Multi-layer high-strength weldable composite plate for liquid cooling plate as well as preparation method and application of multi-layer high-strength weldable composite plate

Abstract

The invention discloses a multi-layer high-strength weldable composite plate for a liquid cooling plate and a preparation method and application of the multi-layer high-strength weldable composite plate, and relates to the field of manufacturing methods of multi-layer high-strength weldable composite plates. The technical problem that an existing 4343 / 3003 composite board is low in strength after high-temperature brazing is solved. The multi-layer high-strength weldable composite board is a four-layer high-strength weldable composite board or a three-layer high-strength weldable composite board. The preparation method comprises the following steps: 1, pretreating an Al-Si-Cu-Mg-Mn-Zr alloy ingot blank; 2, preparing a hot-rolled plate blank; and 3, cold rolling, annealing, flattening and shearing. The prepared multi-layer high-strength weldable composite plate for the liquid cooling plate not only meets the design and material selection requirements of the liquid cooling plate of a brazed battery, but also is more beneficial to popularization and application of the liquid cooling plate. The multi-layer high-strength weldable composite plate prepared by the invention is used for a composite plate for a battery liquid cooling plate.

Description

Technical Field

[0001] The present invention relates to a multi-layer high-strength weldable composite plate for a liquid cooling plate, a preparation method thereof, and an application thereof. Background Art

[0002] The internal of an automotive thermal management system includes components such as a condenser, an evaporator, a radiator, an intercooler, a heater, and an oil cooler. New energy vehicles will have more heat transfer requirements due to the addition of the three-electric system. Among them, the liquid cooling plate, as an important heat dissipation component, belongs to the battery thermal management system. At present, many vehicle manufacturers have embraced the liquid cooling technology solution, and typical domestic and foreign vehicle models have also adopted the liquid cooling technology. Currently, the common panel for the battery liquid cooling plate at home and abroad is 3003 alloy, and the flow channel is a 4343 / 3003 composite plate. The strength before and after welding is generally low. Among them, the tensile strength before brazing is 95 - 135 MPa, the yield strength ≥ 35 MPa, and the elongation is 15 - 23%. The tensile strength after brazing is 105 - 120 MPa, the yield strength is 40 - 55 MPa, and the elongation is 20 - 26%. With the continuous popularization and application of new energy vehicles, higher and higher requirements are put forward for the comprehensive performance of the battery liquid cooling plate, including mechanical properties. Due to the low strength of the ordinary 4343 / 3003 composite plate, it is difficult to meet the user's requirements. In order to solve the problem of low strength of the composite plate for the battery liquid cooling plate after brazing, it is now necessary to develop a new type of high-strength brazable plate for the liquid cooling plate to replace the conventional 4343 / 3003 composite plate and 3003 alloy single plate, improve the strength of the composite plate after brazing, and meet the user's usage requirements. Summary of the Invention

[0003] The purpose of the present invention is to solve the problem of low strength of the composite plate for the battery liquid cooling plate after existing brazing, and a multi-layer high-strength weldable composite plate for a liquid cooling plate, a preparation method thereof, and an application thereof are proposed.

[0004] A multi-layer high-strength weldable composite plate for a liquid cooling plate of the present invention is a four-layer high-strength weldable composite plate or a three-layer high-strength weldable composite plate; wherein the four-layer high-strength weldable composite plate is rolled from a 4045 alloy slab, a 3003 alloy slab, and an Al-Si-Cu-Mg-Mn-Zr alloy ingot blank in the order of 4045 / 3003 / Al-Si-Cu-Mg-Mn-Zr / 3003; the three-layer high-strength weldable composite plate is rolled from a 3003 alloy slab and an Al-Si-Cu-Mg-Mn-Zr alloy ingot blank in the order of 3003 / Al-Si-Cu-Mg-Mn-Zr / 3003.

