Electrical contact, contact assembly and switch

Abstract

The utility model belongs to the technical field of switches, and relates to an electric contact, a contact assembly and a switch. The electric contact comprises a conductive base material and n coating layers, n is larger than or equal to 3, the n coating layers sequentially coat the surface of the conductive base material in a stacked mode from the first layer to the nth layer, the first layer is a copper layer, the nth layer is a copper layer or a copper graphene composite layer, the second layer to the (n-1) th layer comprise at least one of a copper graphene composite layer, a nickel graphene composite layer and a copper layer, and n is larger than or equal to 3. The n cladding layers comprise at least one copper-graphene composite layer, at least one nickel-graphene composite layer and at least one copper layer, and the nickel-graphene composite layer is located between the copper layer and the copper-graphene composite layer. The cost of the electric contact piece is reduced, the conductivity and the corrosion resistance are improved, the electric contact piece is applied to the contact assembly and the switch, the electric contact piece can better adapt to scenes with high corrosion, high abrasion resistance and high hardness requirements, the safety of the contact assembly and the switch is improved, and the service life of the contact assembly and the switch is prolonged.

Description

Technical Field

[0001] The present application relates to the field of switch technology, and in particular to an electrical contact, a contact assembly, and a switch. Background Art

[0002] Electrical contacts are common components in electrical products, such as disconnect switches, position detection switches, pushbutton switches, and open-type load switches. These contacts are typically made of copper, which offers excellent electrical conductivity and corrosion resistance. However, copper is expensive. For cost reasons, related technologies often use iron as the conductive substrate, coating it with a zinc-nickel alloy to improve its corrosion resistance.

[0003] However, the electrical conductivity of this iron-based, zinc-nickel alloy-coated electrical contact is mediocre, and its corrosion resistance is not suitable for highly corrosive environments. In such environments, only high-cost, high-purity copper electrical contacts can be used. Therefore, developing a low-cost electrical contact with improved conductivity and corrosion resistance is an important research direction in this field. Utility Model Content

[0004] The present application provides an electrical contact, a contact assembly, and a switch, aiming to reduce costs and improve electrical conductivity and corrosion resistance.

[0005] The embodiment of the present application is implemented as follows:

[0006] In a first aspect, an embodiment of the present application provides an electrical contact, comprising:

[0007] Conductive substrate;

[0008] n coating layers, sequentially stacked from the first layer to the nth layer and coated on the surface of the conductive substrate, wherein: n ≥ 3;

[0009] The first layer is a copper layer, the nth layer is a copper layer or a copper-graphene composite layer, and the second layer to the n-1th layer include at least one of a copper-graphene composite layer, a nickel-graphene composite layer and a copper layer, so that the n cladding layers include at least one copper-graphene composite layer, at least one nickel-graphene composite layer and at least one copper layer, and the nickel-graphene composite layer is located between the copper layer and the copper-graphene composite layer.

[0010] In one embodiment of the present application, the n cladding layers include a copper layer, a copper-graphene composite layer, a nickel-graphene composite layer, and a copper layer stacked in sequence.

[0011] In one embodiment of the present application, the n coating layers include a copper layer, a nickel-graphene composite layer, and a copper-graphene composite layer stacked in sequence.

[0012] In one embodiment of the present application, the copper layer has a thickness of 0.5-1.5 μm.

[0013] In one embodiment of the present application, the copper-graphene composite layer has a thickness of 1-5 μm.

[0014] In one embodiment of the present application, the thickness of the nickel-graphene composite layer is 1-5 μm.

[0015] In one embodiment of the present application, the graphene content in the copper-graphene composite layer is 10-20%.

[0016] In one embodiment of the present application, the graphene content in the nickel-graphene composite layer is 10-20%.

[0017] In a second aspect, an embodiment of the present application provides a contact assembly, comprising the electrical contact described in any one of the first aspects.

[0018] In a third aspect, an embodiment of the present application provides a switch comprising the contact assembly described in the second aspect.

