Contact element having a spray coating, connection assembly, use of a spray medium, and method for manufacturing a contact element

Abstract

To provide a device for electrically connecting electric conductors with each other in a conductive manner, with the lowest possible contact resistance.SOLUTION: A contact element 4 includes a conductive carrier body 10 with at least one contact surface 6, 6a, 6b for contacting at least one electrical conductor 8, 8a, 8b, wherein the at least one contact surface is a contact element having a spray coating 22 made of conductive solid particles 1 distributed over the at least one contact surface. The presence and distribution of the solid particles lead to a reduction in the contact resistance between the contact element and the at least one conductor when the contact element is pressed against the at least one conductor on the at least one contact surface and the solid particles at least partially penetrate into at least one conductor material.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a contact element for contacting at least one electrical conductor such as a bus bar. Furthermore, the present invention relates to an electrical connection assembly comprising such a contact element and at least one electrical conductor. The present invention further relates to the use of a spray coating and a method for manufacturing such a contact element.

Background Art

[0002] In order to transmit current between an electrical module such as a battery module and an electric motor or other power-consuming and power-generating units, electrical conductors formed of copper, aluminum, or their alloys are often used in automotive and energy technologies. For example, it is often necessary to connect electrical conductors in the form of bus bars to each other or to an electrical module in an electrically conductive manner. This is usually done at a specified contact surface that is pressed against each other to establish an electrical connection. This inevitably results in a contact resistance that impairs the transmission of current. The contact resistance consists of a concentrated resistance and a surface contamination resistance.

Summary of the Invention

Problems to be Solved by the Invention

[0003] The present invention is based on the object of providing a device for electrically connecting electrical conductors to each other in an electrically conductive manner with as low a contact resistance as possible.

Means for Solving the Problems

[0004] This object is achieved by a contact element comprising a conductive carrier body having at least one contact surface for contacting at least one electrical conductor, wherein the at least one contact surface has a spray coating formed of conductive solid particles dispersed on the at least one contact surface.

[0005] The features and properties of the solid particles described in the configuration of the present application preferably apply to all solid particles, but at least to most of the solid particles or at least to the average of the solid particles.

[0006] The present invention is advantageous because it can reduce contact resistance, which will be described in more detail below.

[0007] On the other hand, the conductive solid particles can form microcontacts (so-called a-spots) that establish contact at separate locations where current is transmitted between the contact element and at least one electrical conductor. Since these are separate locations, the contact pressure at those locations is higher compared to a continuous contact surface pressed against each other using the same normal force. The possible contamination layer can be broken through, and the surface contamination resistance can be reduced. In addition, the number and position of the separate locations can be optimized by the parameters of the spray coating (for example, particle density).

[0008] On the other hand, when solid particles are dispersed on at least one contact surface, microcontacts (hereinafter also referred to as fine surfaces or fine surfaces establishing contact) are dispersed accordingly. This means that the flow of current is not restricted to a single location and the proportion of the concentrated resistance resulting from the mutual influence of the individual microcontacts can be reduced.

[0009] In short, this means that the presence and dispersion of the solid particles in the contact element according to the present invention reduce the contact resistance.

[0010] The contact element according to the invention may be part of an electrical module, in particular a connection point of the electrical module to which at least one electrical conductor is connected. Alternatively, the contact element according to the invention can be arranged between two electrical conductors connected to each other. In addition, only one side of the contact element according to the invention in such an embodiment can include at least one contact surface having a spray coating according to the invention, and a conventional silver coating can be formed on the other side of the contact element. Furthermore, the two electrical conductors connected to each other can alternatively share at least one contact surface.

[0011] The invention can be further improved by the following embodiments which are advantageous in themselves and can be arbitrarily combined with each other.

[0012] According to an exemplary embodiment, the solid particles can protrude from an oxide layer present in the carrier body and at the same time contact the non-oxidized regions of the carrier body and the contacting conductor.