[0005] The preparation method of the four-layer high-strength weldable composite plate is as follows:

[0006] 1. Saw cut, face milling, and homogenization treatment are performed on the core material Al-Si-Cu-Mg-Mn-Zr alloy ingot blank to obtain the treated Al-Si-Cu-Mg-Mn-Zr alloy ingot blank;

[0007] 2. The 4045 alloy slab, 3003 alloy slab, and the treated Al-Si-Cu-Mg-Mn-Zr alloy ingot blank are arranged in the order of 4045 / 3003 / Al-Si-Cu-Mg-Mn-Zr / 3003. The cladding ratios are controlled to be: 8±2%, 15±3%, 67±2%, and 10±2% in sequence. They are welded by riveting, then heated to a temperature of 450°C - 480°C, and rolled to obtain a four-layer hot-rolled slab;

[0008] 3. The four-layer hot-rolled slab is cold-rolled to the finished thickness, then subjected to finish annealing. The annealing temperature is 300°C - 380°C, and it is held for 2h - 3h. After being taken out of the furnace and air-cooled, it is leveled and sheared to obtain a four-layer high-strength weldable composite plate.

[0009] The preparation method of the three-layer high-strength weldable composite plate is as follows:

[0010] 1. Saw cut, face milling, and homogenization treatment are performed on the core material Al-Si-Cu-Mg-Mn-Zr alloy ingot blank to obtain the treated Al-Si-Cu-Mg-Mn-Zr alloy ingot blank;

[0011] 2. The 3003 alloy slab and the treated Al-Si-Cu-Mg-Mn-Zr alloy ingot blank are arranged in the order of 3003 / Al-Si-Cu-Mg-Mn-Zr / 3003. The cladding ratios are controlled to be: 18±3%, 72±3%, and 10±2% in sequence. They are welded by riveting, then heated to a temperature of 450°C - 480°C, and rolled to obtain a three-layer hot-rolled slab;

[0012] 3. The three-layer hot-rolled slab is cold-rolled to the finished thickness, then subjected to finish annealing. The annealing temperature is 300°C - 380°C, and it is held for 2h - 3h. After being taken out of the furnace and air-cooled, it is leveled and sheared to obtain a three-layer high-strength weldable composite plate.

[0013] The multi-layer high-strength weldable composite plate prepared by the present invention is used for the battery liquid cooling plate.

[0014] In the present invention, a multi-layer high-strength weldable composite plate for a liquid cooling plate has an outer layer of 4045 alloy and 3003 alloy, a middle layer of 3003 alloy, and an innermost layer of Al-Si-Cu-Mg-Mn-Zr alloy. The functions of each layer of alloy are as follows: The 4045 alloy mainly plays a welding role; the middle layer of 3003 alloy plays an isolation role to prevent the volatilization of magnesium elements in the Al-Si-Cu-Mg-Mn-Zr alloy from reacting with the furnace protective gas nitrogen, and at the same time prevent the diffusion of Si elements in the 4045 alloy into the matrix of the innermost layer of Al-Si-Cu-Mg-Mn-Zr alloy, which affects the strength of the overall composite material; the outer layer of 3003 alloy plays an anti-corrosion role; the innermost layer of Al-Si-Cu-Mg-Mn-Zr alloy plays a role in strengthening the strength of the composite plate through age hardening.

[0015] The beneficial effects of the present invention are as follows:

[0016] Using the composite plate for a battery liquid cooling plate with high strength, high performance, and age hardening in the present invention, while ensuring that all performances meet the requirements, the tensile strength of the four-layer composite plate prepared by the present invention before brazing is 100-140 MPa, the yield strength is 50-65 MPa, and the elongation is 25%-31%; the tensile strength of the three-layer composite plate before brazing is 110-140 MPa, the yield strength is 50-67 MPa, and the elongation is 25%-31%. After artificial aging treatment after brazing under the same brazing system for the three-layer and four-layer composite plates, the tensile strength is ≥200 MPa, the yield strength is ≥150 MPa, and the elongation is ≥12%. Compared with the mechanical properties of the commonly used 4343 / 3003 in the current market, the strength before brazing is increased by about 13%, and the strength after brazing is increased by more than 84%. This makes these two types of composite plates for liquid cooling plates not only meet the design material selection requirements of the battery liquid cooling plate, but also be more conducive to the popularization and use of the battery liquid cooling plate. Description of the Drawings

[0017] Figure 1 Macrophotograph of the alloy ingot prepared in Example 1;

[0018] Figure 2 Macrophotograph of the multi-layer composite plate prepared in Example 1;

[0019] Figure 3 Welding and assembly application photograph of the battery liquid cooling plate prepared in Example 1. Detailed Embodiments

[0020] The technical solution of the present invention is not limited to the specific embodiments listed below, and also includes any combination between the specific embodiments.

