CA2171585A1 - Part having an electrodeposited coating and process for producing electrodeposited layers - Google Patents
Part having an electrodeposited coating and process for producing electrodeposited layersInfo
- Publication number
- CA2171585A1 CA2171585A1 CA 2171585 CA2171585A CA2171585A1 CA 2171585 A1 CA2171585 A1 CA 2171585A1 CA 2171585 CA2171585 CA 2171585 CA 2171585 A CA2171585 A CA 2171585A CA 2171585 A1 CA2171585 A1 CA 2171585A1
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- Prior art keywords
- nanoparticles
- electroplating bath
- metal layer
- coating
- metallic
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- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25D15/00—Electrolytic or electrophoretic production of coatings containing embedded materials, e.g. particles, whiskers, wires
- C25D15/02—Combined electrolytic and electrophoretic processes with charged materials
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Electroplating Methods And Accessories (AREA)
- Other Surface Treatments For Metallic Materials (AREA)
Abstract
Part having an electrodeposited coating and process for producing electrodeposited layers The object is to produce a part (1) having an electrodeposited coating which is resistant to mechanical abrasion and which can be produced comparatively easily, the coating being formed in such a way that, if it is used as a component of a contact system, it makes an additional lubrication of the latter unnecessary, and to provide a simple process for producing said electrodeposited coating.
This is achieved by incorporating in at least one metallic layer of the coating homogeneously dis-tributed nanoparticles (4) which are chemico-physically joined to at least one substance which reduces the abrasion or the friction.
This is achieved by incorporating in at least one metallic layer of the coating homogeneously dis-tributed nanoparticles (4) which are chemico-physically joined to at least one substance which reduces the abrasion or the friction.
Description
~171~85 `~ Se 8.6.95 95/068 TITLE OF THE INVENTION
- Part having an electrodeposited coating and process for producing electrodeposited layers BACKGROUND OF THE INVENTION
Field of the invention The invention proceeds from a part having an - electrodeposited coating in accordance with the preamble of claim 1 and from a process for producing electrodeposited layers.
Discussion of background Electroplated parts and a multiplicity of processes for producing electrodeposited layers are known. For example, Offenlegungsschrift DE 23 58 309 discloses such a process in which fine-grained particles are kept in suspension in the electroplating bath. Said fine-grained particles are introduced mechanically into the metallic layer produced by electroplating and are enclosed by the deposited metal as the electroplating process proceeds. The introduc-tion of the fine-grained particles into the metal layer requires a comparatively high mechanical expenditure.
The paper entitled "Erhohung der Verschleissfestigkeit versilberter Gleitkontakte durch Dispersionsbeschichtungen" ("Increasing the wear resistance of silver-plated sliding contacts by dispersion coatings") by V. Sova and H. Bollhalder which appeared in the journal entitled "Oberflache surface" 1987, No. 9, pages 13 to 15 discloses the fact that the incorporation of particles foreign to the metal in a silver matrix reduces the adhesion wear of the electrodeposited layers thus obtained. Said particles foreign to the metal may be oxides, carbides, sulfides or other metals, and they have a particle size in the range between 0.5 ~m and 8 ~m. The proportion by volume of said particles foreign to the metal was in-the range between 1~ and 5~. This dispersion coating resulted in an improvement in the adhesion wear in the ~ i 715 ~ 5 case of silver contact systems, but such contact systems can be used only if they are additionally lubricated from time to time with conventional lubricants. The surface of such coatings is comparatively rough since, on the one hand, the sharp-edged particles foreign to the metal project out of the surface in places and, on the other hand, the sharp-edged particles foreign to the metal cause pores in the coating. The respective lubricant deposits in the depressions in this surface and is consumed together with the erosion occurring during operation of the rouyh areas of the surface, and then has to be replaced.
SUMMARY OF THE INVENTION
As it is characterized in the independent claims, the invention achieves the object of producing a part which has an electrodeposited coating and which is comparatively simple to produce, the coating being formed in such a way that, if it is used as a component of a contact system, it makes an additional lubrication of the latter unnecessary, and to provide a simple process for producing said electrodeposited coating.
The advantages achieved by the invention are essentially to be perceived in the fact that the coating has a better stability with respect to mechanical stresses. It is a substantial~~ economic advantage that these coatings can be produced in conventional electroplating plants without additional mechanical expenditure.
The further refinements of the invention are subjects of the dependent claims.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying ~1715~5 drawings, which show only one method of implementation and wherein:
Figure 1 shows a partial section through a part having a coating according to the inven~ion, Figure 2 shows a section through a nanoparticle, Figure 3 shows a simplified block diagram of a process according to the invention, and Figure 4 shows a simplified block diagram of a further process according to the invention.
All the elements not required for an immediate understanding of the invention are not shown.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views, Figure 1 shows a partial section, depicted in considerably simplified form, through a part 1 having a coating according to the invention. The part 1 may be of cylindrical design, but it may also have a flat surface which is provided with a coating. The part 1 has a basic material 2 composed of a metal or of a plastic. If the basic material 2 is a plastic matrix, its surface to be coated is metallized before it is introduced into an electroplating bath, for example by chemical deposition of a metal layer on said surface or by vapor deposition of a metal layer under high-vacuum conditions.