[0013] According to a further exemplary embodiment, the solid particles can be fixed to the carrier body at one end and protrude from the carrier body at the other end. The oxide layer present in the conductor can be broken open by a locally high contact pressure. The particle size of the solid particles may be larger than the average layer thickness of the oxide layer of the contacting conductor. In order to ensure that the solid particles reach the non-oxidized region of the conductor, the solid particles preferably have a high strength such that the oxide layer present in the contacting conductor is pulverized. If an oxide layer is present, the solid particles can penetrate and span the oxide layer. Thereby, without the need to pretreat or coat at least one electrical conductor to remove the oxide layer or prevent the formation of the oxide layer in the first place, the so-called surface contamination resistance, which is part of the contact resistance, is reduced. Thereby, since a bus bar that has not been processed and coated can be used as an electrical conductor, a great deal of labor and cost can be saved.

[0014] Here, it should be noted that the complexity and cost of the coating have actually decreased, and it is not simply a matter of shifting from an electrical conductor to a contact element. Since the contact element is smaller and easier to handle than an electrical conductor, the coating becomes easier. In addition, the contact element is a widely applicable solution that does not depend on the material of the electrical conductor or the coating. Of course, a coated and pre-treated (e.g., by steel brushing and / or sandblasting) bus bar may be used as the electrical conductor.

[0015] Furthermore, the particle size of the solid particles may be larger than the average surface roughness of at least one contact surface, and in particular may be more than twice as large. The average surface roughness may be, for example, an average roughness value or a roughness depth. It is preferable that the particle size of the solid particles is more than 50 μm. In this way, the solid particles do not sink into the valleys of the surface structure of the contact region, but protrude beyond the tips of the surface structure of the contact surface.

[0016] According to a further possible embodiment of the contact element, the solid particles can have edges, in particular sharp edges, be spattered, and / or be formed into spheres. As a result, the solid particles can adhere sufficiently during the spray coating in order to be fixed to the substrate (i.e., the carrier body). The sharp edges also serve to break through the oxide layer that may be present on the contacting conductor. The solid particles may be spherical, or may be provided in a combination of a spherical shape and a geometry with edges.

[0017] In order to further promote the breaking through of the oxide layer, the solid particles can have a higher hardness than the carrier body. The solid particles can include, for example, at least one material from the group consisting of nickel, silver, platinum, titanium, ruthenium, tungsten, iron, cobalt, zinc, copper, chromium, and magnesium, or alloys thereof. The carrier body can be manufactured, for example, from aluminum, copper, or alloys thereof.

[0018] According to a further possible embodiment of the contact element, the solid particles can comprise a core and a coating. In particular, the solid particles can have a so-called core-shell structure. Since the material of the core is different from the material of the coating, it is possible to provide flexibility in the choice of materials, which is advantageous. For example, the material of the core can be selected with respect to hardness and / or conductivity, and the material of the coating is selected with respect to hardness. The solid particles preferably have a core formed from a copper-zinc or copper-tin alloy or a copper-silver or copper-iron or copper-nickel or copper-magnesium alloy and a coating of nickel, silver, or an alloy thereof.

[0019] According to a further possible embodiment of the contact element, the solid particles can be dispersed over the entire contact surface. Furthermore, the solid particles can be uniformly dispersed on at least one contact surface. In the case of uniformly dispersed solid particles, the average number of solid particles per unit area (i.e., the particle density) is constant for different regions, or at least has a deviation within ±20%, particularly within ±10%. In this way, the available space is used as completely as possible.

[0020] However, the solid particles do not need to cover the entire contact surface. According to an embodiment that saves on the material and cost of the contact element, it is sufficient if the solid particles cover less than 10% of the surface of at least one contact surface.

[0021] In order to maintain the correction of the concentration resistance as large as possible, the individual solid particles can be spaced apart from each other. In other words, the solid particles form no agglomerates, or at least hardly any agglomerates, as much as possible. Alternatively, the solid particles can of course form agglomerates. In order to achieve a favorable current distribution, the agglomerates can be spaced apart from each other.