[0021] Embodiment 1: The multi-layer high-strength weldable composite plate for a liquid cooling plate in this embodiment is a four-layer high-strength weldable composite plate or a three-layer high-strength weldable composite plate; among them, the four-layer high-strength weldable composite plate is formed by rolling a 4045 alloy slab, a 3003 alloy slab, and an Al-Si-Cu-Mg-Mn-Zr alloy ingot blank in the order of 4045 / 3003 / Al-Si-Cu-Mg-Mn-Zr / 3003; the three-layer high-strength weldable composite plate is formed by rolling a 3003 alloy slab and an Al-Si-Cu-Mg-Mn-Zr alloy ingot blank in the order of 3003 / Al-Si-Cu-Mg-Mn-Zr / 3003.

[0022] Embodiment 2: The multi-layer high-strength weldable composite plate for a liquid cooling plate in this embodiment is a four-layer high-strength weldable composite plate; the preparation method of the four-layer high-strength weldable composite plate is as follows:

[0023] 1. Saw, mill the surface, and homogenize the core Al-Si-Cu-Mg-Mn-Zr alloy ingot blank to obtain the treated Al-Si-Cu-Mg-Mn-Zr alloy ingot blank;

[0024] 2. Place the 4045 alloy slab, the 3003 alloy slab, and the treated Al-Si-Cu-Mg-Mn-Zr alloy ingot blank in the order of 4045 / 3003 / Al-Si-Cu-Mg-Mn-Zr / 3003, control the cladding ratios to be 8±2%, 15±3%, 67±2%, and 10±2% in sequence, weld them by riveting, then heat to a temperature of 450°C to 480°C, and perform rolling to obtain a four-layer hot-rolled slab;

[0025] 3. Cold roll the four-layer hot-rolled slab to the finished thickness, then perform finish annealing, the annealing temperature is 300°C to 380°C, hold for 2h to 3h, air-cool after leaving the furnace, and then level and shear to obtain a four-layer high-strength weldable composite plate.

[0026] In this embodiment, the brazing temperature of the four-layer high-strength weldable composite plate is 600 to 620°C, and the holding time is 5 to 20 minutes.

[0027] In this embodiment, the cladding ratio refers to the thickness ratio of each layer to the entire plate.

[0028] Embodiment 3: The multi-layer high-strength weldable composite plate for a liquid cooling plate in this embodiment is a three-layer high-strength weldable composite plate; the preparation method of the three-layer high-strength weldable composite plate is as follows:

[0029] 1. Saw, mill the surface, and homogenize the core Al-Si-Cu-Mg-Mn-Zr alloy ingot blank to obtain the treated Al-Si-Cu-Mg-Mn-Zr alloy ingot blank;

[0030] II. Place the 3003 alloy slab and the treated Al-Si-Cu-Mg-Mn-Zr alloy ingot blank in the order of 3003 / Al-Si-Cu-Mg-Mn-Zr / 3003, and control the cladding ratios to be 18±3%, 72±3% and 10±2% respectively. Weld them by riveting, then heat to 450°C - 480°C and perform rolling to obtain a three-layer hot-rolled slab.

[0031] III. Cold-roll the three-layer hot-rolled slab to the finished thickness, then perform finish annealing at an annealing temperature of 300°C - 380°C for 2h - 3h, air-cool after taking out of the furnace, and then level and shear to obtain a three-layer high-strength weldable composite plate.

[0032] In this embodiment, the brazing temperature of the three-layer high-strength weldable composite plate is 600 - 620°C and the holding time is 5 - 20 minutes.

[0033] In this embodiment, the cladding ratio refers to the thickness ratio of each layer to the entire plate.

[0034] Specific Embodiment 4: The difference between this embodiment and Embodiment 2 or 3 is that the preparation method of the Al-Si-Cu-Mg-Mn-Zr alloy ingot blank is as follows:

[0035] A. According to the mass percentages of each element: Si is 0.30% - 0.90%, Mg is 0.40% - 1.3%, Mn is 0.05% - 0.90%, Cu is 0.10% - 1.0%, Zn is 0.10% - 0.60%, Ti is 0.01% - 0.20%, Zr is 0.03% - 0.25%, Fe < 0.30%, and the balance is Al, weigh pure aluminum ingots, pure magnesium ingots, pure zinc ingots, aluminum-silicon master alloy, manganese agent, aluminum-copper master alloy, aluminum-titanium-boron wire grain refiner and aluminum-zirconium master alloy.