Electrodeposited on the basic material 2 is a first metal layer 3 in which homogeneously distributed nanoparticles 4 are incorporated. Said nanoparticles 4 are chemico-physically joined to a substance which reduces the abrasion or the friction. Said substance which reduces the abrasion or the friction is a substance based on surface-active chemical compounds.
Said first metal layer 3 may also be composed of a plurality of consecutively deposited individual layers.
For certain applications, the first metal layer does not need to be coated with further layers. Here, however, the first metal layer 3 is completely coated 2171~85 _ _ 4 _ 95/068 with a metallic top layer 5. The top layer 5 has a smooth surface 6. The metallic top layer 5 has, as a rule, a greater hardness than the first metal layer 3.
For a fixed or comparatively slowly moving component of a silver-plated contact system, it has been found that the first metal layer 3 advantageously has a thickness in the range from 5 ~m to 15 ~m, where-as the metallic top layer 5 has a thickness in the region around 2 ~m. In this connection, the metallic top layer 5 is advantageously formed as a hard silver plating in order to thereby optimize its abrasion behavior.
Depending on the planned field of application of the coating, various, suitably prepared substances can be used as nanoparticles 4, for example carbides such as SiC, WC and TiC, nitrides such as AlN and Si3N4, borides such as TiB, metal oxides such as ZnO, SiO2, Fe2O3, Bi2O3, PdO, NiO, AgO, TeO, CuO, Sb2O3, TiO2, ZrO2, Al2O3, In2O3, SnO, V2O5, TiO2 and MgO and metals such as, for example W and Ni. The nano-particles 4 are produced from the respective basic materials with the aid of one of the known processes.
The nanoparticles 4 have a size in the range from about 5 nm to 50 nm and as a rule, they are spherically formed. The nanoparticles 4 do not have sharp edges.
Nanoparticles 4 composed of a single substance or nanoparticles 4 composed of a mixture of two or more substances are introduced into the electroplating bath.
To achieve a uniform distribution of the nanoparticles 4 in the electroplating bath, the bath is continuously stirred.
If particles are used which have a somewhat coarser structure than the nanoparticles 4 described above, then, although the chemico-physical effective-ness of said particles is somewhat impaired since fewersurface-active chemical compounds may attach themselves to said particles, applications are quite conceivable in which such a coarser structure can advantageously be used. In particular, it is also possible to use ~71585 particles which have a somewhat coarser structure mixed with nanostructured material in order to achieve a specific adaptation to certain specified operating requirements in this way.
As surface-active chemical compounds suitable for attachment to the nanoparticles 4, use may be made of bipolar natural chemical compounds which are referred to as soaps such as, for example, stearates, oleates, palmitates and laureates but synthetic compounds may also be used, such as, for example, sulfonic acids, and in this connection, in particular, toluenesulfonic acid and laurinsulfonic acid, or aminoalcohols, polyalcohols and the like. These compounds attach themselves chemico-physically to the nanoparticles 4, and, as a rule, it is van der Waals' forces which provide for this attachment. The nanoparticles 4 are completely or at least partially enveloped by one of these compounds or by a mixture of two or more of these compounds which reduce the abrasion or the friction.
Figure 2 shows diagrammatically a section through a nanoparticle 4 with its envelope of a surface-active chemical compound attached chemico-physically. The nanoparticle 4 has been produced, for example, from Al2O3, ZrO or TiO2 by one of the known methods. Oxygen O is attached directly to the nanoparticle 4 and a hydrocarbon compoun-d R1 is attached to the oxygen O. Attached here to the hydrocarbon compound R1 is, for example, an amino alcohol NH2 which is to be regarded as the decisive component for the reduction of the abrasion or of the friction when said nanoparticle 4 is incorporated in the first metal layer 3. Additionally, however, hydroxyl groups OH are directly attached to the nanoparticle 4, the hydrogen for said hydroxyl groups being obtained by the attached oxygen O from the water of the electroplating bath. The hydrogen ions of said hydroxyl groups OH are positively charged so that the nanoparticle 4 has, on the whole, a positive electrical - 21715~
~ - 6 - 95/068 charge. The nanoparticles 4 positively charged in this way migrate to the cathode in the electrical field of the electroplating bath, just like the dissolved metals, and are deposited there together with the latter on the part 1 to be coated. In this way, a very homogeneous distribution of the nanoparticles 4 in the first metal layer 3 is achieved without additional aids, which results in a uniform lubricating action by the envelope of the incorporated nanoparticles 4.
The non-oxidic nanoparticles 4 having nitrides, borides, carbides and metals as basic substances are also coated in normal atmosphere with a very thin oxide layer which, after said nanoparticles 4 have been introduced into an electroplating bath, makes possible the same chemico-physical surfaces reactions as those described above in connection with the depiction of the nanoparticle 4 in Figure 2.
