CN111086289B

CN111086289B - Water-cooling plate, manufacturing method thereof, battery comprising water-cooling plate and new energy automobile

Info

Publication number: CN111086289B
Application number: CN201911370719.3A
Authority: CN
Inventors: 伍波; 郭耿锋; 李卫东; 唐友增; 夏承东
Original assignee: Yinbang Clad Material Co Ltd
Current assignee: Yinbang Clad Material Co Ltd
Priority date: 2019-12-26
Filing date: 2019-12-26
Publication date: 2021-12-21
Anticipated expiration: 2039-12-26
Also published as: CN111086289A

Abstract

The invention discloses a water cooling plate, a manufacturing method thereof, a battery comprising the water cooling plate and a new energy automobile. The water-cooling plate comprises an A composite plate and a B composite plate with a flow channel, wherein the A composite plate comprises a core material layer aluminum alloy and a water contact layer aluminum alloy which are sequentially compounded; the B composite board comprises a brazing layer aluminum alloy, a core material layer aluminum alloy and a protective layer aluminum alloy which are sequentially compounded; welding the aluminum alloy of the water contact layer of the composite plate A with the aluminum alloy of the brazing layer of the composite plate B; the core material layer aluminum alloy comprises the following materials in percentage by mass: less than or equal to 0.5 percent of Si, less than or equal to 0.5 percent of Fe, 0.25 to 0.8 percent of Cu, 1.0 to 2.0 percent of Mn, less than or equal to 0.05 percent of Zn, 0.05 to 0.15 percent of Ti, the balance of Al and single elements less than 0.05 percent, and the total amount of unavoidable impurities less than 0.15 percent. The manufacturing method of the water cooling plate comprises the steps of rolling, annealing, shearing, B composite plate forming, assembling and welding to obtain the water cooling plate. Batteries, new energy automobile include water cooling board. The water-cooling plate disclosed by the invention has the advantages of high strength after brazing, small size and plate shape deformation, suitability for punch forming and good corrosion resistance.

Description

Water-cooling plate, manufacturing method thereof, battery comprising water-cooling plate and new energy automobile

Technical Field

The present disclosure relates to a water cooling panel, a method of manufacturing the water cooling panel, a battery including the water cooling panel, and a new energy vehicle including the battery.

Background

With the rapid development of the automobile industry, the problems of environmental pollution, energy shortage, resource exhaustion, safety and the like brought by automobiles become more and more prominent. The new energy automobile has the remarkable characteristics of good environmental protection performance and capability of taking multiple energy sources as power, thereby not only protecting the environment, but also relieving the energy shortage and ensuring the energy safety. In 2018, the new energy automobile production and marketing in China respectively finish 127 ten thousand and 125.6 ten thousand, and the new energy automobile production and marketing are respectively increased by 59.9 percent and 61.7 percent compared with the new energy automobile production and marketing in the same period in the last year. The core structure of the new energy automobile, namely the power battery, is an indispensable power output source of the new energy automobile at present.

The power battery of the new energy automobile is very sensitive to temperature. The battery temperature may gradually increase during use, and when the temperature is too high, thermal runaway of the battery may occur, and thus, it is important to cool the battery pack. The water cooling plate is used as an important component of liquid cooling, the surface of the water cooling plate is in full contact with the surface of the battery, and heat of the battery is taken away by cooling liquid flowing in the water cooling plate to carry out heat exchange, so that the temperature of the battery is reduced.

The conventional new energy automobile battery water cooling plate material is formed by welding 1xxx series and 3xxx series aluminum alloys. With the continuous popularization of new energy automobiles, higher and higher requirements are provided for the comprehensive performance of the battery water cooling plate including mechanical properties, and the 1xxx aluminum alloy and the common 3003 aluminum alloy water cooling plate material are limited by the strength and are difficult to meet the requirements of customers.

In order to improve strength, 6xxx aluminum alloy is also used as the material of the water cooling plate. Li Qi et al studied the 6061 aluminum alloy water-cooling plate diffusion welding process and welding performance thereof, and discovered that reliable welding of 6061 water-cooling plates was achieved under the conditions of the welding temperature of 530 ℃, the heat preservation time of 7h and the welding pressure of 3.5MPa by the influence of the welding temperature (490-540 ℃), the welding pressure and the heat preservation time on welding joints. 6xxx aluminum alloys, such as 6061 aluminum alloy, are a class of heat treatable strengthened aluminum alloys that can achieve desirable strength through proper solution aging treatment, but because of their relatively low solidus temperature, after brazing at a high temperature of over 600 ℃, the structure is easily over-sintered, affecting their application.