[0036] B. Add the pure aluminum ingots, pure zinc ingots, aluminum-silicon master alloy, manganese agent, aluminum-copper master alloy and aluminum-zirconium master alloy weighed in step A into a melting furnace, heat up to 740 - 760°C, melt and stir, remove slag, then add pure magnesium ingots, add No. 1 covering agent, melt for 15min - 30min, and then refine with Ar-Cl2 mixed gas until the hydrogen content in every 100 grams of aluminum alloy melt ≤ 0.25 mL, and let stand for 30min to obtain an aluminum alloy melt.

[0037] C. Filter the aluminum alloy melt obtained in step B through ceramic filter plates with 30ppi and 50ppi in sequence, then pour it into a mold, and at the same time insert the aluminum-titanium-boron wire grain refiner into the runner and uniformly melt it into the aluminum alloy melt; the insertion speed of the aluminum-titanium-boron wire grain refiner is 340mm / min.

[0038] D. Under the conditions of a temperature of 710 °C to 750 °C, a water pressure of 80 to 110 m 3 / h, and a speed of 30 to 60 mm / min, an Al-Si-Cu-Mg-Mn-Zr alloy ingot with a thickness of 440 mm, a width of 1450 mm, and a length of 1500 mm to 5500 mm is cast. The others are the same as in the second or third specific embodiment.

[0039] Specific embodiment five: The difference between this embodiment and the second or third specific embodiment is that: the No. 1 covering agent is the No. 1 flux, and the No. 1 flux is composed of 50% KCl, 26% NaCl, and 24% NaAlF6 by weight percentage; the dosage of the No. 1 covering agent is 0.4 to 0.6% of the total mass of the molten liquid in the melting furnace. The others are the same as in the second or third specific embodiment.

[0040] Specific embodiment six: The difference between this embodiment and the second or third specific embodiment is that: the casting method of the 4045 alloy slab is as follows:

[0041] Weigh industrial pure aluminum ingots, aluminum-silicon master alloy, and Al-Ti-B wire according to the mass percentage of each element as follows: Si is 9.0% to 11.0%, Fe < 0.80%, Cu < 0.30%, Mn < 0.05%, Mg < 0.05%, Zn < 0.10%, Ti < 0.20%, and the balance is aluminum; then add the industrial pure aluminum ingots and aluminum-silicon master alloy to the melting furnace, heat up to 740 to 760 °C to melt and stir, and after stirring, refining, and adjusting the composition, enter the holding furnace. After degassing and slag removal, the Al-Ti-B wire is added online at 720 °C to 740 °C for casting. The others are the same as in the second or third specific embodiment.

[0042] Specific embodiment seven: The difference between this embodiment and the second or third specific embodiment is that: the casting method of the 3003 alloy slab is specifically carried out according to the following steps:

[0043] Weigh industrial pure aluminum ingots, aluminum-copper master alloy, and aluminum-manganese master alloy according to the mass percentage of each element as follows: Si < 0.60%, Fe < 0.7%, Cu is 0.05% to 0.20%, Mn is 1.0% to 1.5%, Zn < 0.1%, and the balance is aluminum; add the industrial pure aluminum ingots, aluminum-copper master alloy, and aluminum-manganese master alloy to the melting furnace, heat up to 740 to 760 °C to melt and stir, and after stirring, refining, and adjusting the composition, enter the holding furnace. After degassing and slag removal, the Al-Ti-B wire is added online at 720 °C to 740 °C for casting. The others are the same as in the second or third specific embodiment.

[0044] In this embodiment, the dosage of the Al-Ti-B wire is controlled such that the input amount of the Ti element < 0.20%.

[0045] Embodiment VIII: Application of a multi-layer high-strength weldable composite plate for a liquid cooling plate in a battery liquid cooling plate.

[0046] Embodiment IX: The difference between this embodiment and Embodiment VIII is that the multi-layer high-strength weldable composite plate for a liquid cooling plate is a three-layer high-strength weldable composite plate and is applied to the panel of a battery liquid cooling plate. Others are the same as Embodiment VIII.