Many of these compounds are already used as wetting agents in conventional electroplating baths, but their additional advantageous possible use as means for the reduction of the abrasion or the friction could not be exploited hitherto. It is only as a result of the combination with the nanoparticles 4 which permit an attachment of these compounds in an amount sufficient for a good lubrication by chemico-physical means and which do not themselves have edges which could again destroy the lubricating action thus produced that the advantageous reduction of the abrasion or of the friction is fully realized. The first metal layer 3 is accordingly to be considered as a layer with a self-lubricating action.
Such coatings can advantageously be used as contact surfaces in contact systems. A multiplicity of specific applications of said coatings can be conceived. In a contacting assembly, the coated part 1 may interact as stationary or comparatively slowly moving component with a mobile metallic component which slides or rolls off on said part 1. The part 1 may be formed, for example, as fixed rated-current contact of 7~535 _ 7 _ 95/068 a circuit breaker and a mobile countercontact equipped with silver-plated fingers or silver-plated spiral contacts may be provided as component which slides on said stationary contact. On the one hand, the contact junctions in circuit breakers and in power distribution plants can be improved by these novel silver-plated contacts, and on the other hand, the gold-coated contact areas, for example, in relays can also be made more durable or, given the same service life, be provided with a thinner coating, which results in considerable material savings, given the enormous number of pieces of such contacts.
For use in silver-plated contact zones in metal-enclosed gas-insulated switchgear assemblies filled with SF6 gas, use can be made particularly advantageously of nanoparticles 4 based on carbides and metals and prepared by one of the known processes.
Said nanoparticles 4 have a size of approximately 5 nm to 50 nm. Said nanoparticles 4 are resistant to the decomposition products of the sulfur hexafluoride which is, as a rule, used in said metal-enclosed gas-insulated switchgear assemblies as insulant and as quenching agent for the arc, so that the lubricating capability of the first metal layer 3 is not reduced by said decomposition products. A particularly long service life of the contacts is achieved by the compounds attached to said nanoparticles --4. The abrasion which occurs here comprises comparatively small abrasion particles, and no abrasion particles of critical size occur which could migrate in the electrical field prevailing in the metal-encapsulated gas-insulated high-voltage plants and cause flashovers.
Such coatings can also be advantageously used as surfaces for sliding bearings or other mechaniçally stressed bearings. In a bearing, the part 1 is formed as fixed or comparatively slowly moving component which interacts with a mobile metallic compound which slides or rolls off on said part 1.
- 21~158~
~ - 8 - 95/068 It is also possible to provide consumer products such as, for example, cutlery, jewellery, plastic costume jewellery and the like with the coating according to the invention in order to improve their durability or to save material for the coating. In the case of silver-plated cutlery, the first metal layer 3 is provided, as described, with nanoparticles 4 together with the abrasion-reducing attachments and the top layer 5 on top thereof is a high-polished silver plating.
In the course of time said top layer 5 will chafe through at the most stressed points, so that the first metal layer 3 is laid bare. Due to the doping with the enveloped nanoparticles 4, however, said first metal layer 3 is so abrasion-resistant that the further wear of the cutlery is slowed down considerably, while the visual impression of the cutlery is impaired only slightly.
The process for producing abrasion-resistant electrodeposited layers on parts 1 comprises the following process steps:
a) introduction of nanoparticles into a first electroplating bath, which is continuously stirred, b) introduction of particles which attach themselves to said nanoparticles and which are composed of a substance based on surface-active chemical compounds into the first electroplating bath, c) introduction of a part 1 to be coated into the first electroplating bath, d) performance of an electrolytic coating process until a first, predominantly metallic layer is deposited on the part 1, and e) removal of the part 1 from the electroplating bath.
The part 1 is now coated with the first metal layer 3. Said first metal layer 3 may be built up as a single-layer structure or, alternatively, of a ~ 171~85 plurality of similar layers. In principle, it is also possible to build up said first metal layer 3 from a plurality of layers of various metals, each of said layers being doped, however, with nanoparticles 4. If said first metal layer 3 is used in a bearing, a coating with an additional top layer 5 is not, as a rule, provided. The full effect of the compounds with lubricating action attached to the nanoparticles 4 is thus ensured from the start.
If the coated part 1 is used, for example, for a contact system, the first metal layer 3 is coated with a metallic top layer 5 and the process steps below follow the process steps already listed above:
f~ introduction of the coated part 1 into a second electroplating bath, g) performance of at least one further electrolytic coating process until a second metallic top layer 5 completely covering the first layer is deposited on the part 1, and h) removal of the part 1 coated with two layers from the second electroplating bath.
In most cases, the same metal is dissolved in the first and in the second electroplating bath, but it is also possible, if specific applications require it, for at least two different metals to be dissolved in one or even in both electroplating baths. The hardness of the respective metal layer can thus be adapted by simple means to the respective operating requirements.