Some have unique structures and complicated water cooling plate structures which cannot be machined by conventional machining means, and researchers have proposed related researches on applying 3D printing technology to water cooling plates. The Chua Yan photo and the like develop 3D printing aluminum alloy liquid cold plate performance research, and the research shows that: under the same input parameter condition, the performance of the two types of liquid cooling plates meets the requirements, and the heat dissipation and flow resistance performance of the 3D printing liquid cooling plate is superior to that of a vacuum diffusion welding liquid cooling plate. However, the 3D metal printing technique is difficult to be popularized and applied due to the limitations of high raw material cost, low yield, large surface roughness of the product, and the like.

Disclosure of Invention

It is an object of the present disclosure to provide a water cooled plate having a moderate post-braze strength.

The method is realized by the following technical scheme:

a water cooling plate comprises a composite plate A and a composite plate B with a runner; the A composite plate comprises a core material layer aluminum alloy and a water contact layer aluminum alloy which are sequentially arranged; the B composite plate comprises a brazing layer aluminum alloy, a core material layer aluminum alloy and a protective layer aluminum alloy which are sequentially arranged; welding the aluminum alloy of the water contact layer of the composite plate A with the aluminum alloy of the brazing layer of the composite plate B; the core material layer aluminum alloy comprises the following materials in percentage by mass: less than or equal to 0.5 percent of Si, less than or equal to 0.5 percent of Fe, 0.25 to 0.8 percent of Cu0, 1.0 to 2.0 percent of Mn, less than or equal to 0.05 percent of Zn, 0.05 to 0.15 percent of Ti, the balance of Al and single elements less than 0.05 percent, and the total amount of unavoidable impurities less than 0.15 percent.

According to some embodiments, the water contact layer aluminum alloy and the protective layer aluminum alloy comprise, in mass percent:

less than or equal to 0.7 percent of Si + Fe, 0.5 to 1.0 percent of Mn, 0.8 to 4.0 percent of Zn, less than or equal to 0.05 percent of Ti, and the balance of Al and inevitable impurities with the mass less than 0.15 percent.

According to some embodiments, the braze layer aluminum alloy is an Al-Si alloy including 5.0-11.0% Si by mass.

According to some embodiments, the composition ratio of the aluminum alloy in the water contact layer in the a composite plate is 5-12%; the compound ratio of the brazing layer aluminum alloy in the B composite board is 5-15%; the composite ratio of the protective layer aluminum alloy is 5-12%.

Another objective of the present disclosure is to disclose a method for manufacturing the above water-cooling plate, comprising the following steps:

rolling: respectively proportioning the alloys according to set components, and preparing A composite rolls and B composite rolls through casting, surface milling, heating, hot rolling and cold rolling;

annealing: the annealing temperature of the A composite coil is 325 +/-10 ℃, and the temperature is kept for 2-4 h; b, the annealing temperature of the composite coil is 380 +/-10 ℃, and the temperature is kept for 2-4 h;

and shearing, B composite board forming, assembling and welding to obtain the water-cooling board.

According to some embodiments, in the heating step: the core material layer cast ingot for rolling the B composite board is subjected to homogenization treatment at 600 +/-20 ℃ in a heating furnace, and the heating time is 12-24 hours.

According to some embodiments, the welding step is brazing in a CAB furnace at 605 ± 15 ℃.

The present disclosure also discloses a battery including above-mentioned water-cooling board to and including the new energy automobile of this battery.

The water-cooling plate disclosed by the invention has the advantages of high strength after brazing, small size and plate shape deformation, suitability for punch forming and good corrosion resistance. The mechanical property detection shows that the mechanical property of the water-cooling plate after welding is that the tensile strength is not lower than 145 MPa: the yield strength is not lower than 50MPa, and the elongation is not lower than 20%. After the water-cooled plate after being brazed is subjected to SWAAT simulated seawater salt spray experiment for 40 days, no leakage point is found through 2MPa compressed air pressurizing test.

Drawings

FIG. 1 is a schematic structural view of a cross section of a water-cooled panel according to the present disclosure;

FIG. 2 is a close-up view of a section of a water-cooled plate according to the present disclosure.

