Aluminum alloy multilayer composite board and preparation method and application thereof

Abstract

The invention provides an aluminum alloy multilayer composite board and a preparation method and application thereof. The aluminum alloy multi-layer composite board comprises a first layer, a second layer, a third layer and a fourth layer which are sequentially overlapped, wherein the first layer and the third layer are both made of 3XXX series aluminum alloy, the second layer is made of 6XXX series aluminum alloy, the fourth layer is made of 4XXX series aluminum alloy, and the 6XXX series aluminum alloy comprises the following elements of Si element, Mg element, Cu element, Zn element, Mn element, Zr element, Cr element, Ti element, Fe element and Al element in percentage by mass. And the 6XXX series aluminum alloy is arranged between the 3XXX series aluminum alloys, so that high-temperature volatilization of Mg elements in the 6XXX series aluminum alloys can be prevented, and the high-temperature resistance of the aluminum alloy multilayer composite plate can be improved. The aluminum alloy multi-layer composite plate not only has higher yield strength, tensile strength and elongation, but also has lower cost.

Description

Technical Field

[0001] The present invention relates to the technical field of aluminum alloys, and in particular to an aluminum alloy multilayer composite plate and a preparation method and application thereof. Background Art

[0002] A large amount of heat is generated during the charging and discharging process of the power battery of new energy vehicles. Excessive temperature will affect the performance, life and safety of the battery. Liquid cooling plates can efficiently remove the heat generated by the battery and keep the battery working within a suitable temperature range. With the continuous expansion of the new energy vehicle market and the increasing requirements of consumers for driving range and battery safety, the application proportion of liquid cooling plates in the thermal management of new energy vehicle batteries will continue to increase; in addition, with the rapid development of the energy storage industry, the heat generated by the charging and discharging of the energy storage system battery needs to be transferred immediately to keep the battery system running within a safe temperature, which also puts higher demands on liquid cooling plates.

[0003] Traditional brazing plate composite plates used for heat exchange are mainly 4XXX / 3XXX composite plates, among which 3XXX series aluminum alloys are Al-Mn alloys with low strength, and 3003 alloys and their modified alloys are mainly used. 4XXX series aluminum alloys are Al-Si alloys, which are used as solder and completely melt during brazing at temperatures above 600°C to fill the gaps in the joints and play a connecting role. The 4XXX / 3XXX composite plates have poor anti-collapse ability during high-temperature brazing and low yield strength of only about 50MPa. The actual produced liquid cooling plates have insufficient strength and rigidity, making it difficult to support the weight of the battery module, and require supporting steel bracket structure reinforcement, resulting in a significant increase in weight, and the lightweight effect is difficult to meet industry needs. Summary of the invention

[0004] The main purpose of the present invention is to provide an aluminum alloy multilayer composite plate and a preparation method and application thereof, so as to solve the problem of low yield strength of the aluminum alloy multilayer composite plate in the prior art.

[0005] In order to achieve the above-mentioned object, according to one aspect of the present invention, there is provided an aluminum alloy multilayer composite plate, the aluminum alloy multilayer composite plate comprising a first layer, a second layer, a third layer and a fourth layer stacked in sequence; wherein the first layer and the third layer are both 3XXX series aluminum alloys, the second layer is 6XXX series aluminum alloys, and the fourth layer is 4XXX series aluminum alloys, and the 6XXX series aluminum alloys include the following elements by mass percentage: the content of Si element is 0.3-0.7%, the content of Mg element is 0.6-0.9%, and the content of Cu element is 0.1 ~0.3%, the content of Zn element is 0.05~0.3%, the content of Mn element is 0.01~0.15%, the content of Zr element is 0.01~0.08%, the content of Cr element is 0.001~0.1%, the content of Ti element is 0.001~0.04%, the content of Fe element is 0.05~0.6%, and the content of Si element is lower than that of Mg element, the total content of unavoidable impurities is ≤0.15wt%, the content of single impurity is lower than 0.05wt%, and the balance is Al element.

[0006] Furthermore, the 6XXX series aluminum alloy includes the following elements, in percentage by mass: 0.45-0.7% Si, 0.8-0.9% Mg, 0.15-0.25% Cu, 0.15-0.25% Zn, 0.02-0.15% Mn, 0.04-0.08% Zr, 0.01-0.1% Cr, 0.03-0.04% Ti, 0.25-0.6% Fe, and the Si content is lower than the Mg content. The total content of unavoidable impurities is ≤0.15wt%, the content of a single impurity is lower than 0.05wt%, and the balance is Al.

