A semi-solid extrusion aluminum battery shell thin wall forming method and forming system

Abstract

The present application relates to the technical field of aluminum extrusion battery shell, in particular to a semi-solid extrusion aluminum battery shell thin-wall forming method and forming system. The forming system comprises an extrusion die for extruding a first blank, one end of the extrusion die is provided with a pushing part for pushing an aluminum bar into the extrusion die, the end of the extrusion die away from the pushing part is provided with an ultrasonic detection part for obtaining defect data of the extruded first blank and uploading to a controller, the extrusion die has a cavity, a heating assembly is arranged around the cavity, the heating assembly is used for heating the cavity, the heating assembly comprises first heating modules arranged on four sides of the outer wall of the cavity, and second heating modules arranged at four corners of the cavity, a first temperature sensor is arranged at the first heating module, and a second temperature sensor is arranged at the second heating module. The present application can preferably produce thin-wall aluminum battery shell with stable structure and high performance, thereby reducing the weight of new energy battery shell.

Description

Technical Field

[0001] This invention relates to the field of aluminum extrusion battery casing technology, and more specifically, to a semi-solid extrusion aluminum battery casing thin-wall forming method and forming system. Background Technology

[0002] In recent years, with the rapid development of renewable energy and electric vehicles, aluminum batteries have broad application prospects in electric vehicles and portable electronic devices due to their excellent conductivity, lightweight and corrosion resistance.

[0003] Existing technology for producing thin-walled aluminum battery casings involves heating aluminum ingots to a semi-solid state and then cold-extruded them using a mold. During the cold-extruded process, the thin-walled material is prone to yielding under high pressure. When extruding aluminum battery casings with a thickness of less than 0.5mm, defects such as tearing and holes frequently occur due to insufficient material flow in the edge areas, affecting the integrity of the overall structure. Furthermore, the control of flatness is particularly important for thin-walled components. If the flatness of the casing fails to meet the design standards, it can easily lead to damage during subsequent assembly and use. Summary of the Invention

[0004] This invention provides a semi-solid extrusion aluminum battery casing thin-wall forming method, which can overcome some or all defects of the prior art to improve the structural integrity and flatness of the aluminum battery casing.

[0005] The semi-solid extruded aluminum battery casing thin-wall forming method according to the present invention includes:

[0006] The first forming stage includes: heating and melting aluminum ingots to obtain molten aluminum, and casting the molten aluminum to obtain aluminum rods; the second forming stage includes: performing at least one heating step to keep the aluminum rod in a semi-solid state, then cutting it and extruding it into an extrusion die for extrusion forming to obtain a first billet, wherein the extrusion die is heated during the extrusion process to keep the first billet in the extrusion die in a semi-solid state; the third forming stage includes: placing the first billet into a shaping die to perform a stretching and leveling step to obtain a second billet, performing a sawing step on the second billet, and allowing it to cool naturally after the sawing step, wherein the sawing step is performed using a laser cutting machine; the first post-processing stage includes: performing an aging step on the second billet to obtain a third billet; the second post-processing stage includes: performing an oxidation step on the third billet to obtain a battery casing.

[0007] Preferably, the first forming stage includes: heating the aluminum ingot to 700°C to obtain molten aluminum, pouring the molten aluminum into a casting mold for casting, and using circulating water to cool the casting mold during the casting process to form the aluminum rod.

[0008] Preferably, the second forming stage includes: heating the aluminum rod to 400°C to bring it into a semi-solid state, cutting the aluminum rod and extruding it into an extrusion mold for extrusion molding, and heating the cavity of the extrusion mold during the extrusion process.

[0009] Preferably, the aging step includes placing the second billet in an aging furnace and heating it to 180°C and holding it for 4 hours to eliminate stress concentration in the second billet.

[0010] Preferably, the oxidation step includes an alkaline etching step and an electro-oxidation step. The alkaline etching step uses sodium hydroxide solution to remove the thin oxide film on the surface of the third blank. Before performing the alkaline etching step, the blank is rinsed with water once, and after performing the alkaline etching step, it is rinsed with water a second time. After that, the blank is placed in a water tank and dilute sulfuric acid is added to neutralize the alkaline components on the surface of the third blank.