Into the first electroplating bath, 0.002 to 0.20 percent by weight of the nanoparticles 4 are introduced. It has been found that an optimum composition of the first metal layer 3 is then obtained. Of the substance based on surface-active chemical compounds, a comparatively small amount, matched to the amount of the nanoparticles 4, is introduced into the first electroplating bath, and in this connection, care is taken that said substance is continuously added. If the amounts of the nanoparticles 4 and of said substance are not matched ~ L 7 .L 5 ~ 5 _ - 10 - 95/068 to one another, an undesirable clotting of the nanoparticles 4 frequently occurs, which has the consequence that these clots settle in the electroplating bath and the homogeneous distribution of the nanoparticles 4 in the first metal layer 3 is then no longer ensured. If attention is paid to the matching of the amounts mentioned, however, the concentration of the electroplating bath is not appreciably affected.
Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.
- Part having an electrodeposited coating and process for producing electrodeposited layers BACKGROUND OF THE INVENTION
Field of the invention The invention proceeds from a part having an - electrodeposited coating in accordance with the preamble of claim 1 and from a process for producing electrodeposited layers.
Discussion of background Electroplated parts and a multiplicity of processes for producing electrodeposited layers are known. For example, Offenlegungsschrift DE 23 58 309 discloses such a process in which fine-grained particles are kept in suspension in the electroplating bath. Said fine-grained particles are introduced mechanically into the metallic layer produced by electroplating and are enclosed by the deposited metal as the electroplating process proceeds. The introduc-tion of the fine-grained particles into the metal layer requires a comparatively high mechanical expenditure.
The paper entitled "Erhohung der Verschleissfestigkeit versilberter Gleitkontakte durch Dispersionsbeschichtungen" ("Increasing the wear resistance of silver-plated sliding contacts by dispersion coatings") by V. Sova and H. Bollhalder which appeared in the journal entitled "Oberflache surface" 1987, No. 9, pages 13 to 15 discloses the fact that the incorporation of particles foreign to the metal in a silver matrix reduces the adhesion wear of the electrodeposited layers thus obtained. Said particles foreign to the metal may be oxides, carbides, sulfides or other metals, and they have a particle size in the range between 0.5 ~m and 8 ~m. The proportion by volume of said particles foreign to the metal was in-the range between 1~ and 5~. This dispersion coating resulted in an improvement in the adhesion wear in the ~ i 715 ~ 5 case of silver contact systems, but such contact systems can be used only if they are additionally lubricated from time to time with conventional lubricants. The surface of such coatings is comparatively rough since, on the one hand, the sharp-edged particles foreign to the metal project out of the surface in places and, on the other hand, the sharp-edged particles foreign to the metal cause pores in the coating. The respective lubricant deposits in the depressions in this surface and is consumed together with the erosion occurring during operation of the rouyh areas of the surface, and then has to be replaced.
SUMMARY OF THE INVENTION
As it is characterized in the independent claims, the invention achieves the object of producing a part which has an electrodeposited coating and which is comparatively simple to produce, the coating being formed in such a way that, if it is used as a component of a contact system, it makes an additional lubrication of the latter unnecessary, and to provide a simple process for producing said electrodeposited coating.
The advantages achieved by the invention are essentially to be perceived in the fact that the coating has a better stability with respect to mechanical stresses. It is a substantial~~ economic advantage that these coatings can be produced in conventional electroplating plants without additional mechanical expenditure.
The further refinements of the invention are subjects of the dependent claims.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying ~1715~5 drawings, which show only one method of implementation and wherein:
Figure 1 shows a partial section through a part having a coating according to the inven~ion, Figure 2 shows a section through a nanoparticle, Figure 3 shows a simplified block diagram of a process according to the invention, and Figure 4 shows a simplified block diagram of a further process according to the invention.
All the elements not required for an immediate understanding of the invention are not shown.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views, Figure 1 shows a partial section, depicted in considerably simplified form, through a part 1 having a coating according to the invention. The part 1 may be of cylindrical design, but it may also have a flat surface which is provided with a coating. The part 1 has a basic material 2 composed of a metal or of a plastic. If the basic material 2 is a plastic matrix, its surface to be coated is metallized before it is introduced into an electroplating bath, for example by chemical deposition of a metal layer on said surface or by vapor deposition of a metal layer under high-vacuum conditions.
Electrodeposited on the basic material 2 is a first metal layer 3 in which homogeneously distributed nanoparticles 4 are incorporated. Said nanoparticles 4 are chemico-physically joined to a substance which reduces the abrasion or the friction. Said substance which reduces the abrasion or the friction is a substance based on surface-active chemical compounds.
Said first metal layer 3 may also be composed of a plurality of consecutively deposited individual layers.
For certain applications, the first metal layer does not need to be coated with further layers. Here, however, the first metal layer 3 is completely coated 2171~85 _ _ 4 _ 95/068 with a metallic top layer 5. The top layer 5 has a smooth surface 6. The metallic top layer 5 has, as a rule, a greater hardness than the first metal layer 3.
For a fixed or comparatively slowly moving component of a silver-plated contact system, it has been found that the first metal layer 3 advantageously has a thickness in the range from 5 ~m to 15 ~m, where-as the metallic top layer 5 has a thickness in the region around 2 ~m. In this connection, the metallic top layer 5 is advantageously formed as a hard silver plating in order to thereby optimize its abrasion behavior.
