Coaxial copper-aluminum composite material and preparation method thereof

Abstract

The invention discloses a coaxial copper-aluminum composite material and a preparation method thereof, and belongs to the field of material forming. The coaxial copper-aluminum composite material is specifically formed by alternately and coaxially distributing copper and aluminum. Specifically, a copper plate and an aluminum plate are compounded together through an explosion method, the obtained layered composite plate is rolled, then the rolled copper-aluminum composite material is wound and drawn, and finally the coaxial copper-aluminum multi-layer composite wire is obtained. The coaxial copper-aluminum composite material prepared by the method is tight in combination, high in strength and wide in application.

Description

Technical Field

[0001] The invention relates to a coaxial copper-aluminum composite material and a preparation method thereof, and belongs to the field of material forming. Background Art

[0002] Metal materials occupy an important position in people's lives and are widely used. Although single metal materials have their own characteristics, with the development of science and technology, single metals can no longer meet the growing demand. Composite metal materials can not only maintain the properties of the original single metal, but also show more excellent performance. They are currently used in important industrial fields such as petroleum, chemical industry, aerospace, transportation and food.

[0003] Copper-aluminum material is a new type of material with wide application. It not only has the excellent electrical and thermal conductivity of copper, but also has the low density and low cost of aluminum. Currently, most preparation methods are rolling, extrusion and casting. The traditional copper-clad aluminum process is complicated, the bonding between copper and aluminum is poor, and the interface contact resistance is large. Summary of the invention

[0004] In view of the defects of the prior art, the first object of the present invention is to provide a coaxial copper-aluminum composite material. The coaxial copper-aluminum composite material provided by the present invention has a cross section in which copper and aluminum are coaxially distributed alternately.

[0005] The second object of the present invention is to provide a method for preparing a coaxial copper-aluminum composite material. The method provided by the present invention has a tight bond between copper and aluminum, is formed in one step, has a lighter weight, and can significantly reduce costs.

[0006] In order to achieve the above object, the present invention provides the following technical solutions: The invention provides a coaxial copper-aluminum composite material, wherein the cross section of the coaxial copper-aluminum composite material is a multilayer structure in which copper and aluminum are alternately coaxially distributed.

[0007] The coaxial copper-aluminum composite material provided by the present invention can have an outermost layer of copper or aluminum, and both can achieve excellent performance.

[0008] In a preferred embodiment, in the coaxial copper-aluminum composite material, the thickness of any copper layer is 0.1-0.3 mm, the thickness of any aluminum layer is 0.1-0.4 mm, and the thickness of any copper layer is ≤ the thickness of any aluminum layer.

[0009] The invention discloses a method for preparing a coaxial copper-aluminum composite material. The method comprises the following steps: performing explosive compounding on a copper plate and an aluminum plate to obtain a layered copper-aluminum composite plate, performing annealing treatment on the layered copper-aluminum composite plate, and then performing rolling to obtain a rolled composite plate. The rolled composite plate is continuously wound to obtain a multi-layer copper-aluminum composite material. The multi-layer copper-aluminum composite material is then drawn, and finally subjected to heat treatment to obtain the coaxial copper-aluminum composite material.

[0010] The coaxial copper-aluminum composite material provided by the present invention first adopts explosive rolling compounding to obtain a layered copper-aluminum composite plate. The layered copper-aluminum composite plate obtained by the explosive compounding is tightly combined, is easy to deform and will not crack during the heating and winding process, and can maintain good interface contact. Subsequently, the copper-aluminum layered composite material obtained after rolling is continuously wound to obtain a concentric circle-like multi-layer copper-clad aluminum composite material, and then after drawing, the coaxial copper-aluminum composite material is obtained.

[0011] In a preferred solution, the thickness of the copper plate is 2-10 mm, the thickness of the aluminum plate is 2-10 mm, and the thickness of the copper plate is ≤ the thickness of the aluminum plate, preferably the thickness of the copper plate is < the thickness of the aluminum plate.