[0011] Preferably, the electro-oxidation step includes placing the alkaline-etched third blank as the anode in an electrolytic cell, adding 70% sulfuric acid to the electrolytic cell and reacting with electricity for 10 minutes to generate an oxide film on the surface of the third blank, and performing the electro-oxidation step 2-3 times.

[0012] The present invention also provides a semi-solid extruded aluminum battery casing thin-wall forming system, comprising: an extrusion die for extruding a first blank, a pushing part at one end of the extrusion die for pushing an aluminum rod into the extrusion die, an ultrasonic detection part at the end of the extrusion die away from the pushing part for acquiring defect data of the extruded first blank and uploading it to a controller, the extrusion die having a cavity, a heating assembly provided along the circumference of the cavity for heating the cavity, the heating assembly including a first heating module provided on the four sides forming the outer wall of the cavity, and a second heating module provided at the four corners of the cavity, a first temperature sensor provided at the first heating module, and a second temperature sensor provided at the second heating module.

[0013] Preferably, the controller includes: a data acquisition module for acquiring the pushing speed of the extruded aluminum rod in the propulsion section, temperature data from the first temperature sensor, and temperature data from the second temperature sensor; a data processing module for constructing an adjustment model and generating adjustment parameters based on the pushing speed of the extruded aluminum rod in the propulsion section, the temperature data from the first temperature sensor, the temperature data from the second temperature sensor, and defect data; and a control module for sending the adjustment parameters to the propulsion section, the first heating module, and the second heating module to adjust the pushing speed, the heating power of the first heating module, and the heating power of the second heating module.

[0014] As a preferred option, constructing the adjustment model includes the following steps:

[0015] S1: Place the aluminum rod into the propulsion section at the initial propulsion speed. It is pushed into the extrusion die, and the initial sidewall temperature of the extrusion die cavity is The initial edge temperature of the extrusion die cavity is The initial heating power of the first heating module is The initial heating power of the second heating module is ;

[0016] S2: The ultrasonic testing unit tests the first blank every 10 seconds to obtain defect data D;

[0017] S3: Based on the defect data D, calculate the adjustment parameters, the expression is:

[0018] (1)

[0019] in: To accelerate the new pace, At the current pace of progress, The propulsion speed adjustment coefficient caused by defective data. This represents the change in defect data. For the new sidewall temperature, This is the current sidewall temperature. The target molding temperature for the sidewalls. This is the sidewall temperature adjustment coefficient. For the new corner temperature, This is the current corner temperature. The target forming temperature for the corners, This is the corner temperature adjustment coefficient. For the power of the new first heating module, For the heating power of the new second module, This is the current power of the first heating module. This is the current heating power of the second module. This refers to the power adjustment coefficient of the first heating module based on the defect data. It is the power adjustment coefficient of the second heating module based on the defect data.

[0020] As a preferred option , , , and Obtained through the following steps:

[0021] Construct a multiple regression model, the expression of which is:

[0022] (2)

[0023] in For bias terms, The error term is obtained using the least squares method. , , , and .

[0024] Beneficial effects:

[0025] 1. This invention employs semi-solid extrusion technology, which allows aluminum to be formed in a semi-solid state, greatly improving forming efficiency and product quality. This process can effectively reduce material flow resistance and improve forming precision, thereby producing thinner-walled battery casings with better mechanical properties, thus better reducing the weight of new energy battery casings.

[0026] 2. By performing an aging step, the present invention can effectively eliminate stress concentration in the second blank, thereby improving the corrosion resistance and mechanical properties of the material and extending the service life of the battery casing.

[0027] 3. Through alkaline etching and electro-oxidation steps, the present invention can obtain a uniform and dense oxide film on the surface, which not only improves the corrosion resistance of the battery casing, but also enhances its insulation performance, thereby improving the safety and stability of the battery.