[0007] Furthermore, the mass ratio of the above-mentioned Si element to the Mg element is (0.50~0.76):1; and / or the mass ratio of the Cu element to the Zn element is (1~2):1; and / or the mass ratio of the Mn element, the Zr element and the Cr element is 1:(0.27~4):(0.5~0.7); and / or the 3XXX series aluminum alloy is selected from any one or more of the 3003 alloy, the 3004 alloy and the 3105 alloy; and / or the 4XXX series aluminum alloy is selected from any one or more of the 4004 alloy, the 4045 alloy, the 4047 alloy, the 4104 alloy, the 4147 alloy and the 4343 alloy.

[0008] Furthermore, the thickness of the above-mentioned aluminum alloy multilayer composite plate is 0.5~2.0mm; and / or the average grain size of the aluminum alloy multilayer composite plate is 80~90μm; and / or the yield strength of the aluminum alloy multilayer composite plate is ≥156MPa; and / or the tensile strength of the aluminum alloy multilayer composite plate is ≥205MPa; and / or the elongation of the aluminum alloy multilayer composite plate is ≥14.3%.

[0009] According to another aspect of the present invention, there is provided a method for preparing the aforementioned aluminum alloy multilayer composite plate, the preparation method comprising: step S1, sequentially slitting and performing a first hot rolling treatment on a 3XXX series aluminum alloy ingot to obtain a first layer of hot-rolled plate and a third layer of hot-rolled plate, milling a 6XXX series aluminum alloy ingot to obtain a second layer of cast plate, and performing a third hot rolling treatment on a 4XXX series aluminum alloy ingot to obtain a fourth layer of hot-rolled plate; step S2, sequentially stacking the first layer of hot-rolled plate, the second layer of cast plate, the third layer of hot-rolled plate and the fourth layer of hot-rolled plate, and sequentially performing welding and fixing, a second hot rolling treatment, a cold rolling treatment and an annealing treatment to obtain an aluminum alloy multilayer composite plate.

[0010] Furthermore, the thickness ratio of the first layer of hot-rolled plate, the second layer of cast plate, the third layer of hot-rolled plate and the fourth layer of hot-rolled plate is (90-100): (400-410): (66-76): (39-49).

[0011] Furthermore, the temperature of the second hot rolling treatment is 480-490°C; and / or the thickness of the plate after the second hot rolling treatment is 3.0-6.0 mm; and / or the temperature of the annealing treatment is 380-440°C; and / or the holding time of the annealing treatment is 4-6 h.

[0012] Furthermore, the above step S2 also includes sequentially performing brazing treatment and aging treatment on the plate obtained after annealing treatment to obtain an aluminum alloy multilayer composite plate.

[0013] Furthermore, the temperature of the brazing treatment is 600-625°C; and / or the holding time of the brazing treatment is 20-60min; and / or the temperature of the aging treatment is 200-240°C; and / or the holding time of the aging treatment is 20-40min.

[0014] According to another aspect of the present invention, there is provided application of the aforementioned aluminum alloy multilayer composite plate on a liquid cooling plate.

[0015] By applying the technical solution of the present invention, the present application arranges the 6XXX series aluminum alloy between the 3XXX series aluminum alloy, which helps to prevent the high temperature volatilization of the Mg element in the 6XXX series aluminum alloy, thereby helping to improve the high temperature resistance of the aluminum alloy multilayer composite plate. In addition, the 3XXX series aluminum alloy has a high corrosion resistance, and the 6XXX series aluminum alloy is arranged between the 3XXX series aluminum alloy, which helps to improve the corrosion resistance of the aluminum alloy multilayer composite plate. The effect of the 4XXX series aluminum alloy enables the aluminum alloy multilayer composite plate to be brazed with other aluminum alloy plates. Controlling the content of the Mg element and the Si element in the 6XXX series aluminum alloy within the above range, and controlling the content of the Si element to be lower than the content of the Mg element, helps to promote the formation of a strengthening phase between the Mg element and the Si element, thereby helping to improve the yield strength, tensile strength and elongation of the aluminum alloy multilayer composite plate. Controlling the content of the Cu element and the Zn element in the 6XXX series aluminum alloy within the above range helps to promote the formation of a strengthening phase between the Cu element and the Zn element and the aluminum element, thereby helping to further improve the yield strength, tensile strength and elongation of the aluminum alloy multilayer composite plate. The presence of Mn element, Zr element and Cr element helps to refine the grains, and controlling the content of Mn element, Zr element and Cr element within the above range helps to cooperate with other elements in 6XXX series aluminum alloy, thereby helping to further refine the grains, and then helping to improve the yield strength, tensile strength and elongation of the aluminum alloy multilayer composite plate. In addition, the present application can have a higher iron content, thereby helping to reduce the production cost of the aluminum alloy multilayer composite plate. Therefore, the aluminum alloy multilayer composite plate of the present application not only has higher yield strength, tensile strength and elongation, but also has lower cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0017] Figure 1 The schematic diagram of the structure of the aluminum alloy multilayer composite plate in Example 1 of the present application is shown;

[0018] Figure 2 The metallographic structure diagram of the aluminum alloy multilayer composite plate in Example 1 of the present application is shown;

[0019] Figure 3 A schematic diagram of the liquid cooling plate structure of the present application is shown.