[0022] In addition, the solid particles can be dispersed aperiodically (i.e., not periodically or not forming a regular pattern) on at least one contact surface. This embodiment has the advantage that when the contact element and at least one conductor are repeatedly connected as part of repair and maintenance work, the coatings (impressions) formed by the solid particles on at least one conductor do not fall on top of each other. As expected for periodic dispersion, if the coatings fall on top of each other, the coatings become wear regions, thus impairing current transmission. In other words, due to the aperiodic dispersion of the solid particles, when the contact element is reconnected to at least one conductor, there is a higher likelihood of new coatings forming at locations that have not yet worn, compared to periodic dispersion. Alternatively, the solid particles and aggregates of solid particles may, of course, be dispersed periodically (i.e., forming a regular pattern) on at least one contact surface.

[0023] According to a further possible embodiment, the spray coating can include a material having an affinity for oxygen, such as chromium or magnesium. The material having an affinity for oxygen can be dispersed throughout the contact surface or limited to the edge region of at least one contact surface. Further, the material having an affinity for oxygen may be present as another powder component mixed with the solid particles. The material having an affinity for oxygen can be a substance having a low electrochemical standard potential, particularly lower than that of the solid particles, the contact element, and / or at least one conductor. Thereby, the material having an affinity for oxygen can function as a deoxidizer (so-called getter) and can prevent or at least reduce the occurrence of oxidation in the microcontact.

[0024] The carrier body can optionally include two contact surfaces that face in opposite directions for contacting one electrical conductor each. Both contact surfaces can have a spray coating. Thus, a contact element can be arranged particularly easily between two electrical conductors connected to each other. Thereafter, current flows from one of the two conductors, through the solid particles of the first contacting contact surface, through the carrier body, and into the other of the two conductors through the solid particles of the second contact surface.

[0025] In particular, the carrier body can be configured as a disc-shaped flat body having two flat surfaces that preferably extend parallel to each other and are arranged opposite to each other. These flat surfaces each form a contact surface. Furthermore, the flat surfaces each have a spray coating. Due to the disc-shaped configuration, the contact element can be used, for example, as part of a retrofit component for the conductive connection of two existing busbars that were previously directly connected to each other without occupying an excessive installation space.

[0026] The initially stated object can also be achieved by a connection assembly comprising a contact element according to one of the foregoing embodiments and at least one electrical conductor, wherein the contact element is pressed against the at least one conductor and the solid particles of the spray coating penetrate at least partially into or are pressed into the material of the at least one conductor. The at least one electrical conductor can be manufactured from copper, aluminum, or an alloy thereof. The solid particles of the spray coating are present on at least one side of the contact element, preferably on the side that is pressed against the contacting conductor.

[0027] The connection assembly is effective due to the advantages and technical effects of the contact element according to the present invention described above. In particular, the solid particles of the spray coating form a fine surface (i.e., an a-spot) that establishes the contact described above at the location where the solid particles penetrate or are pressed into the material of at least one conductor. Thus, the connection between the contact element and at least one electrical conductor is characterized by a low contact resistance.

[0028] The connection assembly optionally comprises a mounting device, which is configured to press the contact element against at least one electrical conductor during press-fitting.

[0029] The mounting device can be, for example, a screw and nut or a threaded sleeve or a rivet, respectively. In this case, the contact element can include an opening for the mounting device, in particular a central opening, which extends through the carrier body. In the case of a disc-shaped carrier body, the opening can extend perpendicular to two flat surfaces. For example, a washer or a spacer sleeve can be used as the carrier body, and the washer or spacer sleeve is formed from copper, aluminum, or an alloy based on one of these metals.

[0030] Alternatively, the mounting device can be configured as a clip or a clamp. Thus, the carrier body does not necessarily require an opening. If necessary, the connection assembly can comprise several mounting devices, in particular to form a particularly high composite press-fit.

