WO2019110039A1

WO2019110039A1 - Layer system, component and method for layering

Info

Publication number: WO2019110039A1
Application number: PCT/DE2018/100926
Authority: WO
Inventors: Ladislaus Dobrenizki; Yashar Musayev; Valery Mitin; Pāvels NAZAROVS; Ricardo Henrique Brugnara; Ralf Winter
Original assignee: Schaeffler Technologies AG & Co. KG; Friedrich-Alexander-Universität Erlangen-Nürnberg
Priority date: 2017-12-04
Filing date: 2018-11-14
Publication date: 2019-06-13
Also published as: DE102017128724A1

Abstract

The invention relates to a layer system (1) comprising at least one wear protection layer (3) and a cover layer arranged on the wear protection layer (3), wherein the wear protection layer (3) is a nitridic hard material, wherein the cover layer is designed as a nanocomposite layer (4), wherein the nanocomposite layer (4) is a multiphase solid body layer, in which at least one phase, called the nanophase, is structured such that it measures less than 100 nm in at least one dimension, wherein a first phase (6, 7) formed from copper and a second phase (5, 8) formed from carbon are contained, and wherein the wear protection layer (3) and the nanocomposite layer (4) are formed by means of a physical vapor deposition method (PVD method). The invention furthermore relates to a component (10, 21, 22), particularly a chain link or chain bolt, comprising a metallic substrate (11) and a layer system (1), arranged at least in part on a surface of the substrate (11), wherein the wear protection layer (3) is arranged between the nanocomposite layer (4) and the substrate (11).

Description

Layer system, component and method for coating

The invention relates to a layer system comprising at least one

Wear protective layer. Another object of the invention relates to a component having a metallic substrate and the at least partially disposed on a surface of the substrate layer system.

From DE 10 2005 047 449 A1, a layer system for protecting a link chain against wear and to increase energy efficiency is known. This

Layer system has a wear protection layer, which is formed as a nitridic or non-nitride hard material layer and directly on the

Function surface of the chain pin is deposited. On this hard

Wear protection layer is provided to reduce the friction, a sliding layer, made of a soft metal, M0S2, WS2 or from a

Polymer layer is formed. With such a layer system, the wear of the elements of the link chain can be reduced. However, it is desirable to further improve wear protection for highly stressed components.

US 5,108,813 A describes a sliding element with a ceramic or metallic substrate and a diamond film on the surface of the substrate, wherein the diamond film is patterned and the recesses are filled with a soft metal.

DE 10 2005 014 484 B4 discloses a roller chain which has a hard carbide layer in some areas.

DE 10 2006 024 433 A1 describes a wear-resistant chain with a

Wear protection coating at least partly nanocrystalline structure. In this case, nano-sized hard material particles are dispersed in a matrix. Among other things, a metal matrix of copper and / or tungsten and / or zinc and / or tin is described, in which nanocrystals of zirconium nitride and / or

Alumina and / or silicon nitride and / or titanium dioxide are located. EP 3 053 968 B1 discloses a nanocomposite coating of solid lubricant, wherein layer layers of a carbon matrix with

Copper grains with other intermediate layers of metal, here in the form of titanium, zirconium, hafnium or vanadium, alternate.

Against this background, the task arises to improve the tribological behavior, in particular the wear protection.

The object is achieved by a layer system comprising at least one

Wear protection layer and disposed on the wear protection layer cover layer in the form of a solid lubricant layer, wherein the

Wear protection layer is a nitridic hard material layer, wherein the cover layer is formed as a nanocomposite layer, wherein the nanocomposite layer is a multi-phase solid state layer in which at least one phase, called

Nanophase, is structured so that they in at least one dimension a

Dimension smaller than 100 nm, wherein a first phase of copper and a second phase of carbon are contained, and wherein the

Wear protection layer and the nanocomposite layer by means of a physical vapor deposition (PVD) process are formed.

It has been found that by the layer system according to the invention a reduced compared to the prior art wear of friction partners can be achieved, the friction between the friction partners is not increased. The cover layer of copper-carbon nanocomposite reduces the friction. The anti-wear layer in the form of the nitridic hard material layer, which is arranged underneath the nanocomposite layer, provides protection against abrasive wear.

