A copper-clad aluminum alloy composite sheet strip and a method for manufacturing the same

Abstract

The present application relates to a kind of copper clad aluminum alloy composite plate strip and its preparation method, belong to the preparation field of metal plate strip.The preparation method of copper clad aluminum alloy composite plate strip of the present application includes the following steps: the zirconium cerium aluminum alloy liquid of 690~710 ℃ is introduced to the cast rolling between two zirconium chromium copper alloy strip;During cast rolling, the temperature of roller is controlled to be 150~220 ℃, and the walking speed of copper clad aluminum alloy composite plate strip is 0.5~0.8 m / min.The preparation method of copper clad aluminum alloy composite plate strip of the present application, by controlling the temperature of roller and the walking speed of zirconium chromium copper alloy strip, can be prepared with nanocrystalline intermetallic compound and gradient micrometer crystal solid solution structure metallurgical bonding interface high-conductivity high-strength copper clad aluminum alloy composite plate strip, and copper clad aluminum alloy composite plate preparation efficiency is high.

Description

Technical Field

[0001] This invention relates to a copper-clad aluminum alloy composite plate and strip and its preparation method, belonging to the field of metal plate and strip preparation. Background Technology

[0002] High-conductivity, high-strength copper-clad aluminum alloys are functional and structural composite materials. They combine the advantages of low resistivity of the outer copper alloy layer with the lightweight and inexpensive properties of the core pure aluminum layer. This allows copper and aluminum to complement each other in terms of cost and performance, resulting in a highly synergistic cost-performance effect. They are widely used in power transmission, electronic communications, and new energy fields, achieving the goal of "saving copper with aluminum" and promoting the optimal integration of resources.

[0003] High-speed rail, aviation, and other fields not only require copper-clad aluminum composite conductive bars or plates to be lightweight and highly conductive, but also require high strength. While currently mature industrial pure copper-clad aluminum composite plates possess good electrical conductivity, their strength is relatively low and cannot meet these requirements. To improve the strength of the composite plate while ensuring high conductivity, existing technologies typically use high-strength aluminum alloys as the core layer during the preparation of copper-clad aluminum composite plates. Even so, the strength of the resulting copper-clad aluminum composite plate strip is difficult to reach 350 MPa. Furthermore, using a high-strength, high-conductivity copper alloy for the surface layer is problematic because its high strength and high conductivity are based on a complex and rigorous manufacturing process. When using double-liquid core-filling continuous casting, the copper-clad aluminum alloy composite is not suitable for the original high-strength, high-conductivity copper alloy manufacturing process, and the performance of the copper alloy layer cannot be fully utilized. Therefore, the conductivity and strength of the composite plate cannot be synergistically balanced. Summary of the Invention

[0004] The purpose of this invention is to provide a method for preparing copper-clad aluminum alloy composite strips, which produces copper-clad aluminum alloy composite strips with both high conductivity and strength.

[0005] The present invention also provides a copper-clad aluminum alloy composite plate and strip prepared by the above preparation method.

[0006] To achieve the above objectives, the technical solution adopted in the preparation method of the copper-clad aluminum alloy composite plate and strip of the present invention is as follows:

[0007] A method for preparing copper-clad aluminum alloy composite strip includes the following steps: introducing molten zirconium-cerium-aluminum alloy at 690-710℃ between two zirconium-chromium-copper alloy strips for casting and rolling; during the casting and rolling process, controlling the temperature of the rolls at 150-220℃, and the running speed of the copper-clad aluminum alloy composite strip at 0.5-0.8m / min.

[0008] The method for preparing copper-clad aluminum alloy composite strip of the present invention controls the temperature of the rolls and the running speed of the zirconium-chromium-copper alloy strip during the casting and rolling process. Copper element is dissolved in aluminum to form a gradient micron-crystalline (copper) aluminum solid solution at the interface of zirconium-cerium aluminum alloy and zirconium-chromium-copper alloy. The concentration of copper element gradually decreases to zero from the interface to the aluminum side, thereby obtaining a high-conductivity and high-strength copper-clad aluminum alloy composite strip with a metallurgical bonding interface of nanocrystalline intermetallic compound and gradient micron-crystalline solid solution structure. The preparation efficiency of copper-clad aluminum alloy composite strip is high.