[0028] 4. In this invention, the propulsion unit can extrude the aluminum rod into the extrusion die, thereby extruding the first preform. The ultrasonic detection unit can detect the extruded first preform and obtain the defect data of the first preform. The temperature sensor can monitor the temperature inside the cavity, and the heating coil can control the heating power, thereby allowing the temperature inside the cavity to be adjusted as needed to improve the extrusion quality of the first preform.

[0029] 5. This invention can adjust the feed speed and cavity temperature in real time, thereby keeping the defect data D in a low range and thus improving the molding quality of the first blank. This system is applicable to aluminum alloy materials of various compositions. It automatically adjusts the feed speed and cavity temperature according to the above formula without manual intervention, thus improving production efficiency.

[0030] 6. The present invention changes the temperature of the sidewalls and corners of the cavity by changing the heating power of the first heating module and the second heating module, respectively. Therefore, the first heating module and the second heating module not only change the temperature of the cavity edge, but also control the temperature of the cavity sidewalls and corners. This can overcome the drawbacks of conventional aluminum battery shell extrusion dies, which are prone to defects such as local tearing and holes due to insufficient material flow in the edge area. Furthermore, by coupling multiple parameters, the pushing speed and the power of the first heating module and the second heating module can be adjusted and optimized in real time to further reduce the defects of the first blank. Attached Figure Description

[0031] Figure 1 Flowchart of a semi-solid extruded aluminum battery casing thin-wall forming method;

[0032] Figure 2 A schematic diagram of the components of a semi-solid extruded aluminum battery casing thin-wall forming system;

[0033] Figure 3 This is a schematic diagram of the controller module;

[0034] Figure 4 This is a first sectional view of the internal structure of the extrusion die cavity;

[0035] Figure 5 This is a second sectional view of the internal structure of the extrusion die cavity;

[0036] Figure 6 This is an isometric schematic diagram of a semi-solid extruded aluminum battery casing thin-wall forming system. Detailed Implementation

[0037] To further understand the content of this invention, the invention will be described in detail with reference to the embodiments. It should be understood that the embodiments are merely illustrative and not limiting of the invention.

[0038] Please refer to Figure 1 This solution provides a semi-solid extrusion aluminum battery casing thin-wall forming method, which can be used to produce thin-walled aluminum battery casings, including the following steps:

[0039] The first forming stage involves heating and melting aluminum ingots to obtain molten aluminum, which is then poured into aluminum rods. The aluminum ingots can be made of aluminum alloy materials such as 6061 or 6063, depending on the specific working conditions of the aluminum battery, to ensure their mechanical properties and corrosion resistance. Specifically, the aluminum ingots are heated to 700°C using a resistance furnace or high-frequency furnace to obtain molten aluminum, which is then poured into a casting mold. During the casting process, circulating water is used to cool the casting mold to form the aluminum rods.

[0040] The second forming stage involves performing at least one heating step, heating the aluminum rod to 400°C, keeping it in a semi-solid state, cutting it, and extruding it into an extrusion die to obtain the first blank. During the extrusion process, the extrusion die is heated to keep the first blank in the die in a semi-solid state. The aluminum rod is heated to 400°C to keep it in a semi-solid state before being cut and extruded. The semi-solid aluminum rod exhibits superior performance during the forming process, with better fluidity and higher forming precision. It can reduce defects such as pores and cracks during the forming process, thus improving the final structural integrity and surface quality of the aluminum battery casing.

[0041] Therefore, the above steps can effectively extrude a battery casing with a thickness of less than 0.4 mm, thereby reducing the overall weight of the new energy battery and playing an important role in the overall lightweighting of new energy batteries.

[0042] The third forming stage: The first blank is placed in a forming mold and stretched and leveled to obtain the second blank. The second blank is then sawed and allowed to cool naturally after sawing. The sawing process is performed using a laser cutting machine.