For the purposes of the invention, a nanocomposite layer is understood to mean a multiphase solid state layer in which at least one phase is structured such that it has a dimension smaller than 100 nm in at least one dimension, in particular in the range from 10 nm to 99 nm, for example in the region of 10 nm to 70 nm. In particular, this nanophase is structured such that in each dimension it has a dimension smaller than 100 nm, in particular in the range of 10 nm to 99 nm, for example in the range of 10 nm to 70 nm. The The nanocomposite layer according to the invention has at least two phases, wherein a first phase is copper and a second phase is carbon. The phases are formed in particular by copper particles or carbon particles.

The nanocomposite layer preferably has a content of copper and carbon which, in total, is greater than 70 atomic%, preferably greater than 80 atomic%, particularly preferably greater than 90 atomic%.

According to the invention, the wear protection layer is formed as a nitridic hard material layer, in particular as a stoichiometric chromium nitride layer or a non-stoichiometric chromium nitride layer (CrN or Cr2N) or a combination thereof. Alternatively, the wear protection layer may be formed as a chromium nitride-based layer.

It is advantageous if the wear protection layer has a nitrogen content which is less than or equal to 60 atomic%, preferably less than 60 atomic%.

The wear protection layer preferably has a layer thickness in the range from 2.0 μm to 5.0 μm.

The wear protection layer preferably directly adjoins the as

Nanocomposite layer formed on top layer. This means that no further layers between the wear protection layer and the

Nanocomposite layer are present.

An advantageous embodiment provides that the nanocomposite layer stores a carbon matrix as the second phase and in the carbon matrix

Copper particles as the first phase and nanophase has. The carbon matrix can be present, for example, as a graphite matrix in which the copper particles are incorporated.

According to an alternative, advantageous embodiment, it is provided that the nanocomposite layer has a copper matrix as the first phase and carbon particles embedded in the copper matrix as the second phase and nanophase. The Carbon particles may exist as graphite particles embedded in the copper matrix.

It is preferred if the copper particles or the carbon particles have a particle size in the range of less than 100 nm, preferably in the range of 10 nm to 99 nm,

particularly preferably in the range of 10 nm to 70 nm.

An advantageous embodiment provides that the nanocomposite layer has oxygen, wherein the content of oxygen is less than 30 atomic%, preferably less than 20 atomic%.

Alternatively or additionally, the nanocomposite layer may comprise nitrogen, wherein the content of nitrogen in the nanocomposite layer is less than 10 atom%, preferably less than 5 atom%.

According to a preferred embodiment, a content of metals other than copper in the nanocomposite layer is less than 0.01 atom%, preferably less than 0.001%, more preferably the nanocomposite layer is free of metals other than copper. Alternatively, it can be provided that the nanocomposite layer has one or more intermediate layers which are formed from a metal other than copper. Preferably, the other metal is titanium (Ti), zirconium (Zr), hafnium (Hf), molybdenum (Mo), aluminum (Al), chromium (Cr), tungsten (W), niobium (Nb), tantalum (Ta) or Vanadium (V).

An advantageous embodiment provides that the nanocomposite layer a

Layer thickness in the range of 1, 0 pm to 10.0 pm, preferably in the range of 0.5 pm to 2.5 pm.

The layer system preferably has a layer thickness in the range from 0.6 μm to 21.0 μm, preferably in the range from 2.5 μm to 8.5 μm, particularly preferably in the range from 3.0 μm to 5.0 μm.

It is advantageous if the wear protection layer has a Vickers hardness in the range from 1000 to 4000 HV and the nanocomposite layer has a Vickers hardness of less have 1500 HV. As a result, high wear protection of the friction partners can be achieved.

According to an advantageous embodiment, the layer system further comprises a metallic adhesion promoter layer, which is arranged opposite to the cover layer adjacent to the wear protection layer. By adhesion promoter layer, the adhesion of the layer system to a substrate, in particular a

metallic substrate, to be improved. The adhesive layer has

in particular chromium and / or titanium and / or aluminum and / or niobium and / or vanadium and / or molybdenum or a combination thereof. The adhesion promoter layer particularly preferably consists of chromium and / or titanium.

Another object of the invention is a component comprising a metallic substrate and at least partially disposed on a surface of the substrate layer system, which is formed as described above, wherein the

Wear protection layer between the nanocomposite layer and the substrate is arranged.

The metallic substrate is preferably formed from steel. For example, the steel may be made of 16MnCr5, C45, C60, 100Cr6, 31 CrMoV9, 80Cr2 steel,

34CrAIMo5-10 or 42CrMo4 be formed.