[0031] According to a possible embodiment of the connection assembly, the solid particles of the spray coating can have a high strength such that the oxide layer present on at least one conductor is crushed. In particular, the solid particles of the spray coating can have a higher elongation at break than the oxide layer present on at least one conductor. In other words, the oxide layer is more brittle or ductile than the solid particles, and thus, when the contact element and at least one electrical conductor are pressed against each other, the solid particles break through the oxide layer. In particular, the solid particles protrude through the oxide layer of at least one electrical conductor and extend to the non-oxidized region of at least one electrical conductor.

[0032] Applying and / or introducing the solid particles to one of the conductor or the carrier material respectively can be achieved using various spray coating processes.

[0033] The connection assembly optionally comprises two electrical conductors. If there is one or more mounting devices, the mounting devices can hold a contact element between the two electrical conductors.

[0034] A first use of a spray medium or spray comprising a carrier gas and conductive solid particles for forming a spray coating on the conductive carrier body of the contact element also achieves the first-mentioned object. In particular, this use enables a simple manufacture of the contact element according to the invention having the advantages and technical effects described above.

[0035] A second use of the conductive solid particles applied to the conductive carrier body of the contact element by a spray coating for penetrating one or more oxide layers when the contact element is brought into contact with at least one electrical conductor also achieves the first-mentioned object since the contact resistance can be reduced by the solid particles.

[0036] A third use of the contact element with a carrier body for the conductive connection of two electrical conductors likewise achieves the initially stated object, where two flat surfaces of the carrier body are each arranged on one of the two conductors, the contact element is pressed between the two conductors, and the solid particles of the spray coating in the carrier body penetrate at least partially into the material of each conductor. In this third use, the contact element has the advantages and technical effects described above.

[0037] The method for manufacturing the contact element according to the invention likewise achieves the initially stated object, the method comprising the steps of providing at least one contact surface on the conductive carrier body and spraying conductive solid particles onto at least one contact surface. In the spraying process, the spray coating described above is applied to at least one contact surface. Subsequently, the formed contact element can be used as described above, bringing about its advantages and technical effects.

[0038] According to a possible embodiment of the method, scattered, spherical, and / or edged powder can be used as the starting material for the conductive solid particles. Thus, the solid particles can be present in the spray medium as scattered, spherical, and / or edged powder when first used according to the invention. The scattered, spherical, and / or edged structure enables such powder particles to be sufficiently fixed to the carrier body. Additionally, such powder particles are advantageous because they can easily break through the oxide layer. Powders having a spherical, cracked, ellipsoidal, or block-shaped particle shape may also be used.

[0039] According to an embodiment of the contact element that is easy to manufacture, the spray coating may be a thermal spray coating, particularly a cold gas spray coating or a plasma spray coating. In the method according to the invention, the spray process can be suitably carried out using the cold gas spraying method or the plasma spraying method. This has the additional advantage that combinations of materials that cannot be welded or coated can also be implemented with the contact element.

[0040] In order to maintain the structure of the solid particles, particularly a structure with edges, sharp edges, or a scattered structure, or at least to minimize changes in the structure of the solid particles and significantly prevent oxidation of the particles, the solid particles should not melt or fuse during the spray process as much as possible. In particular, the conductive solid particles can be applied by accelerating them mainly in the direction of at least one contact surface. For example, the cold gas spraying method or the plasma spraying method exposed to an inert / oxygen-free atmosphere can be used.

[0041] Hereinafter, with reference to the drawings, the present invention will be described in more detail based on some exemplary embodiments. Different features of the exemplary embodiments can be combined with each other as needed according to the above views. In particular, if the effects of individual features are required for a specific application, these features can be added to the described embodiments according to the above description. Conversely, if the technical effects of individual features are not important in a specific application, these features can be omitted from the existing embodiments. Similarly, in the drawings, identical, and functionally identical elements are denoted by the same reference numerals as appropriate.