[0020] The above drawings include the following reference numerals:

[0021] 1. First layer; 2. Second layer; 3. Third layer; 4. Fourth layer; 5. Cover plate; 6. Brazing plate. DETAILED DESCRIPTION

[0022] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0023] As analyzed in the background technology of this application, the aluminum alloy multilayer composite plate in the prior art has the problem of low yield strength. In order to solve the above problem, this application provides an aluminum alloy multilayer composite plate and a preparation method and application thereof.

[0024] In a typical embodiment of the present application, an aluminum alloy multilayer composite plate is provided, such as Figure 1 As shown, the aluminum alloy multilayer composite plate includes a first layer 1, a second layer 2, a third layer 3 and a fourth layer 4 stacked in sequence; wherein the first layer and the third layer are both 3XXX series aluminum alloys, the second layer is 6XXX series aluminum alloys, and the fourth layer is 4XXX series aluminum alloys. In terms of mass percentage, the 6XXX series aluminum alloy includes the following elements: the content of Si element is 0.3-0.7%, the content of Mg element is 0.6-0.9%, the content of Cu element is 0.1-0.3%, and the content of Zn element is The content of Mn element is 0.05~0.3%, the content of Zr element is 0.01~0.08%, the content of Cr element is 0.001~0.1%, the content of Ti element is 0.001~0.04%, the content of Fe element is 0.05~0.6%, and the content of Si element is lower than that of Mg element. The total content of inevitable impurities is ≤0.15wt%, the content of single impurity is lower than 0.05wt%, and the balance is Al element.

[0025] The present application arranges 6XXX series aluminum alloy between 3XXX series aluminum alloy, which helps to prevent the high temperature volatilization of Mg element in 6XXX series aluminum alloy, thereby helping to improve the high temperature resistance of aluminum alloy multilayer composite plate. And 3XXX series aluminum alloy has high corrosion resistance, and 6XXX series aluminum alloy is arranged between 3XXX series aluminum alloy, which helps to improve the corrosion resistance of aluminum alloy multilayer composite plate. The effect of 4XXX series aluminum alloy enables aluminum alloy multilayer composite plate to be brazed with other aluminum alloy plates. Controlling the content of Mg element and Si element in 6XXX series aluminum alloy within the above range, and controlling the content of Si element to be lower than the content of Mg element, helps to promote the formation of strengthening phase of Mg element and Si element, thereby helping to improve the yield strength, tensile strength and elongation of aluminum alloy multilayer composite plate. Controlling the content of Cu element and Zn element in 6XXX series aluminum alloy within the above range, helps to promote the formation of strengthening phase between Cu element and Zn element and aluminum element, thereby helping to further improve the yield strength, tensile strength and elongation of aluminum alloy multilayer composite plate. The presence of Mn element, Zr element and Cr element helps to refine the grains, and controlling the content of Mn element, Zr element and Cr element within the above range helps to cooperate with other elements in 6XXX series aluminum alloy, thereby helping to further refine the grains, and then helping to improve the yield strength, tensile strength and elongation of the aluminum alloy multilayer composite plate. In addition, the present application can have a higher iron content, thereby helping to reduce the production cost of the aluminum alloy multilayer composite plate. Therefore, the aluminum alloy multilayer composite plate of the present application not only has higher yield strength, tensile strength and elongation, but also has lower cost.

[0026] In order to further improve the yield strength, tensile strength and elongation of the aluminum alloy multi-layer composite plate, in one embodiment of the present application, the above-mentioned 6XXX series aluminum alloy preferably includes the following elements, by mass percentage: the content of Si element is 0.45~0.7%, the content of Mg element is 0.8~0.9%, the content of Cu element is 0.15~0.25%, the content of Zn element is 0.15~0.25%, the content of Mn element is 0.02~0.15%, the content of Zr element is 0.04~0.08%, the content of Cr element is 0.01~0.1%, the content of Ti element is 0.03~0.04%, the content of Fe element is 0.25~0.6%, and the content of Si element is lower than that of Mg element, the total content of inevitable impurities is ≤0.15wt%, the content of single impurity is less than 0.05wt%, and the balance is Al element.