Preferably, the component is an engine element of an internal combustion engine,

in particular a chain element, for example a chain pin, an element of the valvetrain, for example a rocker arm, a rocker arm or a bucket tappet, or a sliding or roller bearing, or a toothed wheel. Preferably, the component is a chain element of a sleeve chain or a toothed chain or a roller chain.

According to a preferred embodiment, the layer system comprises a

Adhesive layer disposed adjacent to the wear protection layer and disposed adjacent to the substrate. The provision of a

Adhesive layer can improve the adhesion of the layer system to the metallic substrate. The adhesion promoter layer particularly preferably has chromium and / or titanium. According to the invention it is provided that the wear protection layer and the

Nanocomposite layer, by physical vapor deposition (English physical vapor deposition, PVD) are deposited. Furthermore, the

Adhesive layer be applied by physical vapor deposition or alternatively by means of another application method, such as a chemical

Chemical vapor deposition (CVD), electrodeposition, electroless plating, etc.

In particular, it has proven useful if the nanocomposite layer is produced by means of a mosaic target in a PVD process by sputtering. See, for example, EP 0 634 499 A1. A mosaic target has a combination of at least two materials in solid form, such as plate, pie, bar, etc., where the materials can be removed from the mosaic target and simultaneously deposited on a substrate. Depending on the setting of the PVD deposition process a different one

Adjustable composition of the deposited layer, which is not possible, for example, when using an alloy composition as a target material. Here in particular copper plates and carbon plates to a

Mosaic target composed. This results in a very homogeneous mixing of the materials carbon and copper in the deposition process, so that no

Nanolagen of carbon and copper are detectable in the nanocomposite layer, but a homogeneous mixture of copper and carbon as

Solid lubricant layer is present.

As a method for coating a component comprising a substrate, it is proposed that a wear protection layer in the form of nitridic

Hard material layer is deposited at least partially on a surface of the substrate by means of physical vapor deposition, and on the

Wear protection layer a cover layer by means of physical

Deposited vapor deposition, wherein the cover layer as

Nanocomposite layer is formed, which has copper and carbon. In the method, the same advantages can be achieved as they have already been described in connection with the layer system according to the invention.

For physical vapor deposition (PVD), the methods sputtering or arc evaporation or a combination thereof are preferably used. Before the wear protection layer is applied to the substrate, an adhesion promoter layer may optionally be provided by means of physical adhesion

Gas phase deposition are deposited directly on the substrate. The

Adhesion promoter layer may comprise, for example, chromium, titanium and / or aluminum and / or niobium and / or vanadium and / or molybdenum or a combination thereof. The adhesion promoter layer particularly preferably consists of chromium and / or titanium.

In order to form the adhesion promoter layer and / or the wear protection layer and / or the nanocomposite layer, the component can be arranged on a component holder which is rotated in a vacuum chamber about an in particular vertical axis (PVD batch system). Within the vacuum chamber different targets can be arranged. For example, a first target for forming the adhesion promoter layer, a second target for forming the

Wear protection layer and a third target to form the nanocomposite layer may be provided. The target for forming the nanocomposite layer is preferably formed as a common carbon-copper target comprising both copper and carbon. For example, the common target may be a mosaic target or an alloy target.

Alternatively, to form the adhesion promoter layer, the wear protection layer and / or the nanocomposite layer, a continuous flow system (PVD in-line system) for PVD coating can be used, in which the component is transported in a transport direction through a vacuum chamber. Optionally, the component can be rotated in addition to the movement in the transport direction about a rotation axis, in particular a longitudinal axis of the component. Further details and advantages of the invention will be explained below with reference to the embodiment shown in the drawings. Hereby shows:

1 shows a first embodiment of a component with a layer system according to the invention in a schematic sectional view;

Fig. 2 shows a second embodiment of a component with a

Layer system according to the invention in a schematic

Section;

3 shows a third embodiment of a component with a layer system according to the invention in a schematic sectional view; and

Fig. 4 shows a fourth embodiment of a component according to the invention in a perspective sectional view.

1 shows a first exemplary embodiment of a component 10 which has a layer system 1 according to the invention whose layers 2, 3, 4 have been formed by means of physical vapor deposition. The substrate 11 of the component 10 is formed of a steel, for example of 16MnCr5, C45, C60, 100Cr6, 31 CrMoV9, 80Cr2 or 42CrMo4 steel. On the substrate 11 is at least partially an adhesive layer 2 with the layer thickness di

deposited. The adhesion promoter layer 2 is preferably made of chromium and / or titanium. About the directly adjacent to the substrate 11 adhesive layer 2 is a material connection to the, also adjacent to the adhesive layer 2 wear protection layer 3 is formed. The layer thickness di the

Adhesive layer 2 is in the range of 0.01 pm to 1, 0 pm.