[0047] Embodiment X: The difference between this embodiment and Embodiment VIII or IX is that the multi-layer high-strength weldable composite plate for a liquid cooling plate is a four-layer high-strength weldable composite plate and is applied to the flow channel of a battery liquid cooling plate. Others are the same as Embodiment VIII or IX.

[0048] The following will give a detailed description of the embodiments of the present invention. The following embodiments are implemented on the premise of the technical solution of the present invention, and detailed implementation schemes and specific operation processes are given, but the protection scope of the present invention is not limited to the following embodiments.

[0049] Example 1:

[0050] The preparation method of a multi-layer high-strength weldable composite plate for a liquid cooling plate in this example is specifically carried out according to the following steps:

[0051] 1. Saw, mill the surface and homogenize the core material Al-Si-Cu-Mg-Mn-Zr alloy ingot blank;

[0052] 2. Place the 4045 alloy plate blank, 3003 alloy plate blank and the Al-Si-Cu-Mg-Mn-Zr alloy ingot blank processed in step 1 in the order of 4045 / 3003 / Al-Si-Cu-Mg-Mn-Zr / 3003, and control the cladding ratios to be: 8±2%, 15±3%, 67±2% and 10±2% in sequence. Weld them by riveting, then heat to a temperature of 450°C to 480°C and perform rolling to obtain a four-layer hot-rolled plate blank;

[0053] 3. Cold-roll the four-layer hot-rolled plate blank obtained in step 2 to the finished thickness, then perform finished annealing. The annealing temperature is 300°C to 380°C, hold for 2h to 3h, air-cool after taking out of the furnace, and then level and shear to obtain a four-layer high-strength weldable composite plate for a liquid cooling plate.

[0054] Example 2:

[0055] The preparation method of a multi-layer high-strength weldable composite plate for a liquid cooling plate in this example is specifically carried out according to the following steps:

[0056] 1. Saw, mill the surface and homogenize the core material Al-Si-Cu-Mg-Mn-Zr alloy ingot blank;

[0057] II. Place the 3003 alloy slab and the Al-Si-Cu-Mg-Mn-Zr alloy ingot blank processed in Step I in the order of 3003 / Al-Si-Cu-Mg-Mn-Zr / 3003, control the cladding ratios to be 18±3%, 72±3% and 10±2% in sequence, weld them by riveting, and then heat to a temperature of 450°C to 480°C and perform rolling to obtain a three-layer hot-rolled slab;

[0058] III. Cold-roll the three-layer hot-rolled slab obtained in Step II to the finished thickness, then perform finished annealing at an annealing temperature of 300°C to 380°C for 2h to 3h, air-cool after taking out of the furnace, and then perform leveling and shearing to obtain a three-layer high-strength weldable composite plate for liquid cooling plates.

[0059] The preparation method of the Al-Si-Cu-Mg-Mn-Zr alloy ingot blank in Examples 1 and 2 is carried out according to the following steps:

[0060] A. According to the mass percentages of each element: Si is 0.5%, Mg is 0.85%, Mn is 0.30%, Cu is 0.4%, Zn is 0.3%, Ti is 0.025%, Zr is 0.1%, Fe < 0.15%, and the balance is Al. Weigh pure aluminum ingots, pure magnesium ingots, pure zinc ingots, aluminum-silicon master alloy, manganese agent, aluminum-copper master alloy, aluminum-titanium-boron wire grain refiner and aluminum-zirconium master alloy; among them, the aluminum-silicon master alloy is Al-22% Si alloy, 75% of the manganese agent, the aluminum-copper master alloy is Al-40% Cu alloy, the aluminum-titanium master alloy is Al-5% Ti alloy, the aluminum-titanium-boron wire grain refiner is Al-0.5% Ti-0.2% B alloy, and the aluminum-zirconium master alloy is Al-3% Zr alloy;

