Ultralight high-conductivity alloy terminal

Abstract

The invention relates to the technical field of connector terminals, in particular to an ultralight high-conductivity alloy terminal, which solves the problem of electrochemical corrosion when an aluminum or aluminum alloy terminal is connected with a copper or copper alloy conductor in the prior art, and comprises a terminal head part and a terminal tail part which are made of an aluminum alloy material, nickel layers are attached to the surfaces of the terminal head and the terminal tail, and tin layers or indium layers are attached to the surfaces of the nickel layers; the terminal tail part comprises a conductor crimping part, and a carbon coating layer is attached to the surface of a tin layer or an indium layer in a crimping area of the conductor crimping part. The beneficial effects of the invention are that the terminal is made of an aluminum alloy base material through stamping and bending, the product structure is reliable and stable, and the weight is light; the carbon coating layer attached to the surface of the tail part of the terminal can prevent electrochemical corrosion between the aluminum terminal and the copper wire. A nickel layer is attached to the surface of the terminal and is used for increasing the adhesive force of the tin layer or the indium layer; the tin layer or the indium layer increases the oxidation resistance of the adhesion layer and prevents the oxidation reaction on the surface of the terminal; and stable and reliable electric contact can be provided.

Description

Technical Field

[0001] This invention relates to the field of connector terminal technology, and in particular to an ultralight, high-conductivity alloy terminal. Background Technology

[0002] With the increasing demands for lightweight automotive bodies, automotive electrical connection terminals are also developing towards miniaturization and weight reduction. For example, patent CN102439796A discloses a connector terminal, which includes: an electrical contact portion that makes contact and conducts electricity with a mating connector terminal by fitting into the mating terminal; and a conductor crimp portion that crimps onto the conductor of an electrical wire. The metal material constituting the connector terminal uses aluminum or aluminum alloy as the base material, effectively reducing the terminal weight. However, this patent does not solve the key technical problem of connecting the aluminum or aluminum alloy base material with a copper or copper alloy conductor.

[0003] In the field of electrical connections, when aluminum or aluminum alloy terminals are directly connected to copper or copper alloy conductors, the significant difference in the standard electrode potentials of the two metals makes them highly susceptible to galvanic corrosion under the influence of electrolytes in the automotive operating environment. This galvanic corrosion causes preferential oxidation of the aluminum substrate, generating porous corrosion products at the interface and compromising the integrity of the electrical contact interface. The insulating properties of the corrosion products significantly increase contact resistance and can even lead to safety hazards such as localized overheating and melting.

[0004] In existing technologies, the following measures are mainly taken to address the corrosion problem of copper-aluminum connections: Surface plating treatment: such as plating nickel or tin on the surface of copper terminals to isolate the two metals from contact, but the plating thickness is difficult to control, and the plating is prone to cracking and peeling after long-term use, which accelerates corrosion. Sealing and isolation technology: Resin potting or double-wall heat shrink tubing is used to seal the crimped area, but the process is complex and costly, and it cannot completely prevent electrolyte from seeping in due to tiny gaps; Transition layer design: such as the copper-aluminum transition terminal disclosed in patent CN117543231A, which increases the contact area by combining crimping and welding, but the welding process poses a challenge to the structural stability of miniaturized terminals and does not fundamentally solve the potential difference problem.

[0005] These methods all have limitations in practical applications: plating processes struggle to ensure coating uniformity after terminal miniaturization; sealing technologies increase manufacturing steps and material costs; and transition layer design introduces new interfacial bonding strength issues. Furthermore, with the miniaturization of terminal specifications, current density increases significantly, further exacerbating the electrochemical corrosion rate.

[0006] Therefore, how to effectively solve the electrochemical corrosion problem when connecting aluminum or aluminum alloys with copper or copper alloys while meeting the requirements of lightweighting has become a key bottleneck restricting the development of automotive electrical connection technology. Summary of the Invention

[0007] This invention proposes an ultralight, high-conductivity alloy terminal, which solves the problem of electrochemical corrosion when aluminum or aluminum alloy terminals are connected to copper or copper alloy conductors in the prior art.

[0008] The technical solution of this invention is implemented as follows: An ultralight, high-conductivity alloy terminal includes a terminal head and a terminal tail made of aluminum alloy. Both the terminal head and tail are coated with a nickel layer, and a tin or indium layer is coated on the surface of the nickel layer. The terminal tail includes a conductor crimping portion, and a carbon coating is coated on the surface of the tin or indium layer in the crimping area of ​​the conductor crimping portion. Using aluminum alloy as the substrate ensures both lightweight construction and enhanced terminal strength through material alloying, guaranteeing the structural reliability of the miniaturized terminal while maintaining its light weight. The terminal head employs a composite plating layer, with the nickel layer serving as a transition layer. This layer isolates the aluminum substrate from the outer metal, preventing aluminum oxidation and diffusion, and enhances the adhesion of the tin or indium layer through lattice matching, providing stable and reliable electrical contact. The carbon coating layer isolates the aluminum terminal from direct contact with the copper conductor, eliminating potential differences and preventing electrochemical corrosion between the terminal material and the conductor material.

