Copper clad aluminum wire with good conductivity

Abstract

The utility model discloses a copper clad aluminium wire with good conductive performance belongs to copper clad aluminium wire technical field, and its technical key points include copper clad aluminium wire body, and the copper clad aluminium wire body includes aluminium core and the copper layer of cladding in its outer periphery, the cross section of aluminium core is equilateral polygon, the volume proportion of copper layer is 10% 15%, the metallurgical bonding interface is formed through diffusion annealing between copper layer and aluminium core, the copper layer includes outer copper layer and combined copper layer, and the combined copper layer is located in the inside of outer copper layer. The utility model copper layer and aluminium core between through diffusion annealing form metallurgical bonding interface, and metallurgical bonding interface is Cu Al intermetallic compound transition layer, and adopts magnetron sputtering and deposits and forms combined copper layer on the surface of aluminium core, and makes combined copper layer fill the equilateral polygon of the cross section of aluminium core and every side all sets up arc type inner recess, thickens copper layer to target thickness through electroplating, until forms outer copper layer, effectively improves its copper aluminium combination performance, and the bending performance.

Description

Technical Field

[0001] This utility model belongs to the technical field of copper-clad aluminum wire, specifically relating to a copper-clad aluminum wire with good conductivity. Background Technology

[0002] Copper-clad aluminum wire is a composite material conductor with an aluminum core and an outer copper sheath. Due to its combination of copper's excellent conductivity and aluminum's low density and low cost, it has been widely used in numerous fields such as wires and cables, electronics, and communications. For example, in power transmission, copper-clad aluminum wire can be used to manufacture overhead conductors and cables; in electronics, it can be used to manufacture transformer windings and motor coils; and in communications, it can be used to manufacture radio frequency cables and signal lines.

[0003] Despite the many advantages of copper-clad aluminum wire, the current copper-clad aluminum wire on the market still has certain shortcomings in terms of conductivity. Due to the insufficient bonding force between the copper layer and the aluminum core under the existing production process, the current will encounter a large interface resistance during conduction, which will affect the overall conductivity of the copper-clad aluminum wire. Utility Model Content

[0004] The purpose of this invention is to provide a copper-clad aluminum wire with good conductivity to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a copper-clad aluminum wire with good conductivity, comprising a copper-clad aluminum wire body, the copper-clad aluminum wire body comprising an aluminum core and a copper layer covering its outer periphery, the cross-section of the aluminum core being an equilateral polygon, the volume ratio of the copper layer being 10%-15%, and the copper layer and the aluminum core forming a metallurgical bonding interface through diffusion annealing.

[0006] As a further embodiment of this utility model, the copper layer includes an outer copper layer and a bonding copper layer, wherein the bonding copper layer is located inside the outer copper layer and is tightly bonded to the outer surface of the aluminum core.

[0007] As a further embodiment of this invention, the cross-section of the aluminum core has an equilateral polygon with no fewer than 32 sides.

[0008] As a further embodiment of this utility model, each side of the equilateral polygon of the cross-section of the aluminum core is provided with an arc-shaped concave surface, and the arc-shaped concave surface is provided with a polished surface.

[0009] As a further embodiment of this utility model, the thickness of the copper layer has a uniformity deviation of ≤3% along the circumferential direction, and the surface roughness Ra of the copper layer is ≤0.5μm.

[0010] As a further embodiment of this invention, the metallurgical bonding interface is a Cu-Al intermetallic compound transition layer, and the thickness of the metallurgical bonding interface is 1-2 μm.

[0011] As a further embodiment of this utility model, the copper layer is oxygen-free copper with an oxygen content of ≤5ppm, the aluminum core is industrial pure aluminum, and 0.2-0.4wt% of rare earth elements are added to the aluminum core to refine the grain size to ≤15μm.

[0012] As a further embodiment of this invention, the outer surface of the copper-clad aluminum wire body is coated with a 5-8 μm thick tin-based anti-oxidation coating, which has a softening temperature ≥150℃.

[0013] Compared with the prior art, the beneficial effects of this utility model are:

[0014] 1. In this invention, a metallurgical bonding interface is formed between the copper layer and the aluminum core through diffusion annealing. The metallurgical bonding interface is a Cu-Al intermetallic compound transition layer with a thickness of 1-2 μm. The diffusion annealing forms a nanoscale transition layer, and the interface bonding strength is increased to ≥50 MPa.

[0015] 2. This utility model uses magnetron sputtering to deposit a bonding copper layer on the surface of an aluminum core, and the bonding copper layer fills the equilateral polygon of the cross-section of the aluminum core and each side has an arc-shaped concave opening. The copper layer is thickened to the target thickness by electroplating until an outer copper layer is formed, which effectively improves its copper-aluminum bonding performance and bending performance.

[0016] 3. This utility model refines the grain size to ≤15μm by adding 0.2-0.4wt% rare earth elements into the aluminum core. The rare earth element doping suppresses aluminum grain boundary scattering, thereby increasing the overall conductivity by 10% compared with similar products. Attached Figure Description

[0017] Figure 1 This is a perspective view of the present utility model;

[0018] Figure 2 This utility model Figure 1 A partial exploded view;

[0019] Figure 3 This utility model Figure 2 A magnified view of a portion of the image.