Depending on the planned field of application of the coating, various, suitably prepared substances can be used as nanoparticles 4, for example carbides such as SiC, WC and TiC, nitrides such as AlN and Si3N4, borides such as TiB, metal oxides such as ZnO, SiO2, Fe2O3, Bi2O3, PdO, NiO, AgO, TeO, CuO, Sb2O3, TiO2, ZrO2, Al2O3, In2O3, SnO, V2O5, TiO2 and MgO and metals such as, for example W and Ni. The nano-particles 4 are produced from the respective basic materials with the aid of one of the known processes.
The nanoparticles 4 have a size in the range from about 5 nm to 50 nm and as a rule, they are spherically formed. The nanoparticles 4 do not have sharp edges.
Nanoparticles 4 composed of a single substance or nanoparticles 4 composed of a mixture of two or more substances are introduced into the electroplating bath.
To achieve a uniform distribution of the nanoparticles 4 in the electroplating bath, the bath is continuously stirred.
If particles are used which have a somewhat coarser structure than the nanoparticles 4 described above, then, although the chemico-physical effective-ness of said particles is somewhat impaired since fewersurface-active chemical compounds may attach themselves to said particles, applications are quite conceivable in which such a coarser structure can advantageously be used. In particular, it is also possible to use ~71585 particles which have a somewhat coarser structure mixed with nanostructured material in order to achieve a specific adaptation to certain specified operating requirements in this way.
As surface-active chemical compounds suitable for attachment to the nanoparticles 4, use may be made of bipolar natural chemical compounds which are referred to as soaps such as, for example, stearates, oleates, palmitates and laureates but synthetic compounds may also be used, such as, for example, sulfonic acids, and in this connection, in particular, toluenesulfonic acid and laurinsulfonic acid, or aminoalcohols, polyalcohols and the like. These compounds attach themselves chemico-physically to the nanoparticles 4, and, as a rule, it is van der Waals' forces which provide for this attachment. The nanoparticles 4 are completely or at least partially enveloped by one of these compounds or by a mixture of two or more of these compounds which reduce the abrasion or the friction.
Figure 2 shows diagrammatically a section through a nanoparticle 4 with its envelope of a surface-active chemical compound attached chemico-physically. The nanoparticle 4 has been produced, for example, from Al2O3, ZrO or TiO2 by one of the known methods. Oxygen O is attached directly to the nanoparticle 4 and a hydrocarbon compoun-d R1 is attached to the oxygen O. Attached here to the hydrocarbon compound R1 is, for example, an amino alcohol NH2 which is to be regarded as the decisive component for the reduction of the abrasion or of the friction when said nanoparticle 4 is incorporated in the first metal layer 3. Additionally, however, hydroxyl groups OH are directly attached to the nanoparticle 4, the hydrogen for said hydroxyl groups being obtained by the attached oxygen O from the water of the electroplating bath. The hydrogen ions of said hydroxyl groups OH are positively charged so that the nanoparticle 4 has, on the whole, a positive electrical - 21715~
~ - 6 - 95/068 charge. The nanoparticles 4 positively charged in this way migrate to the cathode in the electrical field of the electroplating bath, just like the dissolved metals, and are deposited there together with the latter on the part 1 to be coated. In this way, a very homogeneous distribution of the nanoparticles 4 in the first metal layer 3 is achieved without additional aids, which results in a uniform lubricating action by the envelope of the incorporated nanoparticles 4.
The non-oxidic nanoparticles 4 having nitrides, borides, carbides and metals as basic substances are also coated in normal atmosphere with a very thin oxide layer which, after said nanoparticles 4 have been introduced into an electroplating bath, makes possible the same chemico-physical surfaces reactions as those described above in connection with the depiction of the nanoparticle 4 in Figure 2.
Many of these compounds are already used as wetting agents in conventional electroplating baths, but their additional advantageous possible use as means for the reduction of the abrasion or the friction could not be exploited hitherto. It is only as a result of the combination with the nanoparticles 4 which permit an attachment of these compounds in an amount sufficient for a good lubrication by chemico-physical means and which do not themselves have edges which could again destroy the lubricating action thus produced that the advantageous reduction of the abrasion or of the friction is fully realized. The first metal layer 3 is accordingly to be considered as a layer with a self-lubricating action.
Such coatings can advantageously be used as contact surfaces in contact systems. A multiplicity of specific applications of said coatings can be conceived. In a contacting assembly, the coated part 1 may interact as stationary or comparatively slowly moving component with a mobile metallic component which slides or rolls off on said part 1. The part 1 may be formed, for example, as fixed rated-current contact of 7~535 _ 7 _ 95/068 a circuit breaker and a mobile countercontact equipped with silver-plated fingers or silver-plated spiral contacts may be provided as component which slides on said stationary contact. On the one hand, the contact junctions in circuit breakers and in power distribution plants can be improved by these novel silver-plated contacts, and on the other hand, the gold-coated contact areas, for example, in relays can also be made more durable or, given the same service life, be provided with a thinner coating, which results in considerable material savings, given the enormous number of pieces of such contacts.