Brief Description of the Drawings

[0042]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

[0043] Hereinafter, with reference to the exemplary embodiment of FIG. 1, the schematic structure of the contact element 4 according to the present invention will be described. Further, with reference to FIG. 2, the method according to the present invention will be described. In addition, with reference to FIGS. 3 to 5, the schematic structure of the connection assembly 2 according to the present invention will be described. Finally, with reference to FIGS. 2 to 4, the first, second, and third uses according to the present invention will be briefly described. Note that FIGS. 1 to 5 are highly simplified schematic diagrams and should not be understood to be to scale in particular.

[0044] It can be seen from FIG. 1 that the contact element 4 comprises a conductive carrier body 10 having at least one contact surface 6 for contacting at least one electrical conductor 8. The carrier body 10 can optionally include two contact surfaces 6a, 6b that face in opposite directions for contacting one electrical conductor 8 each (see FIG. 4). In particular, the carrier body 10 can be configured in a disc shape having two flat surfaces 12 that preferably extend parallel to each other and are arranged opposite to each other. These flat surfaces 12 each form one of the contact surfaces 6a, 6b.

[0045] Furthermore, the contact element 4 can include an opening 14, in particular a central opening 16, which extends through the carrier body 10 perpendicular to the two flat surfaces 12. For example, a washer 18 or a spacer sleeve (not shown) can be used as the carrier body 10. A screw 20 can be inserted into the opening 14 (see FIG. 4).

[0046] At least one contact surface 6 has a spray coating 22 formed from conductive solid particles 1 dispersed on the at least one contact surface 6. In particular, both contact surfaces 6a, 6b can have the spray coating 22.

[0047] The solid particles 1 can form fine surfaces (so-called a-spots) that establish contact at separate locations 24 where current is transmitted between the contact element 4 and at least one electrical conductor 8. Furthermore, by dispersing the solid particles 1 on at least one contact surface 6, the fine surfaces that establish contact are also dispersed accordingly.

[0048] The features and properties of the solid particles 1 described in the configuration of this application preferably apply to all solid particles 1, but at least to most of the solid particles 1 or at least to the average of the solid particles 1.

[0049] As can be seen from the detailed view 26 of FIG. 1, the individual solid particles 1 are spaced apart from each other. In other words, the solid particles 1 form no aggregates, or at least hardly any aggregates, as much as possible. In addition, the solid particles 1 are dispersed non-periodically (i.e., not periodically or not forming a regular pattern) on at least one contact surface 6. Alternatively, the solid particles 1 may of course be dispersed periodically (i.e., forming a regular pattern) and / or as aggregates on at least one contact surface 6.

[0050] The solid particles 1 can be dispersed throughout the contact surface 6. However, the solid particles 1 do not necessarily have to cover the entire contact surface 6, and it is sufficient if they cover less than 10% of the surface of at least one contact surface 6. Furthermore, the solid particles 1 can be uniformly dispersed on at least one contact surface 6. That is, the average number of solid particles 1 per unit area is constant for different regions, or at least has a deviation within ±20%, particularly within ±10%.

[0051] As schematically shown in FIG. 3, the solid particle 1 can protrude from the oxide layer 28 present in the carrier body 10 at one end and at the same time can contact the non-oxidized region 30 of the carrier body 10 at the other end. In other words, the particle size of the solid particle 1 may be larger than the average layer thickness of the oxide layer 28 of the carrier body 10. In particular, the solid particle 1 may reach the non-oxidized region 30 of the carrier body 10 and be fixed thereto. To achieve this, it is preferable that the solid particle 1 has higher toughness, particularly higher elongation at break, than the oxide layer 28 of the carrier body 10. Thereby, the solid particle 1 can penetrate through and span across the oxide layer 28 of the carrier body 10.

[0052] As can be seen from FIGS. 2 and 3, the particle size of the solid particle 1 is larger than the average surface roughness of at least one contact surface 6, and in particular may be more than twice as large. The average surface roughness may be, for example, an average roughness value or a roughness depth. It is preferable that the particle size of the solid particle 1 exceeds 50 μm. Accordingly, the solid particle 1 does not sink into the valleys 32 of the surface structure of the contact surface 6 and at the same time protrudes beyond the tips 34 of the surface structure of the contact surface 6 (see FIG. 3).