[0009] The copper-clad aluminum alloy composite strip prepared by the method of the present invention has a conductivity of up to 66-70% IACS and a tensile strength of up to 350-400MPa.

[0010] Furthermore, the temperature of the zirconium-cerium aluminum alloy melt is 690–700°C. During the casting and rolling process, the temperature of the rolls is controlled at 150–200°C, and the running speed of the copper-clad aluminum alloy composite strip is 0.65–0.8 m / min.

[0011] Furthermore, the thickness of the zirconium-chromium-copper alloy layer in the copper-clad aluminum alloy composite strip is 30-40% (the total percentage of the two zirconium-chromium-copper alloy layers), for example, 33-40%. The thickness of the copper-clad aluminum alloy composite strip is 8-14 mm, for example, 8-12 mm.

[0012] Further, the zirconium-chromium-copper alloy strip is composed of the following components by mass percentage: 0.15–0.20% zirconium, 0.6–0.8% chromium, and the balance being copper. For example, the zirconium-chromium-copper alloy strip is composed of the following components by mass percentage: 0.16–0.20% zirconium, 0.65–0.75% chromium, and the balance being copper. The zirconium-chromium-copper alloy strip composed of these elements has high electrical conductivity and high tensile strength. The thickness of the zirconium-chromium-copper alloy strip is 1.5–2 mm, for example, 1.5 mm. The zirconium-chromium-copper alloy strip is prepared by hot rolling, solution treatment, cold rolling, and aging treatment of a zirconium-chromium-copper alloy ingot. Before introducing the molten zirconium-cerium-aluminum alloy between the two zirconium-chromium-copper alloy strips, the zirconium-chromium-copper alloy strips are first degreased, deoiled, and polished.

[0013] Further, the zirconium-cerium-aluminum alloy liquid is composed of the following components by mass percentage: zirconium 0.15–0.2%, cerium 0.01–0.02%, with the balance being aluminum. For example, the zirconium-cerium-aluminum alloy liquid is composed of the following components by mass percentage: zirconium 0.15–0.2%, cerium 0.02%, with the balance being aluminum. The zirconium element in the zirconium-cerium-aluminum alloy liquid has good wettability with the zirconium-chromium-copper alloy plate, resulting in high interfacial bonding strength. Furthermore, zirconium strengthens the aluminum alloy, and cerium refines the aluminum alloy grains, which can further improve the strength of the aluminum alloy, thereby increasing the strength of the resulting copper-clad aluminum composite strip.

[0014] Furthermore, the molten zirconium-cerium-aluminum alloy flows out through the distribution casting nozzle and simultaneously contacts two zirconium-chromium-copper alloy plates and strips; the height of the molten zirconium-cerium-aluminum alloy at the outlet of the distribution casting nozzle is 10-16 mm, for example, 10-14 mm.

[0015] Furthermore, the length of the casting and rolling zone is 50–80 mm, for example, 60, 65, or 70 mm. It can be understood that the length of the casting and rolling zone refers to the distance from the liquid outlet end of the casting nozzle to the center line of the two rolls.

[0016] Furthermore, the casting and rolling process is a horizontal continuous casting and rolling process. The two zirconium-chromium-copper alloy strips are guided by upper and lower guide rollers, respectively, through the upper and lower rolls into the casting and rolling mill. Typically, the gap between the upper and lower rolls is set to 90-98% of the total thickness of the copper-clad aluminum alloy composite strip.

[0017] Furthermore, before the two zirconium-chromium-copper alloy strips come into contact with the molten zirconium-cerium-aluminum alloy, the zirconium-chromium-copper alloy strips are preheated to 150-160°C.

[0018] The technical solution adopted by the copper-clad aluminum alloy composite strip of the present invention is as follows:

[0019] A copper-clad aluminum alloy composite strip prepared by the above-mentioned method.