[0012] In the present invention, the copper plate is controlled to be slightly thinner than the aluminum plate. The mass of copper is heavier than that of aluminum, so that the specific gravity can be reduced. At the same time, a slightly thin copper plate is more conducive to winding after heating, and a coaxial copper-aluminum composite material with close contact between layers can be obtained.

[0013] In a preferred embodiment, the explosive composite process is as follows: placing a copper plate on a platform, evenly placing a support frame on its surface, placing an aluminum plate on the support frame, and laying explosives on its surface, performing explosive composite to obtain a copper-aluminum composite layered material, wherein the height of the support frame is 2-6 mm.

[0014] In the actual operation process, the copper plate and the aluminum plate are polished to remove the surface oxide layer before the explosive composite.

[0015] In a preferred embodiment, the explosives used in the explosive composite are composed, by mass percentage, of 80-85% expanded ammonium nitrate, 6-8% porous ammonium nitrate, 3-4% diesel, 3-5% powdered emulsion explosive, and 3-4% salt.

[0016] The layered copper-aluminum composite plate with a flat interface is obtained by explosive compounding under the above-mentioned explosives. Not only is the interface tightly bonded, but it is also easy to deform and will not crack during the heating and winding process, and can maintain good contact of the interface.

[0017] In a preferred embodiment, the temperature for annealing the layered copper-aluminum composite plate is 250-450° C., and the annealing time is 2-8 hours.

[0018] According to a preferred embodiment, during the rolling, 3-5 rough rolling passes are performed first, followed by 4-9 finish rolling passes. The deformation amount of the rough rolling is 13-17%, the total deformation amount is 50-65%, and the deformation amount of each finish rolling pass is 10-12%.

[0019] In the present invention, 3-5 passes of rough rolling are performed first, and then 4-9 passes of finish rolling are performed, so that the target thickness can be accurately obtained.

[0020] Preferably, the thickness of the rolled composite plate is 0.1-0.5 mm. The performance is optimal if the thickness of the rolled composite plate is controlled within this range. If it is too thick, it is not conducive to winding. If it is too thin, the bonding between layers is not tight enough during the winding process.

[0021] In a preferred embodiment, the winding process is as follows: firstly, the rolled composite plate is heated to 400-500°C, and then the rolled composite plate is wound around a round tube with a diameter of 0.01-0.04 mm, and the round tube is pulled out after winding. The rolled composite plate is heated to the above temperature, and the diameter of the round tube is controlled within the above range, and the coaxial copper-aluminum composite material finally obtained has close contact between the layers. If the diameter of the round tube is too large, it is not conducive to close contact between the layers during the winding process.

[0022] In a preferred embodiment, the drawing is continuous hot drawing, the hot drawing temperature is 400-550°C, the hot drawing deformation is 8-13%, and the number of passes is 6-15. By hot drawing within the above parameter range, a coaxial copper-aluminum composite material with close interlayer contact and a target diameter can be obtained.

[0023] Beneficial Effects (1) Aluminum and copper are compounded to give copper the excellent electrical conductivity and thermal conductivity, and aluminum the good plasticity and light specific gravity. The resulting multi-layer coaxial copper-aluminum wire material also has excellent electrical conductivity and reduces costs.

[0024] (2) Explosive bonding is a technique for welding metals using explosive explosions. It can bond metals with very different properties such as melting point, strength, thermal expansion coefficient, etc., and avoid the formation of brittle metal compounds. The materials bonded by explosive bonding are tightly bonded and widely used. The present invention uses explosive bonding to bond aluminum and copper. The obtained copper-aluminum layered composite material is tightly bonded and formed in one step. The material is then wound to obtain a coaxial multilayer copper-aluminum material, which fills the gap in the coaxial multilayer copper-aluminum material market and avoids the complexity of casting and other processes. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is an explosive composite copper-aluminum layered material.

[0026] Figure 2 This is a cross-sectional view of a coaxial copper-aluminum composite material. DETAILED DESCRIPTION

[0027] In order to make the technical problems to be solved, technical solutions and advantages of the present invention more clear, they are described in detail below in conjunction with specific embodiments.