[0053] As schematically shown in FIGS. 2 to 4, the solid particle 1 can be configured to have an edge, particularly a sharp edge. As a result, the solid particle 1 can adhere sufficiently to be fixed to the substrate (i.e., the carrier body 10) (see FIG. 3).

[0054] To further promote the fixation of the solid particle 1, the solid particle 1 can have a higher hardness than the carrier body 10. The respective hardnesses of the solid particle 1 and the carrier body 10 may be, for example, hardness according to martensite hardness, Vickers hardness, Shore hardness, Brinell hardness, or Rockwell hardness, or another hardness scale. The solid particle 1 can include, for example, at least one material from the group consisting of nickel, silver, platinum, ruthenium, tungsten, iron, cobalt, zinc, copper, and magnesium, or alloys thereof. The strength of the solid particle 1, particularly the tensile strength and / or compressive strength, is 500 N / m2 Preferably, it is excellent. The carrier body 10 can be manufactured from, for example, aluminum, copper, or alloys thereof.

[0055] As schematically shown in FIG. 2, the solid particles 1 can include a core 36 and a coating 38. In particular, the solid particles 1 can have a so-called core-shell structure. Here, since the material of the core 36 is different from the material of the coating 38, it can provide flexibility in material selection, which is advantageous. For example, the material of the core 36 can be selected with respect to hardness, and the material of the coating 38 is selected with respect to conductivity. The solid particles 1 preferably have a core 36 formed from a copper-zinc alloy or a copper-magnesium alloy and a coating 38 formed from nickel, silver, or alloys thereof.

[0056] The spray coating 22 can include a material (not shown) having an affinity for oxygen, such as chromium and / or magnesium. The material having an affinity for oxygen can be dispersed throughout the contact surface 6 or limited to the edge region of at least one contact surface 6. Further, the material having an affinity for oxygen may be present as another powder component mixed with the solid particles 1 in the core 36 of the solid particles 1 and / or the coating 38 of the solid particles 1. The material having an affinity for oxygen can be a substance having a low electrochemical standard potential, particularly lower than that of the solid particles 1, the contact element 4, and / or at least one conductor 8. Thereby, the material having an affinity for oxygen can function as a deoxidizer and prevent or at least reduce the occurrence of oxidation in the microcontacts establishing contact.

[0057] The connection assembly 2 shown in FIG. 4 can comprise a contact element 4 and at least one conductor 8. The contact element 4 is pressed against at least one conductor 8, and the solid particles 1 of the spray coating 22 penetrate at least partially into or are pressed into the material of at least one conductor 8. At least one electrical conductor 8 can be configured as a busbar and manufactured from copper, aluminum, or a conductive alloy.

[0058] In particular, the connection assembly 2 can comprise two electrical conductors 8a, 8b connected to each other, for example two busbars. As can be seen from FIG. 4, the contact element 4 is then arranged between the two electrical conductors 8a, 8b and can function as a contact bridge 40. The current flow here (indicated by the dashed line 61 representing some current paths) occurs from one of the two conductors, 8a, through the solid particles 1 of the first contact surface 6a, through the carrier body 10, through the solid particles 1 of the second contact surface 6b, and into the other of the two conductors, 8b, or vice versa. According to an alternative embodiment, the first contact surface 6a has a spray coating containing solid particles, and the second contact surface 6b has a conventional silver coating (see the enlarged view of FIG. 5). If necessary, the contact element 4 can be welded or soldered to the second contact surface 6b of the conductor 8a.

[0059] According to an alternative embodiment (not shown), two electrical conductors connected to each other can share a contact surface. In other words, the two electrical conductors can be placed adjacent to each other on the same contact surface. Furthermore, the contact element can instead be a part of an electrical module (not shown), in particular a connection point of an electrical module to which at least one electrical conductor is connected.