[0061] B. Add the pure aluminum ingots, pure zinc ingots, aluminum-silicon master alloy, manganese agent, aluminum-copper master alloy and aluminum-zirconium master alloy weighed in Step A to the melting furnace, raise the temperature to 760°C, melt and stir, remove the slag, then add pure magnesium ingots, add Covering agent No. 1, melt for 30 min, and then refine with an Ar-Cl2 mixed gas until the hydrogen content in every 100 grams of the aluminum alloy melt is ≤0.25 mL, and let it stand for 30 min to obtain an aluminum alloy melt; Covering agent No. 1 is Flux No. 1, and Flux No. 1 is composed of 50% KCl, 26% NaCl and 24% NaAlF6 by weight percentage; the dosage of Covering agent No. 1 is 0.45% of the total mass of the melt in the melting furnace;

[0062] C. Filter the aluminum alloy melt obtained in Step B successively through ceramic filter plates with 30 ppi and 50 ppi, then pour it into the mold, and at the same time insert the aluminum-titanium-boron wire grain refiner into the launder and uniformly melt it into the aluminum alloy melt; the insertion speed of the aluminum-titanium-boron wire grain refiner is 340 mm / min;

[0063] D. At a temperature of 720 °C and a water pressure of 95 m 3 / h and a speed of 45 mm / min, it is cast into an Al-Si-Cu-Mg-Mn-Zr alloy ingot with a thickness of 440 mm, a width of 1450 mm, and a length of 5000 mm.

[0064] The casting method of the 4045 alloy slab in step two is specifically carried out according to the following steps:

[0065] Weigh industrial pure aluminum ingots, aluminum-silicon master alloy, and Al-Ti-B wire according to the mass percentages of each element as follows: Si is 9.9%, Fe < 0.80%, Cu < 0.30%, Mn < 0.05%, Mg < 0.05%, Zn < 0.10%, Ti < 0.20%, and the balance is aluminum; then add the industrial pure aluminum ingots and aluminum-silicon master alloy to the melting furnace, heat up to 740 - 760 °C for melting and stirring, after stirring, refining, and adjusting the composition, it enters the holding furnace, and after degassing and slag removal, the Al-Ti-B wire is spot-welded online at 730 °C for casting.

[0066] The casting method of the 3003 alloy slab in step two is specifically carried out according to the following steps:

[0067] Weigh industrial pure aluminum ingots, aluminum-copper master alloy, and aluminum-manganese master alloy according to the mass percentages of each element as follows: Si < 0.60%, Fe < 0.7%, Mn is 1.17%, Cu is 0.11%, Zn < 0.1%, and the balance is aluminum; add the industrial pure aluminum ingots, aluminum-copper master alloy, and aluminum-manganese master alloy to the melting furnace, heat up to 750 °C for melting and stirring, after stirring, refining, and adjusting the composition, it enters the holding furnace, and after degassing and slag removal, the Al-Ti-B wire is spot-welded online at 730 °C for casting.

[0068] The above-mentioned three-layer and four-layer high-strength weldable composite plates are applied to battery liquid cooling plates;

[0069] The brazing temperature of the four-layer and three-layer composite plates prepared in step three is 610 °C, and it is held for 10 min.

[0070] The macroscopic morphology photo of the Al-Si-Cu-Mg-Mn-Zr alloy ingot blank described in this embodiment is as Figure 1 shown. The specification is 440×1450×5000 mm.

[0071] Figure 2 It is the macroscopic morphology photo of the three-layer composite plate prepared in Example 1;

[0072] Figure 3 It is the welding and assembly application photo of the battery liquid cooling plate prepared in Example 1.

[0073] The tensile strength of the four-layer composite plate prepared in the above embodiment before brazing is 107 MPa, the yield strength is 55 MPa, and the elongation is 27.6%. The tensile strength of the three-layer composite plate before brazing is 111 MPa, the yield strength is 65 MPa, and the elongation is 25%. After artificial aging treatment of the three-layer and four-layer composite plates under the same brazing system, the tensile strength is ≥200 MPa, the yield strength is ≥150 MPa, and the elongation is ≥12%.