In the figure:

a, a composite board 1;

a board core layer 11;

a water contact layer 12;

b, a composite board 2;

a brazing layer 21;

b-board core layer 22;

a protective layer 23;

a groove 24;

and a flow channel 3.

Detailed Description

The following detailed description of the present disclosure is provided in conjunction with the accompanying drawings and examples to enable a better understanding of the aspects of the present disclosure and its advantages in various aspects. However, the specific embodiments and examples described below are for illustrative purposes only and are not limiting of the present disclosure.

The terms "connected" and "connected" as used in this disclosure are intended to be broadly construed, and may be directly connected or connected through an intermediate, unless otherwise expressly specified or limited. In the description of the present disclosure, it is to be understood that the directions or positional relationships indicated by "upper", "lower", "front", "rear", "left", "right", "top", "bottom", and the like are based on the directions or positional relationships shown in the drawings, and are only for convenience of describing the present disclosure and simplifying the description, but do not indicate or imply that the device or element referred to must have a specific direction, be configured and operated in a specific direction, and thus, cannot be construed as limiting the present disclosure.

The disclosure relates to a water-cooling plate, wherein fig. 1 is a schematic structural diagram of a cross section of the water-cooling plate disclosed by the disclosure, fig. 2 is a partial enlarged view of the cross section of the water-cooling plate disclosed by the disclosure, and the water-cooling plate comprises an a composite plate 1 and a B composite plate 2, which are shown in combination with fig. 1 and fig. 2. B composite panel 2 is provided with grooves 24. The a-composite sheet 1 includes a core material layer 11 and a water contact layer 12 which are sequentially arranged and compounded. The B-composite board 2 includes a brazing layer 21, a core material layer 22, and a protective layer 23, which are sequentially laminated. The water contact layer 12 of the composite plate A1 faces the brazing layer 21 of the composite plate B2 and is integrally fixed through brazing to form the water cooling plate with the flow channel 3.

Wherein core layer 11 of composite panel a 1 and core layer 22 of composite panel B2 both employ a modified 3003 aluminum alloy, referred to herein as 3003mod1 aluminum alloy. The 3003mod1 aluminum alloy includes the following materials in mass percent: less than or equal to 0.5 percent of Si, less than or equal to 0.5 percent of Fe, 0.25 to 0.8 percent of Cu, 1.0 to 2.0 percent of Mn, less than or equal to 0.05 percent of Zn, 0.05 to 0.15 percent of Ti, the balance of Al and single elements less than 0.05 percent, and the total amount of unavoidable impurities less than 0.15 percent. The water-contact layer 12 and the protective layer 23 were made of a modified 7072 aluminum alloy, referred to as 7072mod1 aluminum alloy. The 7072mod1 aluminum alloy includes the following materials in mass percent: less than or equal to 0.7 percent of Si + Fe, 0.5 to 1.0 percent of Mn, 0.8 to 4.0 percent of Zn, less than or equal to 0.05 percent of Ti, and the balance of Al and inevitable impurities with the mass less than 0.15 percent.

The brazing layer 21 is made of Al-Si alloy with Si content of 5.0-11.0% by mass.

In the A composite board, the composite ratio of the aluminum alloy in the water contact layer is 5-12%; in the B composite board, the composite ratio of the brazing layer aluminum alloy is 5-15%; the composite ratio of the protective layer aluminum alloy is 5-12%.

And brazing the composite plate A and the composite plate B to form the water cooling plate.

The manufacturing method of the water cooling plate comprises the following steps:

1) casting: smelting according to the element proportion, and obtaining a flat cast ingot with a certain specification through melting, electromagnetic stirring, slag skimming, degassing, refining and semi-continuous casting.

2) Casting ingot surface milling: and milling the flat cast ingot according to the specification requirement, wherein the milling amount of the upper surface and the lower surface is 5-15 mm, and the milling amount of the small surfaces on two sides is 0-10 mm.

3) Ingot casting and heating: heating and insulating the cast ingot in a heating furnace:

casting ingots by using a core material layer 3003mod1 of the B composite board, carrying out homogenization treatment at 600 +/-20 ℃ in a heating furnace, taking the ingots out of the furnace and cooling the ingots after the heating time is 12-24 hours;

next, an ingot for manufacturing a composite board a and an ingot for manufacturing B composite board (in which the core material has been homogenized) are stacked in order, and welded and fixed along the edges to prevent sliding between the ingot layers. And (3) preserving the heat of the fixed multilayer cast ingot for 2-4h at 500 +/-50 ℃.