The wear protection layer is 3 of stoichiometric or not

stoichiometric chromium nitride or a combination thereof and has a high hardness, so that the underlying substrate 11 is very well protected against wear. The layer thickness d2 of the wear protection layer 3 is in the range of 2.0 pm to 5.0 pm. On the wear protection layer 3, immediately adjacent to the wear protection layer 3, a nanocomposite layer 4 is deposited, which is formed as a copper-carbon nanocomposite. The nanocomposite layer 4 is substantially biphasic. This means that the nanocomposite layer 4, apart from the main constituents copper and carbon, only small amounts of others

Contains elements, in the present case, primarily low levels of oxygen and / or nitrogen. The content of these elements is in the range of less than 30 atomic%, preferably less than 20 atomic%, more preferably less than 10 atomic%. According to the first embodiment, the nanocomposite layer 4 has a first phase 5 in the form of a carbon matrix and one in the carbon matrix

embedded second phase 6 in the form of copper particles. The second phase is therefore the nanophase. The grain size of these copper particles is in the range of less than 100 nm, preferably between 10 nm and 70 nm. The carbon matrix is formed of carbon. The layer thickness d3 of the nanocomposite layer 4 is in the range from 0.1 μm to 10.0 μm, preferably in the range from 0.5 μm to 2.5 μm.

The nanocomposite layer 4 forms a covering layer cooperating with the respective friction partner of the component 10, which improves the tribological behavior, in particular reduces the wear.

FIG. 2 shows a second exemplary embodiment of a component 10 which has a layer system 1 according to the invention. The layer system according to the second embodiment essentially has the features of

Layer system according to the first embodiment, differs from the layer system of the first embodiment in the configuration of the nanocomposite layer 4. In the second embodiment, the

Nanocomposite layer 4 has a second phase 7 in the form of a copper matrix and embedded in the copper matrix on a first phase 8 in the form of carbon particles.

The carbon particles have a particle size in the range of less than 100 nm, preferably between 10 nm and 70 nm, and form the nanophase.

Fig. 3 shows a third embodiment of a component 10 with a

Layer system 1 according to the invention. In contrast to the layer system 1 according to the first embodiment, the layer system 1 according to the third embodiment, no adhesive layer on. The

Wear protection layer 3 of this layer system 1 is deposited directly adjacent to the substrate 11. In this respect, the wear protection layer 3 adjoins both the substrate 11 and the nanocomposite layer 4 and is provided between them.

4 is a perspective, partially sectioned view of a link chain 20 is shown with components according to the invention, as a chain link 21,

22 or chain pin 26 are configured. The link chain 20 can be used as part of a chain drive, for example an internal combustion engine. The chain 20 has a plurality of chain links 21, 22 which are pivotally connected to each other via chain pins 22. For this purpose, the chain links 21, 22 at least two recesses 24 through which a chain pin 26 is guided.

The chain 20 comprises inner chain links 22, in whose recesses 24 a sleeve

23 is arranged, for example by means of interference fit. The chain pin 26 is disposed within the sleeve 23 and forms a friction pair with the sleeve 23 of the inner chain link 22. In the chain 20 shown in FIG. 4, the recesses 25 of the outer chain links 21 are formed with a smaller diameter than the

Recesses 24 of the inner chain links 22. The chain pin 26 is also disposed within the recess 25 of an outer chain link 21 and connected to the outer chain link 25, in particular by means of interference fit.

To reduce the friction and the wear of the friction pair is the

Chain pin 26 of the link chain 20 with a layer system 1 according to the invention, for example, a layer system as shown in Fig. 1, 2 or 3, coated. Alternatively or additionally, the inner contour of the sleeves 23 of the inner chain links 22 and / or the inner contour of the recesses 25 of the outer chain links 21 may be coated with a layer system according to the invention. Particularly preferably, the chain pin 25 and / or the inner contour of the sleeve 23 and / or the inner contour of the recess 25 on an identical layer system 1. Alternatively or additionally, the outer contour of the outer chain link 21 and / or the

Outer contour of the inner chain link 22 with the layer system 1 according to the invention Be provided, for example, the friction against a

To reduce chain guide rail.

According to a modification of the roller chain shown in Fig. 4, the link chain 20 is formed as a sleeve chain or a toothed chain.