For use in silver-plated contact zones in metal-enclosed gas-insulated switchgear assemblies filled with SF6 gas, use can be made particularly advantageously of nanoparticles 4 based on carbides and metals and prepared by one of the known processes.
Said nanoparticles 4 have a size of approximately 5 nm to 50 nm. Said nanoparticles 4 are resistant to the decomposition products of the sulfur hexafluoride which is, as a rule, used in said metal-enclosed gas-insulated switchgear assemblies as insulant and as quenching agent for the arc, so that the lubricating capability of the first metal layer 3 is not reduced by said decomposition products. A particularly long service life of the contacts is achieved by the compounds attached to said nanoparticles --4. The abrasion which occurs here comprises comparatively small abrasion particles, and no abrasion particles of critical size occur which could migrate in the electrical field prevailing in the metal-encapsulated gas-insulated high-voltage plants and cause flashovers.
Such coatings can also be advantageously used as surfaces for sliding bearings or other mechaniçally stressed bearings. In a bearing, the part 1 is formed as fixed or comparatively slowly moving component which interacts with a mobile metallic compound which slides or rolls off on said part 1.
- 21~158~
~ - 8 - 95/068 It is also possible to provide consumer products such as, for example, cutlery, jewellery, plastic costume jewellery and the like with the coating according to the invention in order to improve their durability or to save material for the coating. In the case of silver-plated cutlery, the first metal layer 3 is provided, as described, with nanoparticles 4 together with the abrasion-reducing attachments and the top layer 5 on top thereof is a high-polished silver plating.
In the course of time said top layer 5 will chafe through at the most stressed points, so that the first metal layer 3 is laid bare. Due to the doping with the enveloped nanoparticles 4, however, said first metal layer 3 is so abrasion-resistant that the further wear of the cutlery is slowed down considerably, while the visual impression of the cutlery is impaired only slightly.
The process for producing abrasion-resistant electrodeposited layers on parts 1 comprises the following process steps:
a) introduction of nanoparticles into a first electroplating bath, which is continuously stirred, b) introduction of particles which attach themselves to said nanoparticles and which are composed of a substance based on surface-active chemical compounds into the first electroplating bath, c) introduction of a part 1 to be coated into the first electroplating bath, d) performance of an electrolytic coating process until a first, predominantly metallic layer is deposited on the part 1, and e) removal of the part 1 from the electroplating bath.
The part 1 is now coated with the first metal layer 3. Said first metal layer 3 may be built up as a single-layer structure or, alternatively, of a ~ 171~85 plurality of similar layers. In principle, it is also possible to build up said first metal layer 3 from a plurality of layers of various metals, each of said layers being doped, however, with nanoparticles 4. If said first metal layer 3 is used in a bearing, a coating with an additional top layer 5 is not, as a rule, provided. The full effect of the compounds with lubricating action attached to the nanoparticles 4 is thus ensured from the start.
If the coated part 1 is used, for example, for a contact system, the first metal layer 3 is coated with a metallic top layer 5 and the process steps below follow the process steps already listed above:
f~ introduction of the coated part 1 into a second electroplating bath, g) performance of at least one further electrolytic coating process until a second metallic top layer 5 completely covering the first layer is deposited on the part 1, and h) removal of the part 1 coated with two layers from the second electroplating bath.
In most cases, the same metal is dissolved in the first and in the second electroplating bath, but it is also possible, if specific applications require it, for at least two different metals to be dissolved in one or even in both electroplating baths. The hardness of the respective metal layer can thus be adapted by simple means to the respective operating requirements.
Into the first electroplating bath, 0.002 to 0.20 percent by weight of the nanoparticles 4 are introduced. It has been found that an optimum composition of the first metal layer 3 is then obtained. Of the substance based on surface-active chemical compounds, a comparatively small amount, matched to the amount of the nanoparticles 4, is introduced into the first electroplating bath, and in this connection, care is taken that said substance is continuously added. If the amounts of the nanoparticles 4 and of said substance are not matched ~ L 7 .L 5 ~ 5 _ - 10 - 95/068 to one another, an undesirable clotting of the nanoparticles 4 frequently occurs, which has the consequence that these clots settle in the electroplating bath and the homogeneous distribution of the nanoparticles 4 in the first metal layer 3 is then no longer ensured. If attention is paid to the matching of the amounts mentioned, however, the concentration of the electroplating bath is not appreciably affected.
Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.
Claims (18)
1. A part having an electrodeposited coating which is resistant to mechanical abrasion, - wherein homogeneously distributed nano-particles (4) are let into at least one first metal layer (3) of the coating and are chemico-physically joined to at least one substance which reduces the abrasion or the friction.
2. The part as claimed in claim 1 - wherein the at least one first metal layer (3) is completely coated with a metallic top layer (5).
3. The part as claimed in claim 2, - wherein the metallic top layer (5) has a greater hardness than the first metal layer (3).
4. The part as claimed in claim 1, - wherein a substance based on surface-active chemical compounds is chosen as the at least one substance which reduces the abrasion or the friction.