4) Hot rolling: and (3) carrying out multi-pass hot rolling on the ingots for manufacturing the A composite plate and the B composite plate to the thickness of 5-8 mm, rolling, wherein the initial rolling temperature is 480 +/-20 ℃, and the final rolling temperature is not lower than 300 ℃.

5) Cold rolling: the hot rolled material of the A, B composite plate is cold rolled to the thickness of 1.0-2.0mm for coiling in multiple passes.

Wherein the thickness of the cold-rolled finished product of the composite plate A is 1.5-2.0mm, and the thickness of the cold-rolled finished product of the composite plate B is 1.0-1.5 mm.

6) Annealing of a finished product: and annealing the cold-rolled coil in a nitrogen protection heating furnace.

A. The annealing temperatures of the B composite boards are different:

the annealing temperature of the finished product of the composite aluminum material in the step A is 325 +/-10 ℃, and the annealing temperature of the finished product of the composite aluminum material in the step B is 380 +/-10 ℃.

The annealing process under the protection of nitrogen can effectively avoid the generation of oil spots on the surface of the composite board. The oil spots reduce the surface quality of the composite board and have adverse effects on the subsequent brazing quality.

7) Shearing: and cutting the annealed A, B composite plate coil into aluminum plates with different specification sizes according to specific specification requirements.

8) The B composite plate is punched into a specific groove structure from top to bottom along the Al-Si alloy surface by a die so as to form a water-cooling plate runner after the B composite plate is brazed with the A composite aluminum material.

9) Assembling: and assembling the water contact layer of the composite plate A facing the brazing layer of the composite plate B to form a water-cooling plate structure.

10) Controlling atmosphere protection welding: and (3) performing CAB shielded welding brazing on the water cooling plate assembled by the composite plate A and the composite plate B at the temperature of 605 +/-15 ℃ for 20-60min to prepare the water cooling plate disclosed by the invention.

From the chemical composition perspective, the composite plate A and the composite plate B prepared by the method both adopt 3003mod1 as core materials, compared with the common 3003 aluminum alloy, the Mn content in the 3003mod1 is 1.0-2.0%, the Mn element content is increased, and the effects of increasing strength, refining crystal grains and improving deep drawing performance can be achieved; in addition, manganese also reduces the embrittlement of iron-containing phases, i.e. the needle-like or flake-like iron-containing compounds are converted into less brittle, massive compounds. When the Mn content is less than 0.5%, the strength is insufficient. However, excessive coarse Al — Mn phases are formed at Mn contents higher than 2%, and the inventors have found that the improvement of strength is remarkable when Mn contents of not less than 1.0% are preferred, and in order to improve the strength of the composite panel, Mn of not less than 1.0% is preferred in the present disclosure. Addition of an appropriate amount of Fe replaces Mn atoms of the Al-Mn phase to produce (FeMn) Al₆Phase, right amount of (FeMn) Al₆The existence of the phase can effectively avoid the accumulation of aluminum scraps in the die in the stamping process. Increasing the Cu content helps to improve the strength before and after brazing of the 3xxx series alloys: when the content of Cu is less than 0.1%, it exists mainly in a solid solution form in the matrix; when the Cu content exceeds 0.1%, Al is formed₂The Cu phase is helpful for improving the strength of the material, and the inventor finds that the Cu content of not less than 0.25% preferably has a remarkable influence on the improvement of the strength of the material. In addition, the addition of a small amount of Cu is beneficial to improving the corrosion resistance of the alloy and can change from pitting corrosion to overall uniform corrosion, but the content of Cu is not too high, otherwise the corrosion resistance of the alloy is reduced, and the Cu content is preferably not higher than 0.8 percent. The Ti is added into the core alloy, can refine cast crystal grains, prevent casting cracking and improve the corrosion resistance of the alloy, but the content of the Ti is not more than 0.15 percent, otherwise coarse Al is formed₃Ti phase, which reduces the mechanical properties of the alloy.

The water contact layer of composite panel a and the protective layer of composite panel B were used as 7072mod 1. Compared with 7072 aluminum alloy, the 7072mod1 aluminum alloy is added with Mn element, which is beneficial to further improving the strength of the whole composite material, and meanwhile, the Zn content is increased to improve the corrosion resistance, so that the electrochemical potential of 7072mod1 can be reduced.