[0043] First post-processing stage: An aging step is performed on the second blank to obtain the third blank. The aging step includes heating the second blank to 180°C in an aging furnace and holding it for 4 hours to eliminate stress concentration in the second blank. Therefore, the aging step can improve the toughness and fatigue resistance of the material, reduce the risk of deformation and fracture during subsequent processing or use, thereby improving the service life and safety of the battery casing.

[0044] In addition, the above-mentioned aging treatment can also promote the homogenization of the internal structure and the refinement of the grains of the aluminum alloy, thereby improving the mechanical properties of the material and enabling the aluminum battery casing to better cope with the various mechanical loads generated by the battery during operation.

[0045] The second post-processing stage involves performing an oxidation step on the third blank to obtain the battery casing.

[0046] The oxidation step includes an alkaline etching step and an electro-oxidation step. The alkaline etching step uses sodium hydroxide solution to remove the thin oxide film on the surface of the third blank. Before performing the alkaline etching step, the blank is rinsed with water once, and after performing the alkaline etching step, it is rinsed with water a second time. After that, it is placed in a water tank and dilute sulfuric acid is added to neutralize the alkaline components on the surface of the third blank. The electro-oxidation step includes placing the alkaline-etched third blank as the anode in an electrolytic cell, adding 70% sulfuric acid to the electrolytic cell and reacting for 10 minutes to generate an oxide film on the surface of the third blank. The electro-oxidation step is performed 2-3 times.

[0047] The oxidation process combines alkaline etching and electro-oxidation, resulting in a layered surface treatment process for the battery casing. The alkaline etching step effectively removes the thin oxide film using sodium hydroxide solution, ensuring the uniformity and consistency of subsequent surface treatments.

[0048] Furthermore, water rinsing before and after the alkaline etching step effectively removes surface impurities and chemical residues, ensuring the efficiency and effectiveness of subsequent treatments. Then, dilute sulfuric acid is added for neutralization, further eliminating residual alkaline components and preventing negative impacts on subsequent oxide film formation. This precise neutralization control provides ideal pretreatment conditions for the electrolytic oxidation of aluminum, enhancing film adhesion.

[0049] During the electro-oxidation process, by using the third blank after alkaline etching as the anode and conductive graphite or other metals such as platinum as the cathode for electrolytic oxidation and performing the process 2-3 times, a more uniform and dense oxide film can be formed. This multiple oxidation treatment ensures the consistency and integrity of the oxide film in structure, improves the corrosion resistance and wear resistance of the battery casing, makes it not only insulating, but also improves the electrochemical stability of the aluminum alloy, enhances the ability of the electrolyte inside the battery to isolate and protect the internal components of the battery, and better extends the battery life.

[0050] Therefore, the above-mentioned treatment method can significantly improve the surface quality of the battery casing and reduce surface defects, thereby helping to enhance the overall performance of the battery casing. This is of great significance for ultra-thin battery casing materials below 0.4mm, as it can reduce the thickness of the battery casing without reducing the mechanical and electrochemical properties of the battery casing, thereby better reducing the overall weight of new energy batteries.

[0051] Seen in Figure 2-5 This solution also provides a semi-solid extrusion aluminum battery casing thin-wall forming system, which includes an extrusion die for extruding a first blank. One end of the extrusion die is provided with a pusher for pushing an aluminum rod into the extrusion die. The end of the extrusion die away from the pusher is provided with an ultrasonic detection unit for acquiring defect data of the extruded first blank and uploading it to a controller. The extrusion die has a cavity 23. A heating assembly 24 is provided around the cavity 23 for heating the cavity 23. The heating assembly 24 includes a first heating module 241 provided on the four sides of the outer wall of the cavity and a second heating module 242 provided at the four corners of the cavity 23. A first temperature sensor 251 is provided at the first heating module and a second temperature sensor 252 is provided at the second heating module.

[0052] According to the above scheme, the propulsion unit can extrude the aluminum rod into the extrusion die, thereby extruding the first blank. The ultrasonic detection unit can detect the extruded first blank and obtain the defect data of the first blank. The first temperature sensor 251 can monitor the temperature of the cavity sidewall, and the second temperature sensor 252 can monitor the temperature of the cavity corner. There are four of each of the second temperature sensors 251 and 252.