5. The part as claimed in any of the preceding claims, - wherein the part (1) interacts in a contacting or bearing assembly as fixed or comparatively slowly moving component with a mobile metallic component which slides or rolls off on said part.
6. The part as claimed in claim 1, - wherein the nanoparticles (4) have a particle size in the range from 5 nm to 50 nm.
7. The part as claimed in either of claims 2 or 3, - wherein the first metal layer (3) predominantly has silver as metallic matrix, and - wherein the metallic top layer (5) is formed as a hard silver plating.
8. The part as claimed in either of claims 2 or 3, - wherein the first metal layer (3) has a thickness in the range from 5 µm to 15 µm, and - wherein the metallic top layer (5) has a thickness in the region around 2 µm.
9. The part as claimed in either of claims 2 or 3, - wherein the first metal layer (3) and the metallic top layer (5) are composed of different metals or metal alloys.
10. The part as claimed in claim 4, - wherein either bipolar natural chemical compounds which are referred to as soaps or synthetic compounds such as sulfonic acids or aminoalcohols or polyalcohols are used as surface-active chemical compound.
11. The part as claimed in claim 10, - wherein stearates, oleates, palmitates or laureates are used as bipolar natural chemical compounds, and - wherein, in particular, toluenesulfonic acid or laurinsulfonic acid are used as sulfonic acids.
12. The part as claimed in claim 1, - wherein a consumer product is provided as part (1).
13. A process for producing abrasion-resistant electrodeposited layers on parts, which comprises the following process steps:
a) introduction of nanoparticles (4) into a first electroplating bath, which is continuously stirred, b) introduction of particles which attach themselves to said nanoparticles (4) and which are composed of a substance based on surface-active chemical compounds into the first electroplating bath, c) introduction of a part (1) to be coated into the first electroplating bath, d) performance of an electrolytic coating process until a first, predominantly metallic layer (3) is deposited on the part (1), e) removal of the part (1) from the electroplating bath.
a) introduction of nanoparticles (4) into a first electroplating bath, which is continuously stirred, b) introduction of particles which attach themselves to said nanoparticles (4) and which are composed of a substance based on surface-active chemical compounds into the first electroplating bath, c) introduction of a part (1) to be coated into the first electroplating bath, d) performance of an electrolytic coating process until a first, predominantly metallic layer (3) is deposited on the part (1), e) removal of the part (1) from the electroplating bath.
14. The process as claimed in claim 13, - wherein the part (1) is introduced into a second electroplating bath, - wherein a second metallic top layer (5) completely covering the first layer (3) is deposited on the part (1) by means of at least one further electrolytic coating process, and - wherein the part (1) coated with the two layers (3, 5) is then removed from the second electroplating bath.
15. The process as claimed in claim 14, - wherein the same metal is in most cases used in the first and second electroplating baths or at least two different metals are dissolved in at least one of the two baths.
16. The process as claimed in claim 13, - wherein a single chemical substance or a mixture of at least two chemical substances serves as basis for the nanoparticles (4).
17. The process as claimed in claim 16, - wherein some of the chemical substance or some of the mixture is formed from a more coarsely structured material.
18. The process as claimed in claim 13, - wherein 0.002 to 0.20 percent by weight of the nanoparticles (4) are introduced into the first electroplating bath, and - wherein an amount, matched to the amount of the nanoparticles (4), of the substance based on surface-active chemical compounds is introduced into the first electroplating bath.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19521323.8 | 1995-06-12 | ||
| DE1995121323 DE19521323A1 (en) | 1995-06-12 | 1995-06-12 | Part with a galvanically applied coating and method for producing galvanic layers |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2171585A1 true CA2171585A1 (en) | 1996-12-13 |
Family
ID=7764172
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2171585 Abandoned CA2171585A1 (en) | 1995-06-12 | 1996-03-12 | Part having an electrodeposited coating and process for producing electrodeposited layers |
Country Status (6)
| Country | Link |
|---|---|
| EP (1) | EP0748883A1 (en) |
| CN (1) | CN1147569A (en) |
| BR (1) | BR9602735A (en) |
| CA (1) | CA2171585A1 (en) |
| DE (1) | DE19521323A1 (en) |
| PL (1) | PL314668A1 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20100116668A1 (en) * | 2007-04-05 | 2010-05-13 | Freie Universitaet Berlin | Material system and method for producing the same |