From the perspective of the alloy state: the core materials of the composite board A and the composite board B are annealed at different temperatures, and different crystal grain states are obtained, so that different performances are obtained: annealing the composite board A at 325 +/-10 ℃, wherein the core material is still in an unrecrystallized state, the grain structure is still fibrous, and after high-temperature brazing, the grain structure is recrystallized and grows up, but the recrystallized grains are flat along the rolling direction. Corrosion generally corrodes along grain boundaries, with elongated flat grains being more corrosion resistant than equiaxed grains. The B alloy is completely recrystallized and annealed at 380 +/-10 ℃, and crystal grains of the core material are kept in a near-equiaxial crystal state after high-temperature brazing, so that the structural state is favorable for avoiding cracking in the later stamping process.

From the structural design perspective: the composite of a layer of Al-Zn alloy (such as 7072) on the surface of the 3xxx series Al-Mn alloy can increase the service life of the material. The corrosion potential of the Al-Zn alloy is lower than that of the Al-Mn alloy, and the Al-Zn alloy is used as an anode to preferentially corrode in a corrosion medium, so that the corrosion speed of the core material Al-Mn alloy is slowed down, and the corrosion life of the material is prolonged. However, the inventors found that in practical applications, because the mutual diffusion of Zn and Cu elements occurs during the high-temperature brazing process, that is, the Zn element as the anode sacrificial layer diffuses into the Al — Mn alloy core material, the Cu element (if any) in the core material diffuses into the sacrificial layer, so that the potential difference between the core material and the sacrificial layer is too small, and the anode protection effect is not obvious. According to the 7072 aluminum alloy, the content of Zn element is increased, so that the corrosion potential can be further reduced, the core material and a water contact layer have enough potential difference, but the Zn content is not too high, the Zn content is too high, the potential of an Al-Zn layer is too low, the anode corrosion rate is too high, and the effect of delaying the corrosion of the core material cannot be achieved.

The brazing type water-cooling plate prepared by the method has the characteristics of high strength, easiness in forming and corrosion resistance. The advantageous effects of the present disclosure are illustrated by examples below.

Example 1

The present example provides a water-cooled plate brazed from two composite materials, a and B, wherein the compositions of the aluminum alloys are shown in the following table.

The preparation method of the water cooling plate comprising the composite plates A and B is carried out according to the following steps:

1) casting: the Al-Si cast ingot, the 3003mod1 cast ingot and the 7072mod1 cast ingot are obtained by respectively proportioning the alloys according to the set components, melting the raw materials, electromagnetically stirring, slagging off, degassing, refining and semicontinuous casting, and the specifications of the Al-Si cast ingot, the 3003mod1 cast ingot and the 7072mod1 cast ingot are 450mm multiplied by 1250mm multiplied by 5000 mm.

2) Casting ingot surface milling: the Al-Si ingot, 3003mod1 ingot and 7072mod1 ingot were milled to 10mm each on both sides.

2.1) pre-hot rolling of a brazing layer and a water contact layer: Al-Si ingots and 7072mod1 ingots were hot rolled to 28mm and 57mm thickness respectively and cut into 4800mm long slabs.

3) Heating: 7072mod1, which is 57mm thick, and 3003mod1 alloy, which is 430mm thick, are stacked in this order from top to bottom and fixed by spot welding. And (3) heating the fixed two layers of composite blanks in a heating furnace at 500 ℃, wherein the heating section is 10-16h, and the heat preservation section is 2-6 h.

In addition, firstly, homogenizing 3003mod1 core material ingots used for manufacturing the B composite board at 600 ℃ for 16h, after homogenizing the core material ingots, stacking 28mm of Al-Si skin materials, 430mm of 3003mod1 and 57mm of 7072mod1 alloy in an up-and-down sequence, performing spot welding, and then putting into a heating furnace for heating at 500 ℃, wherein the heating section is 10-16h, and the heat preservation section is 2-6 h. 4) Hot rolling: respectively hot-rolling the two-layer composite material and the three-layer composite material in the step 3) to 6.0mm, and coiling to form two-layer A alloy hot-rolled coils and three-layer B alloy hot-rolled coils.