[0060] The connection assembly 2 can comprise a mounting device 42, which is configured to press the contact element 4 against at least one electrical conductor 8 during press-fitting. Thus, the contact element 4 is pressed against at least one conductor 8 by the mounting device 42 during press-fitting. The mounting device 42 can be, for example, the screw 20 and nut 44 described above or a threaded sleeve (not shown) or a rivet. In the embodiment shown in FIG. 4, the mounting device 42 can hold the contact element 4 between two electrical conductors 8a, 8b.

[0061] According to an embodiment not shown, the mounting device 42 can be configured as a clip or a clamp. Thereby, the carrier body 10 does not necessarily require an opening 14. If necessary, the connection assembly 2 can comprise several mounting devices 42.

[0062] The solid particles 1 of the spray coating 22 can have a higher toughness or strength, in particular a higher elongation at break, than the oxide layer 46 present on at least one conductor 8. In other words, the oxide layer is more brittle or ductile than the solid particles 1, so that when the contact element 4 and at least one electrical conductor 8 are pressed against each other, the solid particles 1 break through the oxide layer 46. In particular, the solid particles 1 protrude through the oxide layer 46 of at least one electrical conductor 8 and extend to the non-oxidized region 48 of at least one electrical conductor 8 (see FIG. 4).

[0063] The method according to the invention is used for manufacturing the contact element 4 according to the invention and comprises, as method steps, providing at least one contact surface 6 on the conductive carrier body 10. As shown in FIG. 3, this is followed by the further method step of spraying conductive solid particles 1 onto at least one contact surface 6.

[0064] In the spraying process, a spray coating 22 is applied to at least one contact surface 6. The spray coating 22 may be a spray coating 50, in particular a thermal spray coating 52. Thus, the spraying process can be carried out using a thermal spraying process, such as cold gas spraying or plasma spraying. Depending on the spraying process used, the thermal spray coating may be a cold gas coating or a plasma spray coating.

[0065] Scattered, edged, and / or spherical powder 56 can be used as the starting material 54 of the conductive solid particles 1. Powders having a cracked, spherical, or block-shaped particle shape may be used instead.

[0066] In order to maintain the structure of the solid particles 1, in particular a scattered structure with edges or sharp edges, or to minimize the change in the structure of the solid particles 1 as much as possible, the solid particles 1 do not melt or fuse during the spraying process, or melt as little as possible. In particular, the solid particles 1 can be applied by accelerating them mainly in the direction of at least one contact surface 6. This is shown by arrow 58 in FIG. 2. For example, the cold gas spraying method can be used.

[0067] FIG. 2 shows a first use according to the invention of a spray medium 60, a spraying agent, or a spray containing conductive solid particles 1 for forming a spray coating 22 on the conductive carrier body 10 of the contact element 4.

[0068] FIG. 4 shows a second use according to the invention of conductive solid particles 1 applied to the conductive carrier body 10 of the contact element 4 by a spray coating for penetrating the oxide layers 28, 46 when the contact element 4 is brought into contact with at least one electrical conductor 8.

[0069] Figure 4 similarly shows a third use according to the invention of a contact element 4 with a carrier body 10 for the conductive connection of two electrical conductors 8a, 8b. Two flat surfaces 12 of the carrier body 10 are each applied to one of the two conductors 8a, 8b, the contact element 4 is pressed between the two conductors 8a, 8b, and the solid particles 1 of the spray coating 22 in the carrier body 10 penetrate at least partially into the material of each conductor 8a, 8b.

