ( 1 ).

6. A method in accordance with claim 1 , characterized in that an absorber electrode ( 5 ) is used having a plurality of strips between which larger drops or droplets are led off so that they do not impact on the surface of the at least one component ( 14 ).

7. A method in accordance with claim 1 , characterized in that the wear-resistant layer has a microhardness of at least 3500 HV and an arithmetical mean roughness value Ra of 0.1 μm without a mechanical, physical and/or chemical surface processing having taken place.

8. A method as claimed in claim 7 , wherein the wear-resistant layer has a microhardness of at least 4000 HV.

9. A method as claimed in claim 7 , wherein the wear-resistant layer has a mean roughness depth Rz of a maximum of 1.0 μm.

10. A method as claimed in claim 7 , wherein the wear-resistant layer has a reduced peak height Rpk of a maximum of 0.35 μm.

11. A method as claimed in claim 7 , wherein the wear-resistant layer has a microhardness of at least 5000 HV.

Assignees

• Fraunhofer-Gesellschaft Zur Foerderung Der Angewandten Forschung E V
• H-O-T Haerte- Und Oberflaechentechnik Gmbh & Co Kg
• Fraunhofer Ges Forschung

Inventors

• Leson Andreas
• Scheibe Hans-Joachim
• Bach Frank-Peter

Classifications

• C23C28/322

  only coatings of metal elements only · CPC title

• C23C14/0605 Primary

  Carbon · CPC title

• C04B35/52

  based on carbon, e.g. graphite · CPC title

• H01J37/32055

  Arc discharge · CPC title

• C23C28/343

  with at least one DLC or an amorphous carbon based layer, the layer being doped or not · CPC title