5) Cold rolling: after the A, B alloy hot-rolled coil is cooled to room temperature, the alloy hot-rolled coil is respectively cold-rolled to 2.0mm and 1.0mm by multiple passes.

6) Annealing: cold rolling A, B on N₂Annealing at 325 +/-10 deg.C and 380 +/-10 deg.C in protecting annealing furnace, and holdingThe time is 2-4 h.

7) Shearing: and respectively cutting the annealed A, B coils into plates with certain sizes.

8) Stamping: and (3) placing the B composite board upwards by using the Al-Si layer, and stamping by using a die to form a downward groove.

9) Assembling: and assembling the 7072mod layer of the composite plate A and the Al-Si layer of the composite plate B in a face-to-face mode, and clamping the tool.

10) Brazing: and (3) brazing the assembled A, B composite board at the high temperature of 600 ℃ and 620 ℃ to finish the preparation of the public water cooling board.

The mechanical property detection shows that the mechanical property of the water cooling plate after welding is that the tensile strength is 150 MPa: the yield strength is 55MPa, and the elongation is 20%. After the water-cooled plate after being brazed is subjected to SWAAT simulated seawater salt spray experiment for 40 days, no leakage point is found through 2MPa compressed air pressurizing test.

Example 2

1) casting: the Al-Si cast ingot, the 3003mod cast ingot and the 7072mod cast ingot are obtained by respectively proportioning the alloys according to the set components, and carrying out raw material melting, electromagnetic stirring, slag skimming, degassing, refining and semi-continuous casting, wherein the specifications of the Al-Si cast ingot, the 3003mod cast ingot and the 7072mod cast ingot are 450mm multiplied by 1250mm multiplied by 5000 mm.

2) Casting ingot surface milling: the two surfaces of the Al-Si ingot, the 3003mod ingot and the 7072mod ingot are milled by 10mm respectively.

2.1) pre-hot rolling of a brazing layer and a water contact layer: the Al-Si ingot and the 7072mod ingot were hot rolled to 33mm and 26mm thickness, respectively, and cut into 4800mm long slabs.

3) Heating: 7072mod1, 26mm thick, was stacked in this order with 3003mod1 alloy, 430mm thick, and spot welded. And (3) heating the fixed two layers of composite blanks in a heating furnace at 500 ℃, wherein the heating section is 10-16h, and the heat preservation section is 2-6 h.

In addition, firstly, homogenizing 3003mod1 core material ingots used by the B composite board at 600 ℃ for 16h, after homogenizing the core material ingots, stacking 33mm of Al-Si skin materials, 430mm of 3003mod1 and 26mm of 7072mod1 alloy in an up-and-down sequence, performing spot welding, and then putting the materials into a heating furnace for heating at 500 ℃, wherein the heating section is 10-16h, and the heat preservation section is 2-6 h.

4) Hot rolling: respectively hot-rolling the two-layer composite material and the three-layer composite material in the step 3) to 6.0mm, and coiling to form two-layer A alloy hot-rolled coils and three-layer B alloy hot-rolled coils.

5) Cold rolling: after the A and B composite materials are cooled to room temperature, the A and B composite materials are respectively cold-rolled to 1.0mm and 1.0mm in multiple passes.

6) Annealing: and (3) respectively annealing the A and B cold-rolled coils in an N2 protective annealing furnace at 325 +/-10 ℃ and 380 +/-10 ℃ for 2-4 h.

7) Shearing: respectively cutting the annealed A and B coiled materials to plate materials with certain sizes;

8) stamping: and stamping the B composite plate into a specific runner through a die.

9) Assembling: assembling the 7072mod layer of the A composite material and the Al-Si layer of the B composite material in opposite directions, and clamping the tool.

10) Brazing: and (3) brazing the assembled water cooling plate at the high temperature of 600-620 ℃ to finish the preparation of the water cooling plate.

The mechanical property detection shows that the mechanical property of the water cooling plate after welding is that the tensile strength is 155 MPa: the yield strength is 61MPa, and the elongation is 26%. After the water-cooled plate after being brazed is subjected to SWAAT simulated seawater salt spray experiment for 40 days, no leakage point is found through 2MPa compressed air pressurizing test.

Example 3

2.1) pre-hot rolling of a brazing layer and a water contact layer: the Al-Si ingot and the 7072mod ingot were hot rolled to 78mm and 33mm thickness, respectively, and cut into 4800mm long slabs.