The components described above each have at least partially a layer system 1 comprising at least one wear protection layer 3 in the form of a nitridic hard material layer and a cover layer arranged on the wear protection layer 3, which is formed as a nanocomposite layer 4 of predominantly copper and carbon in the form of a solid lubricant layer.

The described components 10, 21, 22, 26 are provided with a

A vacuum coating method coated in which on a surface of the substrate 11 of the component 10, 21, 22, 26 a wear protection layer 3 is deposited by means of physical vapor deposition. On the

Wear protection layer 3, a nanocomposite layer 4 is deposited by means of physical vapor deposition in a subsequent process step. Optionally, in an intermediate step by means of physical

Vapor deposition initially an adhesive layer are applied to the substrate 11, before the wear protection layer 3 is deposited.

LIST OF REFERENCE NUMBERS

1 layer system

2 adhesion promoter layer

3 wear protection layer

4 nanocomposite layer

5, 8 first phase

6, 7 second phase

10 component

11 substrate

20 chain

21 outer link

22 inner chain link

23 sleeve

24 recess

25 recess

26 chain pins

D layer thickness of the layer system di layer thickness of the adhesion promoter layer d2 layer thickness of the wear protection layer d3 layer thickness of the nanocomposite layer

Claims

claims

1. Layer system (1) comprising at least one wear protection layer (3) and a covering layer on the wear protection layer (3) in the form of a solid lubricant layer, wherein the wear protection layer (3) is a nitridic Flartstoffschicht, wherein

the cover layer is formed as a nanocomposite layer (4), wherein the nanocomposite layer (4) is a multi-phase solid state layer in which at least one phase, called nanophase, is structured such that it has a dimension smaller than 100 nm in at least one dimension, wherein a first phase (6, 7) of copper and a second phase (5, 8) of carbon are contained, and wherein the wear protection layer (3) and the nanocomposite layer (4) by means of a physical

Gas phase deposition method (PVD method) are formed.

Second layer system (1) according to claim 1, characterized in that the

Wear protection layer (3) is formed as a stoichiometric chromium nitride layer or a non-stoichiometric chromium nitride layer or a combination of both.

3. Layer system (1) according to one of the preceding claims, characterized

in that the wear protection layer (3) has a nitrogen content which is less than 60 atomic%.

4. Layer system (1) according to any one of the preceding claims, characterized

in that the nanocomposite layer (4) has a carbon matrix as the second phase (5) and copper particles incorporated in the carbon matrix as the first phase (6) and nanophase.

5. Layer system (1) according to one of claims 1 to 3, characterized

in that the nanocomposite layer (4) has a copper matrix as the first phase (7) and carbon particles incorporated in the copper matrix as the second Phase (8) and nanophase has.

6. layer system (1) according to any one of the preceding claims, characterized

in

the nanocomposite layer (4) comprises oxygen, the content of oxygen being less than 30 atomic%, preferably less than 20 atomic%, and / or

the nanocomposite layer (4) comprises nitrogen, the content of nitrogen being less than 10 atom%, preferably less than 5 atom%.

7. Layer system (1) according to one of the preceding claims, characterized

in that the nanocomposite layer (4) has a layer thickness (d3) in the range from 0.1 μm to 10 μm, preferably in the range from 0.5 μm to 2.5 μm.

8. Layer system (1) according to one of the preceding claims, characterized

in that the layer system (1) has a layer thickness (D) in the range from 0.6 μm to 21.0 μm, preferably in the range from 2.5 μm to 8.5 μm, particularly preferably in the range from 3.0 μm to 5 μm, 0 pm.

9. Layer system (1) according to one of the preceding claims, characterized

characterized in that the layer system (1) is a metallic

Adhesive layer (2), which is arranged opposite to the cover layer adjacent to the wear protection layer (3).

10. layer system (1) according to claim 9, characterized in that the

Adhesive layer (2) comprising chromium and / or titanium and / or

Aluminum and / or niobium and / or vanadium and / or molybdenum or a combination of these elements is formed.

11. Layer system (1) according to one of the preceding claims, characterized

in that the layer system (1) is formed overall by means of a physical vapor deposition method (PVD method).

12. component (10, 21, 22, 26), in particular chain link or chain pin, comprising a metallic substrate (11) and at least partially on a surface of the substrate (11) arranged layer system (1) according to one of the preceding claims, wherein the Wear protection layer (3) between the nanocomposite layer (4) and the substrate (11) is arranged.