[0020] The copper-clad aluminum alloy composite strip of the present invention is prepared by the above-mentioned method. The copper-clad aluminum alloy composite strip has a zirconium-cerium-aluminum alloy core layer and a layered zirconium-chromium-copper alloy surface layer parallel to it. A nanocrystalline CuAl2 layer with a thickness of 0.3-0.5 μm and a gradient microcrystalline (copper) aluminum solid solution interface layer are formed between the zirconium-chromium-copper alloy and the zirconium-cerium-aluminum alloy. Its conductivity can reach 66-70% IACS and its tensile strength can reach 350-400 MPa. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the macroscopic structure of the copper-clad aluminum alloy composite strip prepared in Example 1;

[0022] Figure 2 This is a photograph of the microstructure at the copper-aluminum interface of the copper-clad aluminum alloy composite strip prepared in Example 1.

[0023] Among them, 1-zirconium-chromium-copper alloy layer, 2-zirconium-cerium-aluminum alloy layer. Detailed Implementation

[0024] The technical solution of the present invention will be further described below with reference to specific embodiments.

[0025] Example 1

[0026] The preparation method of the copper-clad aluminum alloy composite strip in this embodiment specifically includes the following steps:

[0027] Industrial pure aluminum ingots and aluminum-zirconium alloy ingots are melted at 690°C, and then aluminum-cerium alloy ingots are added and melted at 700°C to obtain a zirconium-cerium aluminum alloy liquid. The zirconium-cerium aluminum alloy liquid is composed of the following components by mass percentage: 0.15% zirconium, 0.02% cerium, and the balance being aluminum.

[0028] Two zirconium-chromium-copper alloy strips with a thickness of 1.5 mm were degreased and deoiled, and then fed into the casting and rolling mill through the upper and lower rolls respectively. The upper and lower rolls preheated the zirconium-chromium-copper alloy strips to 160°C, and the gap between the upper and lower rolls was set to 7.2 mm. The zirconium-chromium-copper alloy strips used were prepared by hot rolling, solution treatment, cold rolling and aging treatment of zirconium-chromium-copper alloy ingots. The zirconium-chromium-copper alloy strips were composed of the following components by mass percentage: Zr 0.16%, Cr 0.6%, and the balance being copper.

[0029] The zirconium-cerium-aluminum alloy melt, at a temperature of 690℃, is horizontally injected into a distribution casting nozzle after filtering out slag. The melt enters between two zirconium-chromium-copper alloy strips at the nozzle outlet boundary and simultaneously contacts both strips before entering the space between the upper and lower rolls for continuous horizontal casting and rolling. This produces a high-conductivity, high-strength copper-clad aluminum alloy composite strip with a metallurgical interface of nanocrystalline intermetallic compounds and gradient microcrystalline solid solution structures. During the casting and rolling process, the height of the zirconium-cerium-aluminum alloy melt at the nozzle outlet is controlled at 10mm, and the distance from the nozzle outlet end to the center lines of the upper and lower rolls is 60mm. During the casting and rolling process, the roll temperature is controlled at 180℃ by adjusting the water flow rate in the water-cooled rolls, and the strip speed is 0.8m / min.

[0030] The copper-clad aluminum alloy composite strip prepared in this embodiment is as follows: Figure 1 As shown, it includes a zirconium-chromium-copper alloy layer 1 and a zirconium-cerium-aluminum alloy layer 2, with a total thickness of 8 mm. Each zirconium-chromium-copper alloy layer is 1.5 mm thick, and the remaining thickness is a zirconium-cerium-aluminum alloy layer; the microstructure is as follows. Figure 2 As shown, a 0.2 μm thick nanocrystalline CuAl2 layer and a gradient microcrystalline (copper) aluminum solid solution layer are formed at the copper-aluminum interface. The gradient microcrystalline (copper) aluminum solid solution at the interface is a solid solution formed by copper element dissolved in aluminum, and the copper element concentration gradually decreases from 5.65% to zero from the interface to the aluminum side. The copper-clad aluminum alloy composite strip prepared in this embodiment has a conductivity of 66% IACS and a tensile strength of 370 MPa.