[0074] The tensile strength of the four-layer composite plate prepared by the present invention after brazing + artificial aging treatment is 221 MPa, the yield strength is 167 MPa, and the elongation is 12%. The tensile strength of the three-layer composite plate after brazing + artificial aging treatment is 224 MPa, the yield strength is 175 MPa, and the elongation is 12.4%. The tensile strength of the commonly used 4343 / 3003 composite plate for battery liquid cooling plates on the market before brazing is 95 MPa, the yield strength is 40 MPa, and the elongation is 17%. The tensile strength after brazing is 120 MPa, the yield strength is 55 MPa, and the elongation is 20%. Comparing the mechanical properties of the prepared three-layer and four-layer composite plates with those of the 4343 / 3003 composite plate, the strength before brazing is increased by 13%, and the strength after brazing is increased by 84%. This makes the three-layer and four-layer composite plates for battery liquid cooling plates not only meet the design material selection requirements of battery liquid cooling plates, but also be more conducive to the popularization and use of brazed battery liquid cooling plates.

Claims

1. A multi-layer high-strength weldable composite plate for a liquid cooling plate, characterized in that, The multi-layer high-strength weldable composite plate is a four-layer high-strength weldable composite plate or a three-layer high-strength weldable composite plate; among them, the four-layer high-strength weldable composite plate is rolled from a 4045 alloy slab, a 3003 alloy slab, and an Al-Si-Cu-Mg-Mn-Zr alloy ingot blank in the order of 4045 / 3003 / Al-Si-Cu-Mg-Mn-Zr / 3003; the three-layer high-strength weldable composite plate is rolled from a 3003 alloy slab and an Al-Si-Cu-Mg-Mn-Zr alloy ingot blank in the order of 3003 / Al-Si-Cu-Mg-Mn-Zr / 3003.

2. The preparation method of a multi-layer high-strength weldable composite plate for a liquid cooling plate according to claim 1, characterized in that, The multi-layer high-strength weldable composite plate used for the liquid cooling plate is a four-layer high-strength weldable composite plate; the preparation method of the four-layer high-strength weldable composite plate is as follows: First, saw, mill, and homogenize the core Al-Si-Cu-Mg-Mn-Zr alloy ingot blank to obtain the treated Al-Si-Cu-Mg-Mn-Zr alloy ingot blank. Second, place the 4045 alloy slab, the 3003 alloy slab, and the treated Al-Si-Cu-Mg-Mn-Zr alloy ingot blank in the order of 4045 / 3003 / Al-Si-Cu-Mg-Mn-Zr / 3003, control the cladding ratios to be 8±2%, 15±3%, 67±2%, and 10±2% in sequence, weld by riveting, then heat to a temperature of 450°C to 480°C, and perform rolling to obtain a four-layer hot-rolled slab. Third, cold-roll the four-layer hot-rolled slab to the finished thickness, then perform finished annealing, the annealing temperature is 300°C to 380°C, hold for 2h to 3h, air-cool after taking out of the furnace, and then level and shear to obtain a four-layer high-strength weldable composite plate.

3. The preparation method of a multi-layer high-strength weldable composite plate for a liquid cooling plate according to claim 1, characterized in that, The multi-layer high-strength weldable composite plate used for the liquid cooling plate is a three-layer high-strength weldable composite plate; the preparation method of the three-layer high-strength weldable composite plate is as follows: First, saw, mill, and homogenize the core Al-Si-Cu-Mg-Mn-Zr alloy ingot blank to obtain the treated Al-Si-Cu-Mg-Mn-Zr alloy ingot blank. Second, place the 3003 alloy slab and the treated Al-Si-Cu-Mg-Mn-Zr alloy ingot blank in the order of 3003 / Al-Si-Cu-Mg-Mn-Zr / 3003, control the cladding ratios to be 18±3%, 72±3%, and 10±2% in sequence, weld by riveting, then heat to a temperature of 450°C to 480°C, and perform rolling to obtain a three-layer hot-rolled slab. Third, cold-roll the three-layer hot-rolled slab to the finished thickness, then perform finished annealing, the annealing temperature is 300°C to 380°C, hold for 2h to 3h, air-cool after taking out of the furnace, and then level and shear to obtain a three-layer high-strength weldable composite plate.