[0019] Beneficial effects:

[0020] The technical solution provided by the embodiment of the present application reduces the amount of nickel, zinc, and copper used compared to the related art, thereby reducing costs. On the basis of cost reduction, on the one hand, the outermost copper layer or copper-graphene composite layer plays a role in preventing corrosion; on the other hand, the middle high-wear-resistant and high-hardness nickel-graphene composite layer improves the hardness and friction resistance of the electrical contact, and utilizes the nickel element therein to change longitudinal corrosion to transverse corrosion when corrosion occurs, thereby making the conductive substrate and the copper layer adjacent to the conductive substrate less susceptible to corrosion, further improving corrosion performance; and the innermost copper layer can further protect the conductive substrate from corrosion. In addition, compared with longitudinal corrosion, transverse corrosion of the nickel-graphene composite layer is easier to be observed by humans, which is conducive to timely replacement of electrical components and avoiding safety accidents. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0022] Figure 1 A cross-sectional view of an electrical contact provided in one embodiment of the present application;

[0023] Figure 2A cross-sectional view of an electrical contact provided in another embodiment of the present application;

[0024] Figure 3 A cross-sectional view of an electrical contact provided in yet another embodiment of the present application.

[0025] icon:

[0026] 100-conductive substrate; 200-cladding layer; Cu-copper layer; Cu / Gr-copper graphene composite layer; Ni / Gr-nickel graphene composite layer. DETAILED DESCRIPTION

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Generally, the components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0028] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for protection, but merely represents selected embodiments of the present application. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments in the present application without creative work are within the scope of protection of the present application.

[0029] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not require further definition or explanation in subsequent drawings.

[0030] In the description of this application, it should be noted that if the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the accompanying drawings, or the orientation or position relationship in which the product of the application is usually placed when in use. It is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, it cannot be understood as a limitation on this application. In addition, if the terms "first", "second", etc. appear in the description of this application, they are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0031] Furthermore, the use of terms such as "horizontal" and "vertical" in the description of this application does not necessarily imply that a component must be absolutely horizontal or suspended, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but rather that it can be slightly tilted.

[0032] It should also be noted that, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood broadly. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. A person of ordinary skill in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0033] The embodiments of the present application provide a technical solution for reducing the production cost of electrical contacts in highly corrosive environments and improving their conductivity.

[0034] In a first aspect, an embodiment of the present application provides an electrical contact, such as Figure 1 As shown, the electrical contact comprises a conductive substrate 100 and n cladding layers 200 , where n≧3.

[0035] In order to reduce costs and improve product quality, the conductive substrate 100 is made of materials such as iron or steel with high strength, high rigidity and relatively low cost. Iron and steel are also easy to process, so that the electrical contacts can be made into different shapes as needed.

[0036] N coating layers 200 are sequentially stacked and coated on the surface of the conductive substrate 100, i.e., from the first layer to the nth layer, they are sequentially stacked and coated on the surface of the conductive substrate 100. Defining the direction closer to the conductive substrate 100 as the inner side and the direction away from the conductive substrate 100 as the outer side, among the n coating layers 200, the first layer is the innermost layer and the nth layer is the outermost layer.

[0037] Among them, the first layer is a copper layer Cu, the nth layer is a copper layer Cu or a copper graphene composite layer Cu / Gr, and the second layer to the n-1th layer include at least one of a copper graphene composite layer Cu / Gr, a nickel graphene composite layer Ni / Gr and a copper layer Cu.

[0038] Thus, the n cladding layers 200 include at least one copper-graphene composite layer Cu / Gr, at least one nickel-graphene composite layer Ni / Gr and at least one copper layer Cu, and the nickel-graphene composite layer Ni / Gr is located between the copper layer Cu and the copper-graphene composite layer Cu / Gr.