[0009] The conductor crimping portion has a U-shaped structure with serrated recesses on the inner side. A carbon coating layer is attached to the surface of these recesses. This ensures that the carbon coating layer completely covers the crimping area of ​​the conductor crimping portion, effectively isolating direct contact between the aluminum terminal and the copper wire. When the conductor crimping portion crimps the conductor, the serrated recesses mechanically remove the oxide layer on the conductor surface, allowing the carbon coating layer to directly contact the conductor surface. This, in turn, creates a stable electrical contact between the conductor crimping portion and the conductor, ensuring a stable conductive path.

[0010] The serrated recess is an elongated structure, arranged perpendicular to the terminal axis. The depth of the serrated recess is 0.1~0.3mm.

[0011] The carbon coating layer has a carbon content of 1.3~1.5 g / m². 2 Specifically, the carbon coating amount is selected to be 1.3 g / m². 2 The carbon coating can prevent electrochemical corrosion at the contact point between the aluminum terminal and the copper wire, and increase the conductivity of the interface.

[0012] The nickel layer attached to the surface of the terminal head has a thickness of 2.1~3μm. The nickel layer acts as a transition layer, effectively increasing the adhesion of the tin or indium layer to the terminal.

[0013] The thickness of the indium layer attached to the nickel layer surface is 1.5~5μm. A thicker indium layer can increase the oxidation resistance of the attached layer and reduce the oxidation of the aluminum surface.

[0014] The thickness of the tin layer attached to the nickel layer surface is 2~5μm. A thicker tin layer can increase the oxidation resistance of the attached layer and reduce the oxidation of the aluminum surface.

[0015] The terminal also includes an insulating crimping portion at its tail, which has a cross-U-shaped structure. When the terminal is crimped to a wire, the insulating crimping portion is tightly pressed against the wire insulation. The cross-U-shaped structure increases the area covered by the wire insulation, improving connection reliability under vibration conditions.

[0016] The terminal head, conductor crimping portion, and insulation crimping portion are integrally connected. The terminal head, conductor crimping portion, and insulation crimping portion are made of aluminum alloy substrate through stamping and bending. This simple manufacturing process facilitates the miniaturized mass production of the terminals.

[0017] The terminal is either a socket terminal or a plug terminal. Socket terminals and plug terminals are interlocked, and both socket terminals and plug terminals include a terminal head and a terminal tail.

[0018] The beneficial effects of this invention are: 1. The terminals are made of aluminum alloy substrate by stamping and bending, which not only ensures the lightweight of the terminals but also improves the strength of the terminals through material alloying, ensuring the structural reliability and stability of the miniaturized terminals and the light weight of the products.

[0019] 2. The terminal tail can be crimped with copper or copper alloy conductors; the carbon coating layer attached to the surface of the terminal tail can isolate the direct contact between the aluminum terminal and the copper wire, eliminate potential difference, reduce the resistance change rate between the aluminum terminal and the copper wire, and avoid electrochemical corrosion between the terminal material and the conductor material.

[0020] 3. A nickel layer is attached to the terminal surface. The nickel layer serves as a transition layer, which enhances the adhesion of the tin or indium layer. The tin or indium layer attached to the nickel layer increases the oxidation resistance of the terminal surface and reduces the occurrence of oxidation reaction on the aluminum terminal surface. At the same time, the tin or indium layer can provide stable and reliable electrical contact when the terminals are mated.

[0021] 4. After the conductor crimping part of the terminal is crimped and connected to the conductor, the serrated pits of the conductor crimping part can mechanically break the oxide layer on the surface of the conductor, forming a stable electrical contact and improving the connection performance between the terminal and the conductor; the insulation crimping part has a cross U-shaped structure, which can effectively increase the wrapping area between the terminal crimping part and the conductor insulation, and improve the connection reliability under vibration environment. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the connection between the alloy terminal and the wire of the present invention; Figure 2 This is a schematic diagram of the alloy terminal structure; Figure 3 This is a schematic diagram of the plating on the alloy terminal. Figure 4 A schematic diagram of the carbon coating layer on the conductor crimping portion of the terminal; Figure 5 This is a schematic diagram showing the connection between the conductor and the crimped part of the wire.