[0027] In one embodiment of the present application, the mass ratio of the Si element to the Mg element is (0.50-0.76):1, specifically 0.50:1, 0.55:1, 0.60:1, 0.65:1, 0.70:1, 0.76:1 and a range between any two ratios; and / or the mass ratio of the Cu element to the Zn element is (1-2):1, specifically 1:1, 1.1:1, 1.2:1, 1.3:1, 1.4:1, 1.5:1, 1.6:1, 1.7:1, 1.8:1, 1.9:1, 2.0:1, 2.1:1, 2.2:1, 2.3:1, 2.4:1, 2.5:1, 2.6:1, 2.7:1, 2.8:1, 2.9:1, 2.1:1 8:1, 1.9:1, 2:1 and range values ​​between any two ratios; and / or, the mass ratio of Mn element, Zr element and Cr element is 1:(0.27-4):(0.5-0.7); and / or, the 3XXX series aluminum alloy is selected from any one or more of 3003 alloy, 3004 alloy and 3105 alloy; and / or, the 4XXX series aluminum alloy is selected from any one or more of 4004 alloy, 4045 alloy, 4047 alloy, 4104 alloy, 4147 alloy and 4343 alloy.

[0028] Controlling the mass ratio of Si element to Mg element within the above range helps to further improve the interaction between Si element and Mg element, thereby helping to further promote the formation of strengthening phase between Mg element and Si element, and further helping to improve the yield strength, tensile strength and elongation of the aluminum alloy multilayer composite plate. Controlling the mass ratio of Cu element to Zn element within the above range helps to further improve the interaction between Cu element and Zn element, thereby helping to further promote the formation of strengthening phase between Cu element and Zn element and aluminum element, and further helping to further improve the yield strength, tensile strength and elongation of the aluminum alloy multilayer composite plate. Controlling the mass ratio of Mn element, Zr element and Cr element within the above range helps to improve the interaction between Mn element, Zr element and Cr element, thereby helping to further refine the grains, and further helping to further improve the yield strength, tensile strength and elongation of the aluminum alloy multilayer composite plate.

[0029] In one embodiment of the present application, the mass ratio of the Ti element to the Fe element is (0.10~0.15):1, specifically 0.10:1, 0.11:1, 0.12:1, 0.13:1, 0.14:1, 0.15:1 and a range value between any two ratios.

[0030] The presence of Ti element helps to stabilize the precipitated phase in the material, reduces the aggregation of the precipitated phase during the aging treatment, and helps to improve its uniform distribution. The presence of Fe element helps to promote the stability of these precipitated phases, further improving the strength and hardness of the material. Controlling the mass ratio of Ti element to Fe element within the above range helps to optimize the distribution of precipitation strengthening phases, thereby helping to further improve the yield strength, tensile strength and elongation of the aluminum alloy multilayer composite plate.

[0031] In one embodiment of the present application, the thickness of the above-mentioned aluminum alloy multilayer composite plate is 0.5~2.0mm; and / or, the average grain size of the aluminum alloy multilayer composite plate is 80~90μm; and / or, the yield strength of the aluminum alloy multilayer composite plate is ≥156MPa; and / or, the tensile strength of the aluminum alloy multilayer composite plate is ≥205MPa; and / or, the elongation of the aluminum alloy multilayer composite plate is ≥14.3%; preferably, the yield strength of the aluminum alloy multilayer composite plate is 167~175MPa; and / or, the tensile strength of the aluminum alloy multilayer composite plate is 215~219MPa; and / or, the elongation of the aluminum alloy multilayer composite plate is 15.2~15.5%.

[0032] Controlling the thickness of the aluminum alloy multilayer composite plate within the above range helps to improve the stamping performance of the aluminum alloy multilayer composite plate, and controlling the average grain size of the aluminum alloy multilayer composite plate within the above range helps to further improve the yield strength, tensile strength and elongation of the aluminum alloy multilayer composite plate. The aluminum alloy multilayer composite plate having the above yield strength, tensile strength and elongation is more suitable for liquid cooling plates.

[0033] In a typical embodiment of the present application, a method for preparing the aforementioned aluminum alloy multilayer composite plate is provided, and the preparation method comprises: step S1, slitting and performing a first hot rolling treatment on a 3XXX series aluminum alloy ingot in sequence to obtain a first layer of hot-rolled plate and a third layer of hot-rolled plate, milling the 6XXX series aluminum alloy ingot to obtain a second layer of cast plate, and performing a third hot rolling treatment on a 4XXX series aluminum alloy ingot to obtain a fourth layer of hot-rolled plate; step S2, sequentially stacking the first layer of hot-rolled plate, the second layer of cast plate, the third layer of hot-rolled plate and the fourth layer of hot-rolled plate, and then sequentially welding and fixing, performing a second hot rolling treatment, a cold rolling treatment and an annealing treatment to obtain an aluminum alloy multilayer composite plate.