[0039] It should be noted that Figure 1In the embodiment, the second layer is exemplarily set as a copper-graphene composite layer Cu / Gr, the n-2 layer is set as a copper layer Cu, and the n-1 layer is set as a nickel-graphene composite layer Ni / Gr. This is only an example for ease of understanding and does not represent a limitation on the second to n-1 layers. In the embodiment of the present application, any layer from the second to n-1 layers can be one of a copper-graphene composite layer Cu / Gr, a nickel-graphene composite layer Ni / Gr, and a copper layer Cu; in addition, Figure 1 The nth layer is exemplarily set as a copper-graphene composite layer Cu / Gr, which does not represent a limitation on the nth layer. In the embodiment of the present application, the nth layer can be set as a copper layer Cu or a copper-graphene composite layer Cu / Gr: as long as "n coating layers 200 include at least one copper-graphene composite layer Cu / Gr, at least one nickel-graphene composite layer Ni / Gr and at least one copper layer Cu, and the nickel-graphene composite layer Ni / Gr is located between the copper layer Cu and the copper-graphene composite layer Cu / Gr".

[0040] In the technical solution provided in the embodiment of the present application, by setting the innermost layer in contact with the conductive substrate as a copper layer Cu, and setting a copper layer Cu or a copper-graphene composite layer Cu / Gr with good corrosion resistance in the outermost layer, a dual anti-corrosion effect is achieved; and by setting a nickel-graphene composite layer Ni / Gr in the middle, since the corrosion potential of copper is higher than that of nickel in the adjacent nickel-graphene composite layer Ni / Gr, when corrosion occurs, the corrosion will change from longitudinal corrosion to lateral corrosion, so that the corrosion is mainly concentrated in the middle nickel-graphene composite layer Ni / Gr, thereby making the conductive substrate 100 and the copper layer Cu adjacent to the conductive substrate 100 less susceptible to corrosion, thereby further improving the corrosion resistance of the entire part; in addition, the innermost copper layer Cu can also improve the bonding strength between the n cladding layers 200 and the conductive substrate 100. In addition, compared with traditional nickel, zinc, copper and other plating layers, the content of highly conductive graphene in the n coating layers 200 set on the surface of the conductive substrate 100 is greatly increased, while the use of nickel, zinc and copper is reduced, the production cost is effectively reduced, and the discharge of heavy metal wastewater is reduced, the production is more environmentally friendly, and the environmental protection cost is also reduced.

[0041] As can be seen from the above, the technical solution provided by the embodiments of the present application reduces the amount of nickel, zinc, and copper used compared to related technologies, thereby reducing costs. Furthermore, on the one hand, the outermost copper layer (Cu) or copper-graphene composite layer (Cu / Gr) acts as a barrier to corrosion. On the other hand, the middle, highly wear-resistant and high-hardness nickel-graphene composite layer (Ni / Gr) further improves the hardness and friction resistance of the electrical contact. Furthermore, the nickel element in the composite layer changes longitudinal corrosion to lateral corrosion when corrosion occurs, thereby making the conductive substrate 100 and the copper layer (Cu) adjacent to the conductive substrate 100 less susceptible to corrosion, further improving corrosion resistance. Furthermore, the innermost copper layer (Cu) further protects the conductive substrate 100 from corrosion. Furthermore, compared to longitudinal corrosion, lateral corrosion of the nickel-graphene composite layer (Ni / Gr) is easier to observe, facilitating timely replacement of the electrical contact and avoiding safety accidents.