Explanation of Signs

[0070] 1 Solid particles 2 Connection assembly 4 Contact element 6, 6a, 6b Contact surfaces 8, 8a, 8b Conductors 10 Carrier body 12 Flat surfaces 14 Opening 16 Central opening 18 Washer 20 Screw 22 Spray coating 24 Separate locations 26 Detail drawing 28 Oxide layer 30 Region 32 Valley 34 Tip 36 Core 38 Coating 40 Contact bridge 42 Mounting device 44 Nut 46 Oxide layer 48 Region 50 Spray coating 52 Sprayed coating 54 Starting material 56 Scattered powder 58 Arrow 60 Spray medium 61 Line

Claims

1. A connection assembly (2) comprising a contact element (4) and at least one electrical conductor (8, 8a, 8b), wherein the contact element (4) comprises a conductive carrier body (10) having at least one contact surface (6, 6a, 6b) for contacting the at least one electrical conductor (8, 8a, 8b), the at least one contact surface (6, 6a, 6b) having a spray coating (22) formed from conductive solid particles (1) dispersed on the at least one contact surface (6, 6a, 6b), the carrier body (10) comprising a non-oxidized region (30) and an oxide layer (28) covering the non-oxidized region (30), the at least one electrical conductor (8, 8a, 8b) comprising a non-oxidized region (48) and an oxide layer (46) covering the non-oxidized region (48), and the solid particles (1) penetrating through the oxide layer (28) of the carrier body (10) and the oxide layer (46) of the at least one electrical conductor (8, 8a, 8b) to contact the non-oxidized region (30) of the carrier body (10) and the non-oxidized region (48) of the at least one electrical conductor (8, 8a, 8b).

2. The connection assembly (2) according to claim 1, wherein one end of the solid particle (1) penetrates through the oxide layer (28) of the carrier body (10) and the oxide layer (46) of the at least one electrical conductor (8, 8a, 8b) to contact the non-oxidized region (48) of the at least one electrical conductor (8, 8a, 8b), and the other end different from the one end contacts the non-oxidized region (30) of the carrier body (10).

3. The connection assembly (2) according to claim 1, wherein the average particle size of the solid particles (1) is larger than the average surface roughness of the at least one contact surface (6, 6a, 6b) and the average layer thickness of the oxide layer (28) of the carrier body (10).

4. The connection assembly (2) according to claim 1, wherein the solid particles (1) have edges and / or are configured in a spherical shape.

5. The connection assembly (2) according to claim 1, wherein the solid particles (1) have a higher hardness than the carrier body (10).

6. The connection assembly (2) according to claim 1, wherein the solid particles (1) comprise a core (36) and a coating (38).

7. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The solid particles (1) are uniformly or non-periodically dispersed on the at least one contact surface (6, 6a, 6b) and / or cover less than 10% of the surface of the at least one contact surface (6, 6a, 6b), the connecting assembly (2) according to claim 1.

8. The spray coating (22) contains chromium and / or magnesium, which are materials having an affinity for oxygen, the connecting assembly (2) according to claim 1.

9. The carrier body (10) includes two contact surfaces (6, 6a, 6b) facing in opposite directions for contacting one electrical conductor (8, 8a, 8b) respectively, the connecting assembly (2) according to claim 1.

10. The contact element (4) is pressed against the at least one electrical conductor (8, 8a, 8b), the connecting assembly (2) according to claim 1.

11. The solid particles (1) of the spray coating (22) have a high strength such that they penetrate the oxide layer (46) of the at least one electrical conductor (8, 8a, 8b), the connecting assembly (2) according to claim 1.

12. Use of a spray medium (60) containing a carrier gas and the solid particles (1) for forming the spray coating (22) on the conductive carrier body (10) of the contact element (4) according to claim 1.

13. A method for manufacturing the contact element (4) according to claim 1, - a step of providing the at least one contact surface (6, 6a, 6b) on the conductive carrier body (10); - a step of spraying the conductive solid particles (1) onto the at least one contact surface (6, 6a, 6b); a step of forming the spray coating (20) containing the solid particles (1) on the at least one contact surface (6, 6a, 6b); The method comprising.

14. A method according to claim 13, wherein powder (56) having edges and / or being spherical is used as the starting material (54) of the solid particles (1).

15. The spray process is carried out using a cold gas spray method or a plasma spraying method, the method according to claim 13.

16. The solid particles are composed of one or more of Ti, W, Ru, Cr, Zn, Fe, Ag, Co, Pt, Ni, Mg, or Cu alloys. The method according to any one of claims 13 to 15.

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