[0034] In step S1, 3XXX series aluminum alloy ingots, 6XXX series aluminum alloy ingots and 4XXX series aluminum alloy ingots are pre-treated to obtain the first layer of hot rolled plate, the second layer of cast plate, the third layer of hot rolled plate and the fourth layer of hot rolled plate of suitable specifications. In step S2, the first layer of hot rolled plate, the second layer of cast plate, the third layer of hot rolled plate and the fourth layer of hot rolled plate are stacked and welded and fixed in sequence, which helps to closely combine the first layer of hot rolled plate, the second layer of cast plate, the third layer of hot rolled plate and the fourth layer of hot rolled plate to form a firm interlayer interface. The second hot rolling treatment helps to promote the uniform distribution of alloy elements in the aluminum matrix, and the grains are refined at the same time, which is conducive to the formation of a microstructure that improves the strength and ductility of the material. Cold rolling treatment helps to accurately control the thickness of the aluminum alloy multilayer composite plate and improve the surface finish of the aluminum alloy multilayer composite plate. Annealing treatment helps to eliminate the work hardening produced during the cold rolling process and restore the plasticity of the material, thereby helping to reduce the cracking of the aluminum alloy multilayer composite plate during the stamping process.

[0035] In one embodiment of the present application, the thickness ratio of the first layer of hot-rolled plate, the second layer of cast plate, the third layer of hot-rolled plate and the fourth layer of hot-rolled plate is (90~100):(400~410):(66~76):(39~49).

[0036] The 6XXX series aluminum alloy of the second layer of cast plate provides corresponding strength for the composite plate. The 3XXX series aluminum alloy in the first layer of hot-rolled plate and the third layer of hot-rolled plate acts as a protective layer, which helps to reduce the high-temperature volatilization of the Mg element in the second layer of cast plate and helps to improve the performance stability of the composite plate. The 4XXX series aluminum alloy of the fourth layer of hot-rolled plate acts as a solder layer, which helps to improve the bonding force between the composite plate and other aluminum alloy plates. Controlling the thickness ratio of the first layer of hot-rolled plate, the second layer of cast plate, the third layer of hot-rolled plate and the fourth layer of hot-rolled plate within the above range helps to give full play to the interaction between the components, thereby helping to improve the stamping performance of the aluminum alloy multilayer composite plate while improving the yield strength, tensile strength and elongation of the aluminum alloy multilayer composite plate.

[0037] In one embodiment of the present application, the temperature of the second hot rolling treatment is 480~490°C; and / or the thickness of the plate after the second hot rolling treatment is 3.0~6.0mm; and / or the temperature of the annealing treatment is 380~440°C; and / or the holding time of the annealing treatment is 4~6h.

[0038] Controlling the temperature of the second hot rolling treatment within the above range helps to promote the uniform distribution of alloy elements and reduce abnormal grain growth while ensuring the plasticity of the material, thereby helping to optimize the microstructure of the composite plate and enhance the interlayer bonding strength. Controlling the thickness of the plate after the second hot rolling treatment within the above range helps to provide a good foundation for the subsequent cold rolling treatment, improve the deformation uniformity of the material during the cold rolling process, and reduce the risk of cracking or delamination. Controlling the temperature and holding time of the annealing treatment within the above range helps to eliminate work hardening during the cold rolling process and reduce the risk of alloy element decomposition and performance degradation caused by high temperature.

[0039] In one embodiment of the present application, the above step S2 further includes sequentially performing brazing treatment and aging treatment on the plate obtained after the annealing treatment to obtain an aluminum alloy multilayer composite plate.

[0040] Brazing treatment helps to enhance the bonding strength between the layers of the composite plate and improve the stability and bearing capacity of the overall structure. Aging treatment helps to improve the uniformity of the distribution of precipitated phases in the alloy, thereby helping to improve the yield strength, tensile strength and elongation of the material.

[0041] In one embodiment of the present application, the temperature of the above-mentioned brazing treatment is 600~625℃; and / or, the holding time of the brazing treatment is 20~60min; and / or, the temperature of the aging treatment is 200~240℃; and / or, the holding time of the aging treatment is 20~40min.