[0042] In some embodiments, as Figure 2 As shown, four coating layers 200 are provided on the surface of the conductive substrate 100, that is, n=4. From the innermost layer to the outermost layer, the first layer is a copper layer Cu, the second layer is a copper graphene composite layer Cu / Gr, the third layer is a nickel graphene composite layer Ni / Gr, and the fourth layer is a copper layer Cu. Figure 2 In the embodiment shown, a copper layer Cu, a copper-graphene composite layer Cu / Gr, a nickel-graphene composite layer Ni / Gr, and a copper layer Cu are stacked in sequence: the innermost copper layer Cu improves the bonding strength between the copper-graphene composite layer Cu / Gr and the conductive substrate 100; the copper-graphene composite layer Cu / Gr and the nickel-graphene composite layer Ni / Gr located in the middle are compared with the traditional nickel-plated layer and the copper-plated layer. The copper-graphene composite layer Cu / Gr has better corrosion resistance, and the nickel-graphene composite layer Ni / Gr has better wear resistance and hardness. The combination of the two makes the electrical contact more suitable for In environments with high requirements for hardness and friction resistance and strong corrosion, the outermost copper layer (Cu) can further improve corrosion resistance. Furthermore, because the corrosion potential of copper is higher than that of the nickel in the adjacent nickel-graphene composite layer (Ni / Gr), when corrosion occurs, the corrosion will change from longitudinal corrosion to lateral corrosion, causing the corrosion to be primarily concentrated in the middle nickel-graphene composite layer (Ni / Gr). This makes the conductive substrate 100 and the copper layer (Cu) and copper-graphene composite layer (Cu / Gr) adjacent to the conductive substrate 100 less susceptible to corrosion, further improving the overall corrosion resistance of the part. Furthermore, compared to conventional nickel, zinc, and copper plating, the n coating layers 200 provided on the surface of the conductive substrate 100 contain a significantly increased content of highly conductive graphene, while the amount of nickel, zinc, and copper used is reduced, effectively reducing production costs and reducing the discharge of heavy metal wastewater. This makes production more environmentally friendly and reduces environmental costs.

[0043] In some embodiments, as Figure 3 As shown, three coating layers 200 are provided on the surface of the conductive substrate 100, that is, n=3, from the innermost layer to the outermost layer, the first layer is a copper layer Cu, the second layer is a nickel graphene composite layer Ni / Gr, and the third layer is a copper graphene composite layer Cu / Gr. Figure 3 In the illustrated embodiment, a copper layer (Cu), a nickel-graphene composite layer (Ni / Gr), and a copper-graphene composite layer (Cu / Gr) are sequentially stacked to provide dual corrosion protection for the conductive substrate 100. The nickel-graphene composite layer (Ni / Gr) is located between the copper layer (Cu) and the copper-graphene composite layer (Cu / Gr). Copper has a higher corrosion potential than nickel. When corrosion occurs, it shifts from longitudinal corrosion to lateral corrosion, with the corrosion behavior primarily concentrated in the middle nickel-graphene composite layer (Ni / Gr). This makes the conductive substrate 100 and the copper layer (Cu) and copper-graphene composite layer (Cu / Gr) adjacent to the conductive substrate 100 less susceptible to corrosion, further improving the overall corrosion resistance of the component. Furthermore, the innermost copper layer (Cu) enhances the bonding strength between the nickel-graphene composite layer (Ni / Gr) and the conductive substrate 100, making the overall structure more stable and less susceptible to peeling and damage. In addition, compared with traditional nickel, zinc, and copper plating layers, the content of highly conductive graphene in the n coating layers 200 set on the surface of the conductive substrate 100 is greatly increased, while the use of nickel, zinc, and copper is reduced, the production cost is effectively reduced, and the discharge of heavy metal wastewater is reduced, the production is more environmentally friendly, and the environmental protection cost is also reduced.

[0044] In some embodiments, the copper layer Cu has a thickness of 0.5-1.5 μm.

[0045] In some embodiments, the copper-graphene composite layer Cu / Gr has a thickness of 1-5 μm.

[0046] In some embodiments, the nickel-graphene composite layer Ni / Gr has a thickness of 1-5 μm.

[0047] In some embodiments, the graphene content in the copper-graphene composite layer Cu / Gr is 10-20%.

[0048] In some embodiments, the graphene content in the nickel-graphene composite layer Ni / Gr is 10-20%.

[0049] In a second aspect, an embodiment of the present application provides a contact assembly, the contact assembly comprising the electrical contact member according to any one of the first aspects.

[0050] The contact assembly provided in the embodiment of the present application not only has lower cost, but also has better mechanical properties, better electrical conductivity and longer service life, and is suitable for highly corrosive environments.