[0024] In the diagram: 1. Socket terminal, 2. Plug terminal, 3. Wire conductor, 4. Wire insulation, 5. Terminal head, 6. Conductor crimping part, 7. Insulation crimping part, 61. Serrated pit. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] Example 1, such as Figure 1 , Figure 2 , Figure 4 As shown, an ultra-lightweight, high-conductivity alloy terminal includes a terminal head 5 and a terminal tail made of aluminum alloy. Both the terminal head 5 and the terminal tail are coated with a nickel layer, and an indium layer is coated on the surface of the nickel layer. The terminal tail includes a conductor crimping portion 6, and a carbon coating layer is coated on the surface of the tin or indium layer in the crimping area of ​​the conductor crimping portion 6. The terminal head 5 is used for terminal mating, and the terminal tail is used for connection with a wire. The conductor crimping portion 6 is crimped to the conductor 3. The carbon coating layer on the crimping area of ​​the conductor crimping portion 6 prevents electrochemical corrosion between the aluminum terminal material and the copper conductor material. Using aluminum alloy as the base material for the terminal ensures both lightweight construction and increased terminal strength through material alloying, guaranteeing the structural reliability of the miniaturized terminal while maintaining its light weight. The entire surface of the terminal is coated with nickel and indium layers, providing stable and reliable electrical contact during terminal mating and preventing oxidation of the aluminum terminal surface.

[0027] Furthermore, the terminal includes a socket terminal 1 and a plug terminal 2, which are interlocked. Both the socket terminal 1 and the plug terminal 2 include a terminal head 5 and a terminal tail, which are integrally connected. The terminal head 5 and the terminal tail are made of aluminum alloy material through stamping and bending. The composition of the aluminum alloy material includes Cr, 0.15% to 0.35%; Cu, ≤0.1%; Fe, ≤0.4%; Mg, 2.2% to 2.8%; Mn, ≤0.10%; Si, ≤0.25%; Zn, ≤0.1%; Al, 95.7% to 97.7%; other elements total ≤0.15%, and other single elements ≤0.05%. The aluminum alloy material is lightweight, effectively reducing the weight of the terminal product, and also facilitating the miniaturization and weight reduction of the terminal. When the socket terminal 1 and the plug terminal 2 are plugged together, the indium layer attached to the surface of the terminal head 5 enables a stable and reliable electrical contact between the socket terminal 1 and the plug terminal 2; in addition, a nickel layer is provided between the terminal surface and the indium layer, and the nickel layer serves as a transition layer to increase the adhesion of the indium layer to the terminal.

[0028] Furthermore, the conductor crimping portion 6 has a U-shaped structure, with serrated recesses 61 on the inner side of the U-shaped structure. A carbon coating layer is attached to the surface of the serrated recesses 6. The serrated recesses 61 are elongated and arranged perpendicular to the terminal axis. Specifically, a carbon coating layer is provided on the inner wall of the U-shaped structure and the surface of the serrated recesses 6, ensuring complete coverage of the contact area between the conductor crimping portion 6 and the conductor 3, effectively isolating direct contact between the aluminum terminal and the copper conductor. In this embodiment, the carbon coating layer is applied to the inner wall of the conductor crimping portion 6 by spraying. When the conductor crimping portion 6 crimps the conductor 3, the unevenness of the crimping surface due to the serrated recesses 61 allows the crimping surface to break down the oxide layer on the surface of the conductor 3, forming a stable electrical contact between the conductor crimping portion 6 and the conductor 3, thus preventing electrochemical corrosion between the aluminum alloy terminal and the copper alloy conductor.

[0029] Furthermore, such as Figure 5 As shown, after the conductor crimping part 6 crimps the conductor 3, the side wall of the U-shaped structure bends and presses the conductor 3 tightly, so that the conductor 3 is in full contact with the inner wall of the conductor crimping part 6, ensuring the conductivity between the terminal and the conductor.

[0030] Furthermore, the carbon coating amount is 1.3~1.5 g / m². 2 In this embodiment, the carbon coating amount is 1.3 g / m². 2The carbon coating layer uses a mixture of conductive graphite and organic binder, applied to the crimping surface of the conductor crimping part 6 via electrostatic spraying. Specifically, the mixture of conductive graphite and organic binder is sprayed onto the inner wall of the U-shaped structure. This carbon coating layer prevents electrochemical corrosion at the contact point between the aluminum terminals and the copper wires, increasing their interfacial conductivity. The carbon coating amount is less than 1.3 g / m². 2 At that time, the carbon coating layer could not completely cover the crimping surface of the conductor crimping part 6; when the carbon coating amount was greater than 1.5 g / m 2 Sometimes, an excessively thick carbon coating can cause cracking during pressing. The carbon coating amount is 1.3 g / m². 2 The carbon coating can completely cover the crimping area without cracking during crimping due to excessive coating thickness, ensuring the integrity of the carbon coating after crimping. This ensures that the carbon coating can isolate the direct contact between the aluminum terminal and the copper wire after terminal crimping, eliminating potential difference and avoiding electrochemical corrosion between the terminal material and the conductor material.