[0042] Controlling the brazing temperature and holding time within the above ranges helps reduce the risk of overburning of the 6XXX aluminum alloy during the brazing process and helps prevent damage to the mechanical properties of the 6XXX aluminum alloy. Controlling the aging temperature and holding time within the above ranges helps promote the uniform distribution of precipitated phases in the 6XXX aluminum alloy, which can significantly enhance the hardness and strength of the material without excessively sacrificing its ductility.

[0043] In a typical embodiment of the present application, there is provided application of the aforementioned aluminum alloy multi-layer composite plate on a liquid cooling plate.

[0044] The aluminum alloy multilayer composite plate of the present application can be used to manufacture liquid cooling plates in the field of thermal management of new energy vehicle batteries and liquid cooling plates in the field of energy storage systems, such as Figure 3 The liquid cooling plate shown includes a cover plate 5 and a brazing plate 6. The brazing plate 6 is the aluminum alloy multilayer composite plate of the present application obtained by stamping.

[0045] The beneficial effects of the present application will be further illustrated below in conjunction with embodiments.

[0046] Example 1

[0047] Measured in percentage by mass, the element ratio of 6XXX series alloy ingots is: 0.45% Si element, 0.82% Mg element, 0.25% Cu element, 0.25% Zn element, 0.15% Mn element, 0.04% Zr element, 0.1% Cr element, 0.03% Ti element, 0.25% Fe element, and the balance is aluminum element.

[0048] The 3003 alloy ingot is sequentially cut and subjected to the first hot rolling treatment to obtain a first layer of hot rolled plate with a thickness of 90 mm and a third layer of hot rolled plate with a thickness of 66 mm. The above 6XXX series alloy ingot is milled to obtain a second layer of cast plate with a thickness of 410 mm. The 4045 alloy ingot is subjected to the third hot rolling treatment to obtain a fourth layer of hot rolled plate with a thickness of 49 mm. The surface is then cleaned. The first layer of hot rolled plate, the second layer of cast plate, the third layer of hot rolled plate and the fourth layer of hot rolled plate are sequentially stacked, and the edges are fixed by argon arc welding. Then, the cold rolled plate is subjected to composite hot rolling at 480°C to 6.0 mm, and then cold rolled to a cold rolled plate with a thickness of 1.2 mm. The cold rolled plate is subjected to annealing treatment at 380°C for 6 hours, and then brazed at 620°C for 20 minutes. After cooling, an aging treatment is performed at 220°C for 40 minutes to obtain an aluminum alloy multilayer composite plate. Figure 1 As shown, it includes a first layer 1, a second layer 2, a third layer 3 and a fourth layer 4 stacked in sequence.

[0049] Example 2

[0050] The difference from Example 1 is that the content of Si element is 0.68%, and the content of Mg element is 0.89%, and finally an aluminum alloy multilayer composite plate is obtained.

[0051] Example 3

[0052] The difference from Example 1 is that the content of Si element is 0.31%, and the content of Mg element is 0.62%, and finally an aluminum alloy multilayer composite plate is obtained.

[0053] Example 4

[0054] The difference from Example 1 is that the content of Cu element is 0.15%, and the content of Zn element is 0.15%, and finally an aluminum alloy multilayer composite plate is obtained.

[0055] Example 5

[0056] The difference from Example 1 is that the content of Mn element is 0.02%, the content of Zr element is 0.08%, and the content of Cr element is 0.01%, and finally an aluminum alloy multilayer composite plate is obtained.

[0057] Example 6

[0058] The difference from Example 1 is that the content of Si element is 0.7%, and the content of Mg element is 0.9%, and finally an aluminum alloy multilayer composite plate is obtained.

[0059] Example 7

[0060] The difference from Example 1 is that the content of Cu element is 0.15%, and the content of Zn element is 0.25%, and finally an aluminum alloy multilayer composite plate is obtained.

[0061] Example 8

[0062] The difference from Example 1 is that the content of Mn element is 0.02%, the content of Zr element is 0.08%, and the content of Cr element is 0.1%, and finally an aluminum alloy multilayer composite plate is obtained.

[0063] Example 9

[0064] The difference from Example 1 is that the content of the Ti element is 0.03%, and the content of the Fe element is 0.6%, and finally an aluminum alloy multilayer composite plate is obtained.

[0065] Example 10

[0066] The difference from Example 1 is that the thickness of the first hot-rolled plate is 100 mm, the thickness of the second cast plate is 400 mm, the thickness of the third hot-rolled plate is 76 mm, and the thickness of the fourth hot-rolled plate is 39 mm, and finally an aluminum alloy multilayer composite plate is obtained.