[0051] In a third aspect, an embodiment of the present application provides a switch, the switch including the contact assembly in the second aspect.

[0052] The switches referred to in the embodiments of the present application include isolating switches, position detection switches, push button switches, open-type load switches, circuit breakers, etc. The switches provided in the embodiments of the present application have contact assemblies that are low-cost, have good corrosion resistance, and have excellent mechanical properties. The circuit breakers also have high safety in highly corrosive environments.

[0053] The present application will be described in detail below through specific examples. The following examples are only some examples of the present application and are not limitations of the present application.

[0054] Example 1

[0055] This embodiment 1 provides an electrical contact, which includes a conductive substrate made of metallic iron. The exterior of the conductive substrate is plated in sequence to form a 1 μm thick copper layer, a 3 μm thick copper-graphene composite layer, a 3 μm thick nickel-graphene composite layer, and a 1 μm thick copper layer. The copper-graphene composite layer and the nickel-graphene composite layer each contain 15% graphene.

[0056] Example 2

[0057] Example 2 of the present application provides an electrical contact, which includes a conductive substrate made of metallic iron, the exterior of the conductive substrate being plated in sequence to form a 1 μm thick copper layer, a 3 μm thick nickel-graphene composite layer, and a 3 μm thick copper-graphene composite layer, wherein the copper-graphene composite layer and the nickel-graphene composite layer each contain 15% graphene.

[0058] Comparative Example 1

[0059] Comparative Example 1 provides an electrical contact, which includes a conductive substrate made of metallic iron, and an outer portion of the conductive substrate is plated to form a zinc-nickel alloy layer with a thickness of 5 μm.

[0060] The electrical contacts of Example 1, Example 2 and Comparative Example 1 were subjected to salt spray tests, and the test results are summarized in Table 1, where the duration of the salt spray test is the duration for corrosion to diffuse to the surface of the conductive substrate.

[0061]

[0062] From Table 1 we can see that:

[0063] Compared with Comparative Example 1, Examples 1 and 2 exhibited a longer salt spray test duration while maintaining a relatively high electrical conductivity, indicating that the n coating layer structure provided by the embodiments of the present application has better corrosion resistance and electrical conductivity than the zinc-nickel alloy plating in the related art. It can be seen that the technical solution of the embodiments of the present application ensures that the overall structure of the electrical contact is more solid while reducing costs, and the n coating layers are not easy to peel off and damage, and also achieves improved corrosion resistance and electrical conductivity of the electrical contact.

[0064] The above description is merely a preferred embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. An electrical contact, characterized in that: include: Conductive substrate; n coating layers, sequentially stacked from the first layer to the nth layer and coated on the surface of the conductive substrate, wherein: n ≥ 3; The first layer is a copper layer, the nth layer is a copper layer or a copper-graphene composite layer, and the second to n-1th layers include at least one of a copper-graphene composite layer, a nickel-graphene composite layer and a copper layer, so that the n cladding layers include at least one copper-graphene composite layer, at least one nickel-graphene composite layer and at least one copper layer, and the nickel-graphene composite layer is located between the copper layer and the copper-graphene composite layer.

2. The electrical contact according to claim 1, wherein: The n cladding layers include a copper layer, a copper-graphene composite layer, a nickel-graphene composite layer, and a copper layer which are stacked in sequence.

3. The electrical contact according to claim 1, wherein: The n cladding layers include a copper layer, a nickel-graphene composite layer, and a copper-graphene composite layer stacked in sequence.

4. The electrical contact according to claim 1, wherein: The copper layer has a thickness of 0.5-1.5 μm.

5. The electrical contact according to claim 1, wherein: The copper-graphene composite layer has a thickness of 1-5 μm.

6. The electrical contact according to claim 1, wherein: The thickness of the nickel-graphene composite layer is 1-5 μm.

7. A contact assembly, characterized in that: The electrical contact comprises the electrical contact according to any one of claims 1 to 6.

8. A switch, characterized in that: The contact assembly comprises the contact assembly according to claim 7.

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