[0028] Example 1 Copper and aluminum plates with thicknesses of 3 mm and 4 mm, respectively, were selected, and the surfaces of the copper and aluminum plates were polished to remove surface impurities, oxide layers, and passivation layers. The copper plate was placed on a platform, and a support frame was evenly placed on its surface. The height of the support frame was 3 mm. The treated aluminum plate was then placed on the support frame, and explosives were laid on the aluminum plate. The explosive composition was as follows: 84% expanded ammonium nitrate, 6% porous ammonium nitrate, 3% diesel, 4% powdered emulsion explosive, and 3% salt. The explosives were detonated to obtain an explosively composite layered copper-aluminum metal plate. The layered copper-aluminum metal plate was annealed at 400°C for 4h and then rolled, firstly rough-rolled for 5 times and then fine-rolled for 9 times until a rolled composite plate with a thickness of 0.5 mm was obtained, and then the rolled composite plate was heated to 450°C, and then the rolled composite plate was wound around a round tube with a diameter of 0.02 mm. After winding, the round tube was pulled out, and finally the wound multi-layer coaxial copper-aluminum rod-shaped material was continuously hot-drawn at a temperature of 450°C and 10 times, and finally a coaxial copper-aluminum composite material was obtained with a total thickness of 1 mm, wherein the thickness of any copper layer was 0.15 mm and the thickness of any aluminum layer was 0.2 mm.

[0029] Example 2 Copper and aluminum plates with thicknesses of 2 mm and 4 mm, respectively, were selected, and the surfaces of the copper and aluminum plates were polished to remove surface impurities, oxide layers and passivation layers. The copper plate was placed on a platform, and a support frame was evenly placed on its surface. The height of the support frame was 3 mm. The treated aluminum plate was then placed on the support frame, and explosives were laid on the aluminum plate. The explosive composition was as follows: 84% expanded ammonium nitrate, 6% porous ammonium nitrate, 3% diesel, 4% powdered emulsion explosive, and 3% salt. The explosives were detonated to obtain an explosively composite layered copper-aluminum metal plate. The layered copper-aluminum metal plate is annealed at 400°C for 2h and then rolled, firstly by 4 rough rolling and then by 6 finishing rolling, until a rolled composite plate with a thickness of 0.3-mm is obtained, and then the rolled composite plate is heated to 450°C, and then the rolled composite plate is wound around a round tube with a diameter of 0.02 mm, and the round tube is pulled out after winding, and finally the wound multi-layer coaxial copper-aluminum rod-shaped material is continuously hot-drawn, the hot-drawing temperature is 450°C, the number of hot-drawing passes is 10, and finally a coaxial copper-aluminum composite material is obtained, the total thickness of which is 0.6mm, and the thickness of any copper layer is 0.1mm, and the thickness of any aluminum layer is 0.15mm.

[0030] Example 3 Copper and aluminum plates with thicknesses of 2 mm and 5 mm were selected, and the surfaces of the copper and aluminum plates were polished to remove surface impurities, oxide layers and passivation layers. The copper plate was placed on a platform, and a support frame was evenly placed on its surface. The height of the support frame was 3 mm. Then the treated aluminum plate was placed on the support frame, and explosives were laid on the aluminum plate. The explosive composition was as follows: 84% expanded ammonium nitrate, 6% porous ammonium nitrate, 3% diesel, 4% powdered emulsion explosive, and 3% salt. The explosives were detonated to obtain an explosively composite layered copper-aluminum metal plate. The layered copper-aluminum metal plate is annealed at 400°C for 2h and then rolled, firstly performing 4 rough rolling passes and then 6 finish rolling passes until a rolled composite plate with a thickness of 0.4 mm is obtained, and then the rolled composite plate is heated to 450°C, and then the rolled composite plate is wound around a round tube with a diameter of 0.02 mm. After winding, the round tube can be pulled out, and finally the wound multi-layer coaxial copper-aluminum rod-shaped material is continuously hot-drawn, the hot-drawing temperature is 450°C, the number of hot-drawing passes is 9, and finally a coaxial copper-aluminum composite material is obtained, the total thickness of which is 0.7mm, and the thickness of any copper layer is 0.1mm, and the thickness of any aluminum layer is 0.2mm.