[0067] Embodiment 11

[0068] The difference from Example 1 is that the thickness of the first hot-rolled plate is 110 mm, the thickness of the second cast plate is 390 mm, the thickness of the third hot-rolled plate is 86 mm, and the thickness of the fourth hot-rolled plate is 29 mm, and finally an aluminum alloy multilayer composite plate is obtained.

[0069] Example 12

[0070] The difference from Example 1 is that the annealing temperature is 440° C., the annealing holding time is 4 hours, and finally an aluminum alloy multilayer composite plate is obtained.

[0071] Example 13

[0072] The difference from Example 1 is that the annealing temperature is 450° C., the annealing holding time is 3 h, and finally an aluminum alloy multilayer composite plate is obtained.

[0073] Embodiment 14

[0074] The difference from Example 1 is that the temperature of the brazing treatment is 600° C., the holding time is 60 min, the temperature of the aging treatment is 240° C., and the holding time of the aging treatment is 20 min, and finally an aluminum alloy multilayer composite plate is obtained.

[0075] Embodiment 15

[0076] The difference from Example 1 is that the brazing treatment temperature is 550° C., the holding time is 90 min, the aging treatment temperature is 150° C., and the holding time is 50 min, and finally an aluminum alloy multilayer composite plate is obtained.

[0077] Comparative Example 1

[0078] The difference from Example 1 is that the annealing treatment, the brazing treatment and the aging treatment are eliminated, and the plate after the cold rolling treatment is directly used as the aluminum alloy multilayer composite plate.

[0079] Comparative Example 2

[0080] The difference from Example 1 is that the content of Si element is 0.85%, and the content of Mg element is 0.65%, and finally an aluminum alloy multilayer composite plate is obtained.

[0081] Comparative Example 3

[0082] The difference from Example 1 is that the addition of Mn element, Zr element and Cr element in the 6XXX series alloy ingot is cancelled, and finally an aluminum alloy multilayer composite plate is obtained.

[0083] Comparative Example 4

[0084] The difference from Example 1 is that the addition of Cu and Zn elements in the 6XXX series alloy ingot is eliminated, and finally an aluminum alloy multilayer composite plate is obtained.

[0085] The aluminum alloy multilayer composite plates prepared in the examples and comparative examples were tested for average grain size, yield strength, tensile strength and elongation, and the stamping conditions and overburning of the aluminum alloy multilayer composite plates were observed. The test results are shown in Table 1.

[0086] Table 1

[0087]

[0088] Figure 2 The metallographic structure diagram of the aluminum alloy multilayer composite plate in Example 1 of the present application is as follows: Figure 2 It can be seen that the metallographic structure is distributed more evenly.

[0089] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0090] The present application arranges 6XXX series aluminum alloy between 3XXX series aluminum alloy, which helps to prevent the high temperature volatilization of Mg element in 6XXX series aluminum alloy, thereby helping to improve the high temperature resistance of aluminum alloy multilayer composite plate. And 3XXX series aluminum alloy has high corrosion resistance, and 6XXX series aluminum alloy is arranged between 3XXX series aluminum alloy, which helps to improve the corrosion resistance of aluminum alloy multilayer composite plate. The effect of 4XXX series aluminum alloy enables aluminum alloy multilayer composite plate to be brazed with other aluminum alloy plates. Controlling the content of Mg element and Si element in 6XXX series aluminum alloy within the above range, and controlling the content of Si element to be lower than the content of Mg element, helps to promote the formation of strengthening phase of Mg element and Si element, thereby helping to improve the yield strength, tensile strength and elongation of aluminum alloy multilayer composite plate. Controlling the content of Cu element and Zn element in 6XXX series aluminum alloy within the above range, helps to promote the formation of strengthening phase between Cu element and Zn element and aluminum element, thereby helping to further improve the yield strength, tensile strength and elongation of aluminum alloy multilayer composite plate. The presence of Mn element, Zr element and Cr element helps to refine the grains, and controlling the content of Mn element, Zr element and Cr element within the above range helps to cooperate with other elements in 6XXX series aluminum alloy, thereby helping to further refine the grains, and then helping to improve the yield strength, tensile strength and elongation of the aluminum alloy multilayer composite plate. In addition, the present application can have a higher iron content, thereby helping to reduce the production cost of the aluminum alloy multilayer composite plate. Therefore, the aluminum alloy multilayer composite plate of the present application not only has higher yield strength, tensile strength and elongation, but also has lower cost.