| US9780513B2 (en) | 2013-08-16 | 2017-10-03 | Schleifring Und Apparatebau Gmbh | Slip ring assembly and components thereof |
Families Citing this family (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AT408352B (en) * | 1999-03-26 | 2001-11-26 | Miba Gleitlager Ag | GALVANICALLY DEPOSIT ALLOY LAYER, ESPECIALLY A RUNNING LAYER OF A SLIDING BEARING |
| DE10125289B4 (en) * | 2001-05-15 | 2005-04-07 | Siemens Ag | Method for producing an abrasion-resistant, galvanic layer on parts |
| DE10125290B4 (en) * | 2001-05-15 | 2005-04-14 | Siemens Ag | Process for the preparation of nano-dispersants |
| DE10134559B4 (en) * | 2001-07-16 | 2008-10-30 | Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. | Process for coating components, processable dispersible coatings and use |
| DE20206954U1 (en) | 2002-05-02 | 2002-12-05 | Magnetech GmbH, 01877 Bischofswerda | Light cutlery with compact individual parts |
| JP3913118B2 (en) * | 2002-06-13 | 2007-05-09 | 忠正 藤村 | Metal thin film layer in which ultrafine diamond particles are dispersed, metal material having the thin film layer, and methods for producing the same |
| US7297731B2 (en) | 2003-03-11 | 2007-11-20 | 3M Innovative Properties Company | Coating dispersions for optical fibers |
| EP1643016A1 (en) * | 2004-10-04 | 2006-04-05 | Siemens Aktiengesellschaft | Use of surface modified particles in electroplating |
| WO2006099068A1 (en) * | 2005-03-09 | 2006-09-21 | Scarpa Frank C | Liposomal compositions and methods for use |
| EP1707650A1 (en) * | 2005-03-31 | 2006-10-04 | Siemens Aktiengesellschaft | Matrix and coating system |
| DE102005032738B3 (en) * | 2005-07-08 | 2006-11-23 | Siemens Ag | Electrochemical treatment of multiple workpieces comprises connecting units comprising a workpiece and a counterelectrode in series |
| DE102005033857A1 (en) * | 2005-07-12 | 2007-01-18 | Siemens Ag | Electrode assembly and method for electroplating a workpiece surface |
| DE102006045531B3 (en) * | 2006-09-21 | 2008-05-29 | Siemens Ag | Method for producing a layer on a support |
| DE102009014588B4 (en) * | 2009-03-24 | 2013-07-11 | Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. | Metal-based layer system, method for producing the same and use of the layer system or method |
| DE102009036311B4 (en) | 2009-08-06 | 2021-10-28 | Te Connectivity Corporation | Self-lubricating coating, self-lubricating component, coating electrolyte and process for producing a self-lubricating coating |
| CN105624758B (en) * | 2014-11-03 | 2018-07-06 | 宁波瑞隆表面技术有限公司 | A kind of preparation method of cast aluminum alloy micro-arc oxidation ceramic film |
| CN112030213B (en) * | 2020-08-14 | 2021-11-09 | 北京科技大学 | Wear-resistant super-hydrophobic nickel-tungsten/tungsten carbide composite coating and preparation method thereof |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NL125956C (en) * | 1960-07-26 | |||
| FR1420009A (en) * | 1963-12-24 | 1965-12-03 | Kampschulte & Cie Dr W | Method of electrolytically forming corrosion resistant shiny nickel-chromium coating layers |
| US3762882A (en) * | 1971-06-23 | 1973-10-02 | Di Coat Corp | Wear resistant diamond coating and method of application |
| DE2247956C3 (en) * | 1972-09-29 | 1980-11-06 | Toyo Kogyo Co. Ltd., Hiroshima (Japan) | Workpiece with galvanically applied nickel coating and bath for its deposition |
| US3996114A (en) * | 1975-12-17 | 1976-12-07 | John L. Raymond | Electroplating method |
| DE3032469A1 (en) * | 1980-08-28 | 1982-04-01 | Siemens AG, 1000 Berlin und 8000 München | CYANIDIC GOLD BATHS AND GALVANIC DEPOSITION OF SOLID LUBRICANT-CONTAINING GOLD DISPERSION SURFACES AND ITS APPLICATION |
| DE3333121A1 (en) * | 1983-09-14 | 1985-03-28 | AHC-Oberflächentechnik, Friebe & Reininghaus GmbH & Co KG, 5014 Kerpen | Dispersion layers |
| US4910095A (en) * | 1987-12-29 | 1990-03-20 | Nippon Steel Corporation | High corrosion resistant plated composite steel strip |
-
1995
- 1995-06-12 DE DE1995121323 patent/DE19521323A1/en not_active Withdrawn
-
1996
- 1996-03-12 CA CA 2171585 patent/CA2171585A1/en not_active Abandoned
- 1996-05-28 EP EP96810338A patent/EP0748883A1/en not_active Withdrawn
- 1996-06-07 PL PL31466896A patent/PL314668A1/en unknown
- 1996-06-11 BR BR9602735A patent/BR9602735A/en not_active Application Discontinuation
- 1996-06-12 CN CN 96110349 patent/CN1147569A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20100116668A1 (en) * | 2007-04-05 | 2010-05-13 | Freie Universitaet Berlin | Material system and method for producing the same |
| US9780513B2 (en) | 2013-08-16 | 2017-10-03 | Schleifring Und Apparatebau Gmbh | Slip ring assembly and components thereof |
| EP2838166B1 (en) * | 2013-08-16 | 2019-09-25 | Schleifring GmbH | Slip ring assembly and components thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| EP0748883A1 (en) | 1996-12-18 |
| PL314668A1 (en) | 1996-12-23 |
| BR9602735A (en) | 1999-10-13 |
| CN1147569A (en) | 1997-04-16 |
| DE19521323A1 (en) | 1996-12-19 |
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