4. The preparation method of a multi-layer high-strength weldable composite plate for a liquid cooling plate according to claim 2 or 3, characterized in that The preparation method of the Al-Si-Cu-Mg-Mn-Zr alloy ingot blank is as follows: Carry out according to the following steps: A. According to the mass percentages of each element: Si is 0.30% - 0.90%, Mg is 0.40% - 1.3%, Mn is 0.05% - 0.90%, Cu is 0.10% - 1.0%, Zn is 0.10% - 0.60%, Ti is 0.01% - 0.20%, Zr is 0.03% - 0.25%, Fe < 0.30%, and the balance is Al, weigh pure aluminum ingots, pure magnesium ingots, pure zinc ingots, aluminum-silicon master alloy, manganese agent, aluminum-copper master alloy, aluminum-titanium-boron wire grain refiner, and aluminum-zirconium master alloy; B. Add the pure aluminum ingots, pure zinc ingots, aluminum-silicon master alloy, manganese agent, aluminum-copper master alloy, and aluminum-zirconium master alloy weighed in step A to the melting furnace, heat up to 740 - 760 °C, melt and stir, add pure magnesium ingots after slag removal, add No. 1 covering agent, melt for 15 min - 30 min, then refine with Ar-Cl2 mixed gas until the hydrogen content in every 100 grams of aluminum alloy melt ≤ 0.25 mL, and let it stand for 30 min to obtain aluminum alloy melt; C. Filter the aluminum alloy melt obtained in step B successively through ceramic filter plates with 30 ppi and 50 ppi, then pour it into the mold, and at the same time insert the aluminum-titanium-boron wire grain refiner into the launder and uniformly melt it into the aluminum alloy melt; The insertion speed of the aluminum-titanium-boron wire grain refiner is 340 mm / min; D. Under the conditions of a temperature of 710°C to 750°C, a water pressure of 80 to 110 m 3 / h, and a speed of 30 to 60 mm / min, an Al-Si-Cu-Mg-Mn-Zr alloy ingot with a thickness of 440 mm, a width of 1450 mm, and a length of 1500 mm to 5500 mm is cast.

5. The preparation method of a multi-layer high-strength weldable composite plate for a liquid cooling plate according to claim 4, characterized in that, The No. 1 covering agent is Flux 1#, and Flux 1# is composed of 50% KCl, 26% NaCl, and 24% NaAlF6 by weight percentage; the dosage of the No. 1 covering agent is 0.4 - 0.6% of the total mass of the melt in the melting furnace.

6. The preparation method of a multi-layer high-strength weldable composite plate for a liquid cooling plate according to claim 2 or 3, characterized in that, The casting method of the 4045 alloy slab is as follows: Weigh industrial pure aluminum ingots, aluminum-silicon master alloy, and Al-Ti-B wire according to the mass percentages of each element: Si is 9.0% - 11.0%, Fe < 0.80%, Cu < 0.30%, Mn < 0.05%, Mg < 0.05%, Zn < 0.10%, Ti < 0.20%, and the balance is aluminum; Then add the industrial pure aluminum ingots and aluminum-silicon master alloy to the melting furnace, heat up to 740 - 760 °C to melt and stir, enter the holding furnace after stirring, refining, and adjusting the composition, degas and remove slag, and then cast by online feeding of Al-Ti-B wire at 720 °C - 740 °C.

7. The preparation method of a multi-layer high-strength weldable composite plate for a liquid cooling plate according to claim 2 or 3, characterized in that, The casting method of the 3003 alloy slab is specifically carried out according to the following steps: Weigh industrial pure aluminum ingots, aluminum-copper master alloy, and aluminum-manganese master alloy according to the mass percentages of each element: Si < 0.60%, Fe < 0.7%, Cu is 0.05% - 0.20%, Mn is 1.0% - 1.5%, Zn < 0.1%, and the balance is aluminum; add the industrial pure aluminum ingots, aluminum-copper master alloy, and aluminum-manganese master alloy to the melting furnace, heat up to 740 - 760 °C to melt and stir, enter the holding furnace after stirring, refining, and adjusting the composition, degas and remove slag, and then cast by online feeding of Al-Ti-B wire at 720 °C - 740 °C.

8. The application of a multi-layer high-strength weldable composite plate for a liquid cooling plate in a battery liquid cooling plate as described in claim 1.

9. The application according to claim 8, wherein The multi-layer high-strength weldable composite plate for liquid cooling plates is a three-layer high-strength weldable composite plate and is applied to the panel for battery liquid cooling plates.

10. The application according to claim 8, wherein The multi-layer high-strength weldable composite plate for liquid cooling plates is a four-layer high-strength weldable composite plate and is applied to the flow channel for battery liquid cooling plates.

Images