[0091] The above are only embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An aluminum alloy multilayer composite plate, characterized in that: The aluminum alloy multilayer composite plate comprises a first layer, a second layer, a third layer and a fourth layer stacked in sequence; wherein the first layer and the third layer are both 3XXX series aluminum alloys, the second layer is 6XXX series aluminum alloys, and the fourth layer is 4XXX series aluminum alloys, The 6XXX series aluminum alloy includes the following elements in percentage by mass: 0.3-0.7% Si, 0.6-0.9% Mg, 0.1-0.3% Cu, 0.05-0.3% Zn, 0.01-0.15% Mn, 0.01-0.08% Zr, 0.001-0.1% Cr, 0.001-0.1%, 0.001-0.04% Ti, 0.05-0.6% Fe, the Si content is lower than the Mg content, the total content of unavoidable impurities is ≤0.15wt%, the content of a single impurity is lower than 0.05wt%, and the balance is Al.

2. The aluminum alloy multilayer composite plate according to claim 1, characterized in that: The 6XXX series aluminum alloy includes the following elements in percentage by mass: the Si element content is 0.45-0.7%, the Mg element content is 0.8-0.9%, the Cu element content is 0.15-0.25%, the Zn element content is 0.15-0.25%, the Mn element content is 0.02-0.15%, the Zr element content is 0.04-0.08%, the Cr element content is 0.01-0.1%, the Ti element content is 0.03-0.04%, the Fe element content is 0.25-0.6%, and the Si element content is lower than the Mg element content, the total content of inevitable impurities is ≤0.15wt%, the content of a single impurity is lower than 0.05wt%, and the balance is Al element.

3. The aluminum alloy multilayer composite plate according to claim 2, characterized in that: The mass ratio of the Si element to the Mg element is (0.50-0.76):1; and / or the mass ratio of the Cu element to the Zn element is (1-2):1; and / or the mass ratio of the Mn element, the Zr element and the Cr element is 1:(0.27-4):(0.5-0.7); And / or, the 3XXX series aluminum alloy is selected from any one or more of 3003 alloy, 3004 alloy and 3105 alloy; And / or, the 4XXX series aluminum alloy is selected from any one or more of 4004 alloy, 4045 alloy, 4047 alloy, 4104 alloy, 4147 alloy and 4343 alloy.

4. The aluminum alloy multilayer composite plate according to any one of claims 1 to 3, characterized in that: The thickness of the aluminum alloy multilayer composite plate is 0.5~2.0mm; and / or the average grain size of the aluminum alloy multilayer composite plate is 80~90μm; and / or the yield strength of the aluminum alloy multilayer composite plate is ≥156MPa; and / or the tensile strength of the aluminum alloy multilayer composite plate is ≥205MPa; and / or the elongation of the aluminum alloy multilayer composite plate is ≥14.3%.

5. A method for preparing the aluminum alloy multi-layer composite plate according to any one of claims 1 to 4, characterized in that: The preparation method comprises: Step S1, sequentially performing slitting and a first hot rolling treatment on a 3XXX series aluminum alloy ingot to obtain a first layer of hot rolled plate and a third layer of hot rolled plate, performing surface milling on a 6XXX series aluminum alloy ingot to obtain a second layer of cast plate, and performing a third hot rolling treatment on a 4XXX series aluminum alloy ingot to obtain a fourth layer of hot rolled plate; Step S2, stacking the first layer of hot-rolled plate, the second layer of cast plate, the third layer of hot-rolled plate and the fourth layer of hot-rolled plate in sequence, and then welding and fixing them, performing a second hot rolling treatment, a cold rolling treatment and an annealing treatment in sequence to obtain the aluminum alloy multilayer composite plate.

6. The preparation method according to claim 5, characterized in that: The thickness ratio of the first layer of hot-rolled plate, the second layer of cast plate, the third layer of hot-rolled plate and the fourth layer of hot-rolled plate is (90-100): (400-410): (66-76): (39-49).

7. The preparation method according to claim 6, characterized in that: The temperature of the second hot rolling treatment is 480-490°C; and / or the thickness of the plate after the second hot rolling treatment is 3.0-6.0 mm; and / or the temperature of the annealing treatment is 380-440°C; and / or the holding time of the annealing treatment is 4-6 hours.

8. The preparation method according to any one of claims 5 to 7, characterized in that: The step S2 further comprises sequentially performing brazing treatment and aging treatment on the plate obtained after the annealing treatment to obtain the aluminum alloy multilayer composite plate.

9. The preparation method according to claim 8, characterized in that: The temperature of the brazing treatment is 600-625° C.; and / or, the holding time of the brazing treatment is 20-60 min; and / or, the temperature of the aging treatment is 200-240° C.; and / or, the holding time of the aging treatment is 20-40 min.

10. Use of the aluminum alloy multilayer composite plate according to any one of claims 1 to 4 in a liquid cooling plate.

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