[0031] Comparative Example 1 The other conditions are the same as those in Example 1, except that the thickness of the composite plate after rolling is 1.5 mm, which not only increases the difficulty in winding, but also reduces the performance of the coaxial copper-aluminum composite material obtained in the end.

[0032] Comparative Example 2 The other conditions are the same as those in Example 1, except that the diameter of the wound round tube is 0.1 mm. The diameter of the round tube is too large, resulting in insufficient tightness between the layers after final drawing and reduced performance.

[0033] The conductivity of the obtained embodiment and comparative example was measured, and the results are listed in Table 1. From the data in Table 1, it can be seen that the coaxial copper-aluminum rod-shaped material obtained in the embodiment has excellent conductivity, while the comparative example has poorer performance than the embodiment due to parameters not within the scope of the present invention.

[0034]

Claims

1. A coaxial copper-aluminum composite material, characterized in that: The coaxial copper-aluminum composite material has a cross section of a multilayer structure in which copper and aluminum are alternately coaxially distributed.

2. The coaxial copper-aluminum composite material according to claim 1, characterized in that: In the coaxial copper-aluminum composite material, the thickness of any copper layer is 0.1-0.3 mm, the thickness of any aluminum layer is 0.1-0.4 mm, and the thickness of any copper layer is ≤ the thickness of any aluminum layer.

3. The method for preparing a coaxial copper-aluminum composite material according to claim 1 or 2, characterized in that: The copper plate and the aluminum plate are explosively composited to obtain a layered copper-aluminum composite plate, the layered copper-aluminum composite plate is annealed, and then rolled to obtain a rolled composite plate, the rolled composite plate is continuously wound to obtain a multi-layer copper-aluminum composite material, and then the multi-layer copper-aluminum composite material is drawn, and finally heat treated to obtain a coaxial copper-aluminum composite material.

4. The method for preparing a coaxial copper-aluminum composite material according to claim 3, characterized in that: The thickness of the copper plate is 2-10 mm, the thickness of the aluminum plate is 2-10 mm, and the thickness of the copper plate is ≤ the thickness of the aluminum plate.

5. The method for preparing a coaxial copper-aluminum composite material according to claim 3, characterized in that: The explosive composite process is as follows: placing a copper plate on a platform, evenly placing a support frame on the surface of the copper plate, placing an aluminum plate on the support frame, and laying explosives on the surface of the copper plate to perform explosive composite to obtain a copper-aluminum composite layered material, wherein the height of the support frame is 2-6 mm.

6. The method for preparing a coaxial copper-aluminum composite material according to claim 3 or 5, characterized in that: The explosives used in the explosive compound are composed of the following by mass percentage: 80-85% expanded ammonium nitrate, 6-8% porous ammonium nitrate, 3-4% diesel, 3-5% powdered emulsion explosive, and 3-4% salt.

7. The method for preparing a coaxial copper-aluminum composite material according to claim 3, characterized in that: The temperature for annealing the layered copper-aluminum composite plate is 250-450° C., and the annealing time is 2-8 hours.

8. The method for preparing a coaxial copper-aluminum composite material according to claim 3, characterized in that: During the rolling, 3-5 passes of rough rolling are performed first, and then 4-9 passes of finish rolling are performed. The deformation amount of the rough rolling is 13-17%, the total deformation amount is 50-65%, and the deformation amount of the finish rolling pass is 10-12%; The thickness of the rolled composite plate is 0.1-0.5 mm.

9. The method for preparing a coaxial copper-aluminum composite material according to claim 3, characterized in that: The winding process is as follows: firstly, the rolled composite plate is heated to 400-500° C., then the rolled composite plate is wound around a round tube with a diameter of 0.01-0.04 mm, and after the winding, the round tube is pulled out.

10. The method for preparing a coaxial copper-aluminum composite material according to claim 3, characterized in that: The drawing is continuous hot drawing, the temperature of the hot drawing is 400-550° C., the deformation amount of the hot drawing is 8-13%, and the number of passes is 6-15.

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