[0031] Furthermore, such as Figure 3 As shown, the nickel layer attached to the surface of terminal head 5 has a thickness of 2.1~3μm. The indium layer attached to the surface of the nickel layer has a thickness of 1.5~5μm. In this embodiment, the nickel layer has a thickness of 3μm and the indium layer has a thickness of 5μm. The thicker indium layer has better oxidation resistance, preventing oxidation of the aluminum alloy terminal surface; the nickel layer, as a transition layer, enhances the adhesion of the indium layer.

[0032] Furthermore, the terminal tail also includes an insulating crimping portion 7, which has a cross-U-shaped structure. When the terminal is crimped to the wire, the insulating crimping portion 7 is pressed tightly against the wire insulation 4; the cross-U-shaped structure can increase the area of ​​the terminal crimping portion covering the wire insulation 4, thereby improving the reliability of the connection between the terminal and the wire under vibration.

[0033] Furthermore, the terminal head 5, conductor crimping part 6, and insulating skin crimping part 7 are integrally connected. The terminal head 5, conductor crimping part 6, and insulating skin crimping part 7 are made of aluminum alloy substrate by stamping and bending. The terminal manufacturing process is simple and conducive to the miniaturized mass production of terminals.

[0034] Example 2 differs from Example 2 in that it uses an ultralight, high-conductivity alloy terminal, such as... Figure 3 As shown, both the head and tail surfaces of terminal 5 are coated with a nickel layer, and a tin layer is attached to the surface of the nickel layer. The entire surface of the terminal is coated with both nickel and tin layers. During terminal mating, the nickel and tin layers provide stable and reliable electrical contact while preventing oxidation of the aluminum terminal surface.

[0035] Furthermore, the nickel layer attached to the surface of the terminal head 5 has a thickness of 2.1~3μm, and the tin layer attached to the surface of the nickel layer has a thickness of 2~5μm. In this embodiment, the thickness of the nickel layer is 3μm, and the thickness of the tin layer is 5μm. The thicker tin layer has better oxidation resistance, preventing oxidation of the aluminum alloy terminal surface; the nickel layer, as a transition layer, enhances the adhesion of the tin layer.

[0036] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An ultralight, high-conductivity alloy terminal, characterized in that, It includes a terminal head (5) and a terminal tail made of aluminum alloy material. Both the terminal head (5) and the terminal tail are coated with a nickel layer, and the nickel layer is coated with a tin layer or an indium layer. The terminal tail includes a conductor crimping part (6), and the tin layer or indium layer in the crimping area of ​​the conductor crimping part (6) is coated with a carbon coating layer.

2. The ultralight high-conductivity alloy terminal according to claim 1, characterized in that, The conductor crimping part (6) is a U-shaped structure, and a serrated pit (61) is provided on the inner side of the U-shaped structure. A carbon coating layer is attached to the surface of the serrated pit (6).

3. The ultralight high-conductivity alloy terminal according to claim 2, characterized in that, The serrated recess (61) is a long strip structure, and the serrated recess (61) is arranged in a direction perpendicular to the terminal axis.

4. The ultralight high-conductivity alloy terminal according to any one of claims 1 to 3, characterized in that, The carbon coating amount is 1.3~1.5 g / m². 2 .

5. The ultralight high-conductivity alloy terminal according to claim 4, characterized in that, The thickness of the nickel layer attached to the surface of the terminal head (5) is 2.1~3μm.

6. The ultralight high-conductivity alloy terminal according to claim 5, characterized in that, The thickness of the indium layer attached to the nickel layer surface is 1.5~5μm.

7. The ultralight high-conductivity alloy terminal according to claim 5, characterized in that, The thickness of the tin layer attached to the nickel layer surface is 2~5μm.

8. The ultralight high-conductivity alloy terminal according to any one of claims 1-3 and 5-7, characterized in that, The terminal tail also includes an insulating skin crimping part (7), which has a cross U-shaped structure.

9. The ultralight high-conductivity alloy terminal according to claim 8, characterized in that, The terminal head (5), conductor crimping part (6) and insulating skin crimping part (7) are integrated into a single connection structure.

10. The ultralight high-conductivity alloy terminal according to claim 1, characterized in that, The terminals are socket terminals (1) or plug terminals (2).

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