[0020] In the diagram: 1. Copper-clad aluminum wire body; 2. Copper layer; 3. Outer copper layer; 4. Bonding copper layer; 5. Aluminum core; 6. Arc-shaped concave shape; 7. Polished surface. Detailed Implementation

[0021] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0022] Please see Figures 1-3 This utility model provides a copper-clad aluminum wire with good conductivity, including a copper-clad aluminum wire body 1, which includes an aluminum core 5 and a copper layer 2 covering its outer periphery. The cross-section of the aluminum core 5 is an equilateral polygon, and the volume ratio of the copper layer 2 is 10%-15%, thereby balancing cost and conductivity. Compared with the traditional process (>20%), the cost is reduced by more than 30%. The copper layer 2 and the aluminum core 5 form a metallurgical bonding interface through diffusion annealing. The metallurgical bonding interface is a Cu-Al intermetallic compound transition layer with a thickness of 1-2μm. Diffusion annealing forms a nanoscale transition layer, and the interface bonding strength is increased to ≥50MPa.

[0023] The copper layer 2 in this invention includes an outer copper layer 3 and a bonding copper layer 4. The bonding copper layer 4 is located inside the outer copper layer 3 and is tightly bonded to the outer surface of the aluminum core 5.

[0024] The aluminum core 5 in this invention has an equilateral polygon cross-section with no less than 32 sides. Each side of the equilateral polygon cross-section of the aluminum core 5 is provided with an arc-shaped concave 6, and the arc-shaped concave 6 is provided with a ground surface 7. The magnetron sputtering + electroplating composite process can achieve a copper layer thickness accuracy of ±1μm, which is suitable for continuous production.

[0025] In this invention, the thickness of the copper layer 2 has a uniformity deviation of ≤3% along the circumferential direction, the surface roughness Ra of the copper layer 2 is ≤0.5μm, the copper layer 2 is oxygen-free copper with an oxygen content of ≤5ppm, the aluminum core 5 is industrial pure aluminum, and 0.2-0.4wt% of rare earth elements (Ce, La) are added to the aluminum core 5 to refine the grain size to ≤15μm. The doping of rare earth elements suppresses aluminum grain boundary scattering, thereby increasing the overall conductivity by 10% compared with similar products.

[0026] In this invention, the outer surface of the copper-clad aluminum wire body 1 is coated with a 5-8μm thick tin-based anti-oxidation coating with a softening temperature ≥150℃, thereby improving the anti-oxidation performance of the copper-clad aluminum wire body 1.

[0027] The preparation process involves the following steps:

[0028] S1: Electropolish the aluminum core 5 to make its surface roughness Ra < 1.2μm;

[0029] S2: Under inert gas protection, the aluminum core 5 is kept at 300-400℃ for 2-3 hours to form a Cu-Al intermetallic compound transition layer with a thickness of 1-2μm on the outer surface.

[0030] S3: Then, magnetron sputtering is used to deposit a bonding copper layer 4 on the surface of the aluminum core 5, and the bonding copper layer 4 fills the equilateral polygon of the cross section of the aluminum core 5 and each side has an arc-shaped concave 6. The copper layer is thickened to the target thickness by electroplating until the outer copper layer 3 is formed.

[0031] The electronic components and modules used in this utility model can all be parts that are commonly used in the market and can achieve the specific functions in this case. The specific models and sizes can be selected and adjusted according to actual needs.

[0032] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A copper-clad aluminum wire with good conductivity, comprising a copper-clad aluminum wire body (1), characterized in that: The copper-clad aluminum wire body (1) includes an aluminum core (5) and a copper layer (2) covering its outer periphery. The cross-section of the aluminum core (5) is an equilateral polygon. The volume ratio of the copper layer (2) is 10%-15%. The copper layer (2) and the aluminum core (5) form a metallurgical bonding interface through diffusion annealing.

2. The copper-clad aluminum wire with good conductivity according to claim 1, characterized in that: The copper layer (2) includes an outer copper layer (3) and a bonding copper layer (4). The bonding copper layer (4) is located inside the outer copper layer (3) and is closely attached to the outer surface of the aluminum core (5).

3. The copper-clad aluminum wire with good conductivity according to claim 1, characterized in that: The cross-section of the aluminum core (5) has an equilateral polygon with no less than 32 sides.

4. The copper-clad aluminum wire with good conductivity according to claim 3, characterized in that: The aluminum core (5) has an arc-shaped concave (6) on each side of the equilateral polygon of the cross-section, and the arc-shaped concave (6) has a ground surface (7).

5. The copper-clad aluminum wire with good conductivity according to claim 1, characterized in that: The thickness of the copper layer (2) has a uniformity deviation of ≤3% along the circumferential direction, and the surface roughness Ra of the copper layer (2) is ≤0.5μm.

6. The copper-clad aluminum wire with good conductivity according to claim 1, characterized in that: The metallurgical bonding interface is a Cu-Al intermetallic compound transition layer, and the thickness of the metallurgical bonding interface is 1-2 μm.

7. The copper-clad aluminum wire with good conductivity according to claim 1, characterized in that: The copper layer (2) is oxygen-free copper, and the aluminum core (5) is industrial pure aluminum.

8. The copper-clad aluminum wire with good conductivity according to claim 1, characterized in that: The outer surface of the copper-clad aluminum wire body (1) is coated with a 5-8 μm thick tin-based anti-oxidation coating.

Images