3) Heating: 7072mod1, which is 33mm thick, and 3003mod1 alloy, which is 430mm thick, are stacked in this order from top to bottom and fixed by spot welding. And (3) heating the fixed two layers of composite blanks in a heating furnace at 500 ℃, wherein the heating section is 10-16h, and the heat preservation section is 2-6 h.

In addition, firstly, homogenizing 3003mod1 core material ingots used by the B composite board at 600 ℃ for 16h, after homogenizing the core material ingots, stacking 78mm of Al-Si skin materials, 430mm of 3003mod1 and 33mm of 7072mod1 alloy in an up-and-down sequence, performing spot welding, and then putting the materials into a heating furnace for heating at 500 ℃, wherein the heating section is 10-16h, and the heat preservation section is 2-6 h.

5) Cold rolling: after the A and B composite materials are cooled to room temperature, the A and B composite materials are respectively cold-rolled to 1.2mm and 12mm in multiple passes.

The mechanical property detection shows that the mechanical property of the water-cooling plate after welding is that the tensile strength is 145 MPa: the yield strength is 53MPa, and the elongation is 24%. After the water-cooled plate after being brazed is subjected to SWAAT simulated seawater salt spray experiment for 40 days, no leakage point is found through 2MPa compressed air pressurizing test.

It should be noted that the above-mentioned embodiments described with reference to the drawings are only intended to illustrate the present disclosure, not to limit the scope of the present disclosure, and it should be understood by those skilled in the art that modifications or equivalent substitutions made on the present disclosure without departing from the spirit and scope of the present disclosure should be included in the scope of the present disclosure. Furthermore, unless the context indicates otherwise, words that appear in the singular include the plural and vice versa. Additionally, all or a portion of any embodiment may be utilized with all or a portion of any other embodiment, unless stated otherwise.

Claims

1. A water-cooling plate comprises a composite plate A and a composite plate B with a groove; it is characterized in that the preparation method is characterized in that,

the A composite plate comprises a core material layer aluminum alloy and a water contact layer aluminum alloy which are sequentially compounded;

the B composite plate comprises a brazing layer aluminum alloy, a core material layer aluminum alloy and a protective layer aluminum alloy which are sequentially compounded;

welding the aluminum alloy of the water contact layer of the composite plate A with the aluminum alloy of the brazing layer of the composite plate B;

the core material layer aluminum alloy comprises the following materials in percentage by mass:

less than or equal to 0.5 percent of Si, less than or equal to 0.5 percent of Fe, 0.25 to 0.8 percent of Cu, 1.0 to 2.0 percent of Mn, less than or equal to 0.05 percent of Zn, 0.05 to 0.15 percent of Ti, the balance of Al and single elements less than 0.05 percent, and the total amount of unavoidable impurities less than 0.15 percent;

the water contact layer aluminum alloy and the protective layer aluminum alloy comprise the following materials in percentage by mass: less than or equal to 0.7 percent of Si + Fe, 0.5 to 1.0 percent of Mn, 0.8 to 4.0 percent of Zn, less than or equal to 0.05 percent of Ti, and the balance of Al and inevitable impurities with the mass less than 0.15 percent;

the brazing layer aluminum alloy is an Al-Si alloy containing 5.0-11.0% of Si by mass percent.

2. The water-cooled plate of claim 1, wherein the composition ratio of the aluminum alloy in the water contact layer of the a composite plate is 5 to 12%.

3. The water-cooling plate of claim 1, wherein the composition ratio of the brazing layer aluminum alloy in the B composite plate is 5-15%; the composite ratio of the protective layer aluminum alloy is 5-12%.

4. A method of manufacturing a water-cooled plate as claimed in any one of claims 1 to 3, including the steps of:

annealing: the annealing temperature of the A composite roll is 325 +/-10 ℃; the annealing temperature of the B composite coil is 380 +/-10 ℃;

5. The method of claim 4, wherein, in the heating step:

the core material layer cast ingot for rolling the B composite board is subjected to heating treatment at the temperature of 600 +/-20 ℃ in a heating furnace, and the heating time is 12-24 hours.

6. The method of claim 4, wherein the welding step is brazing in a controlled atmosphere furnace at 605 ± 15 ℃.

7. A battery comprising a water-cooled panel as claimed in any one of claims 1 to 3.

8. A new energy automobile comprising the battery according to claim 7.