[0031] Example 2

[0032] The method for preparing the copper-clad aluminum alloy composite strip in this embodiment includes the following steps:

[0033] Industrial pure aluminum ingots and aluminum-zirconium alloy ingots are melted at 700°C, and then aluminum-cerium alloy ingots are added and melted at 710°C to obtain a zirconium-cerium aluminum alloy liquid. The zirconium-cerium aluminum alloy liquid is composed of the following components by mass percentage: 0.2% zirconium, 0.02% cerium, and the balance being aluminum.

[0034] Two zirconium-chromium-copper alloy strips with a thickness of 2 mm are degreased and deoiled, and then fed into the casting and rolling mill through the upper and lower rolls respectively. The upper and lower rolls are preheated to 150°C, and the gap between the upper and lower rolls is set to 9.8 mm. The zirconium-chromium-copper alloy strips used are prepared by hot rolling, solution treatment, cold rolling and aging treatment of zirconium-chromium-copper alloy ingots. The zirconium-chromium-copper alloy strips are composed of the following components by mass percentage: Zr 0.2%, Cr 0.7%, and the balance is copper.

[0035] The zirconium-cerium-aluminum alloy melt, at a temperature of 700℃, is horizontally injected into a distribution casting nozzle after filtering out slag. The melt enters between two zirconium-chromium-copper alloy strips at the nozzle outlet boundary and contacts them before entering the space between upper and lower rolls for continuous horizontal casting and rolling. This produces a high-conductivity, high-strength copper-clad aluminum alloy composite strip with a metallurgical interface of nanocrystalline intermetallic compounds and gradient microcrystalline solid solution structures. During the casting and rolling process, the height of the zirconium-cerium-aluminum alloy melt at the nozzle outlet is controlled at 11mm, and the distance from the nozzle outlet end to the center lines of the upper and lower rolls is 70mm. During the casting and rolling process, the roll temperature is controlled at 150℃ by adjusting the water flow rate in the water-cooled rolls, and the strip speed is 0.8m / min.

[0036] The copper-clad aluminum alloy composite strip prepared in this embodiment has a total thickness of 10 mm, with each zirconium-chromium-copper alloy layer having a thickness of 2 mm, and the remaining thickness consisting of zirconium-cerium-aluminum alloy layers. A 0.4 μm thick nanocrystalline CuAl2 layer and a gradient microcrystalline (copper)-aluminum solid solution layer are formed at the copper-aluminum interface. The gradient microcrystalline (copper)-aluminum solid solution at the interface is a solid solution formed by copper dissolved in aluminum, and the copper concentration gradually decreases from 5.7% to zero from the interface to the aluminum side. The copper-clad aluminum alloy composite strip prepared in this embodiment achieves a conductivity of 70% IACS and a tensile strength of 380 MPa.

[0037] Example 3

[0038] The method for preparing the copper-clad aluminum alloy composite strip in this embodiment includes the following steps:

[0039] Industrial pure aluminum ingots and aluminum-zirconium alloy ingots are melted at 700°C, and then aluminum-cerium alloy ingots are added and melted at 710°C to obtain a zirconium-cerium aluminum alloy liquid. The zirconium-cerium aluminum alloy liquid is composed of the following components by mass percentage: 0.18% zirconium, 0.02% cerium, and the balance being aluminum.

[0040] Two zirconium-chromium-copper alloy strips with a thickness of 2 mm are degreased and deoiled, and then fed into the casting and rolling mill through the upper and lower rolls respectively. The upper and lower rolls preheat the zirconium-chromium-copper alloy strips to 160°C, and the gap between the upper and lower rolls is set to 11.6 mm. The zirconium-chromium-copper alloy strips used are prepared by hot rolling, solution treatment, cold rolling and aging treatment of zirconium-chromium-copper alloy ingots. The zirconium-chromium-copper alloy strips are composed of the following components by mass percentage: Zr 0.17%, Cr 0.6%, and the balance is copper.

[0041] The zirconium-cerium-aluminum alloy melt, at a temperature of 700℃, is horizontally injected into a distribution casting nozzle after filtering out slag. The melt enters between two zirconium-chromium-copper alloy strips at the nozzle outlet boundary and contacts them before entering the space between upper and lower rolls for continuous horizontal casting and rolling. This produces a high-conductivity, high-strength copper-clad aluminum alloy composite strip with a metallurgical interface of nanocrystalline intermetallic compounds and gradient microcrystalline solid solution structures. During the casting and rolling process, the height of the zirconium-cerium-aluminum alloy melt at the nozzle outlet is controlled at 14mm, and the distance from the nozzle outlet end to the center lines of the upper and lower rolls is 65mm. The roll temperature is controlled at 200℃ by adjusting the water flow rate in the water-cooled rolls, and the strip speed is 0.65m / min.

[0042] The copper-clad aluminum alloy composite strip prepared in this embodiment has a total thickness of 12 mm, with each zirconium-chromium-copper alloy layer having a thickness of 2 mm (4 mm in total for both layers), and the remaining thickness being a zirconium-cerium-aluminum alloy layer. A 0.4 μm thick nanocrystalline CuAl2 layer and a gradient microcrystalline (copper)-aluminum solid solution layer are formed at the copper-aluminum interface. The gradient microcrystalline (copper)-aluminum solid solution at the interface is a solid solution formed by copper dissolved in aluminum, and the copper concentration gradually decreases from 5.68% at the interface to zero at the aluminum side. The copper-clad aluminum alloy composite strip prepared in this embodiment achieves a conductivity of 68% IACS and a tensile strength of 370 MPa.

[0043] Example 4

[0044] The copper-clad aluminum alloy composite strip in this embodiment is prepared by the method of embodiment 1, embodiment 2, or embodiment 3 above, and will not be described again here.

Claims

1. A method for preparing a copper-clad aluminum alloy composite plate or strip, characterized in that: Includes the following steps: A molten zirconium-cerium-aluminum alloy at 690-710℃ is introduced between two zirconium-chromium-copper alloy strips preheated to 150-160℃ for casting and rolling. During the casting and rolling process, the temperature of the rolls is controlled at 150-220℃, and the running speed of the copper-clad aluminum composite strip is 0.5-0.8m / min. The zirconium-cerium-aluminum alloy liquid is composed of the following components by mass percentage: zirconium 0.15~0.2%, cerium 0.01~0.02%, with the balance being aluminum; a nanocrystalline CuAl2 layer and a gradient microcrystalline copper-aluminum solid solution structure are formed at the interface of the copper-clad aluminum alloy composite plate and strip.

2. The method for preparing copper-clad aluminum alloy composite strip according to claim 1, characterized in that: The zirconium-chromium-copper alloy layer in the copper-clad aluminum alloy composite strip accounts for 30-40% of the total thickness.

3. The method for preparing copper-clad aluminum alloy composite strip according to claim 1 or 2, characterized in that: The thickness of the copper-clad aluminum alloy composite strip is 8~14mm.

4. The method for preparing copper-clad aluminum alloy composite strip according to claim 1, characterized in that: The zirconium-chromium-copper alloy strip is composed of the following components by mass percentage: zirconium 0.15~0.20%, chromium 0.6~0.8%, and the balance being copper.

5. The method for preparing copper-clad aluminum alloy composite strip according to claim 1 or 4, characterized in that: The zirconium-cerium-aluminum alloy liquid is composed of the following components by mass percentage: zirconium 0.15~0.2%, cerium 0.02%, and the balance being aluminum.

6. The method for preparing copper-clad aluminum alloy composite strip according to claim 1, characterized in that: The molten zirconium-cerium-aluminum alloy flows out through the distribution casting nozzle and simultaneously contacts two zirconium-chromium-copper alloy plates and strips; the height of the molten zirconium-cerium-aluminum alloy at the outlet of the distribution casting nozzle is 10-16mm.

7. The method for preparing copper-clad aluminum alloy composite strip according to claim 1 or 6, characterized in that: The length of the casting and rolling zone is 50~80mm.

8. The method for preparing copper-clad aluminum alloy composite strip according to claim 1, 2, 4, or 6, characterized in that: The casting and rolling process is a horizontal continuous casting and rolling process.

9. The method for preparing copper-clad aluminum alloy composite strip according to claim 1, 2, 4, or 6, characterized in that: The thickness of the zirconium-chromium-copper alloy strip is 1.5 to 2 mm.

10. A copper-clad aluminum alloy composite strip prepared by the method described in any one of claims 1 to 9.

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