[0053] Furthermore, the first heating module and the second heating module 242 can control the heating power, thereby adjusting the temperature inside the cavity as needed to improve the extrusion quality of the first preform. Specifically, the first heating module 241 is responsible for heating the side walls around the cavity to reduce defects on the plane around the first preform, and the second heating module is responsible for heating the four corners of the cavity to reduce defects at the four corners of the first preform, thereby preventing defects such as tearing caused by insufficient material flow at the corners.

[0054] Understandably, the propulsion unit can employ a propulsion structure that allows for speed control, such as a pneumatic or hydraulic cylinder propulsion structure, a linear motor propulsion structure, or a lead screw propulsion structure. The extrusion die can be customized according to the size and thickness of the battery casing to be produced. The ultrasonic testing unit includes an ultrasonic detector, an ultrasonic generator, and a signal processing unit. The ultrasonic detector is used to emit and receive ultrasonic signals. Through the principle of ultrasonic reflection and refraction, the detector can identify the echo signals generated by defects, thereby determining the internal structural state of the material. The ultrasonic generator is used to generate ultrasonic signals of a certain frequency and transmit them to the aluminum billet to be tested. The signal processing unit can amplify and process the received echo signals to obtain defect data.

[0055] Seen in Figure 6 In this embodiment, the propulsion unit includes a linear motor 1, which includes a bracket 11 that moves along the length direction. The bracket 11 includes a clamping mechanism 12 for clamping an aluminum rod. One end of the extrusion die 2 is provided with an aluminum rod inlet 21 for inserting an aluminum rod. The aluminum rod is heated to a semi-solid state by a heating coil 24 inside the cavity 23 and extruded according to the shape of the battery casing to obtain a first blank. The end of the extrusion die 2 away from the aluminum rod inlet 21 is provided with a blank outlet 22. A conveying channel 3 is provided between the blank outlet 22 and the ultrasonic detection unit. The conveying channel 3 is used to convey the first blank extruded by the extrusion die to the ultrasonic detection unit. The ultrasonic detection unit includes an ultrasonic detector 4, which can detect and acquire defect data of the extruded first blank. The end of the ultrasonic detection unit away from the conveying channel 3 is provided with a discharge port 41.

[0056] The length of the conveying channel 3 is 80cm. After the first extruded billet is cooled by the conveying channel 3, it can be easily inspected by the ultrasonic testing unit to obtain more accurate defect data.

[0057] Please refer to Figure 2-3In some embodiments, the controller includes: a data acquisition module for acquiring the pushing speed of the extruded aluminum rod by the propulsion unit, temperature data from the first temperature sensor, and temperature data from the second temperature sensor; a data processing module for constructing an adjustment model and generating adjustment parameters based on the pushing speed of the extruded aluminum rod by the propulsion unit, the temperature data from the first temperature sensor 251, the temperature data from the second temperature sensor 252, and defect data; and a control module for sending the adjustment parameters to the propulsion unit, the first heating module 241, and the second heating module 242 to adjust the pushing speed, the heating power of the first heating module 241, and the heating power of the second heating module 242.

[0058] Specifically, constructing the adjustment model includes the following steps:

[0059] S1: Place the aluminum rod into the propulsion section at the initial propulsion speed. It is pushed into the extrusion die, and the initial sidewall temperature of the extrusion die cavity is The initial edge temperature of the extrusion die cavity is The initial heating power of the first heating module is The initial heating power of the second heating module is ;

[0060] S2: The ultrasonic testing unit tests the first blank every 10 seconds to obtain defect data D;

[0061] S3: Based on the defect data D, calculate the adjustment parameters, the expression is:

[0062] (1)

[0063] in: To accelerate the new pace, At the current pace of progress, The propulsion speed adjustment coefficient caused by defective data. This represents the change in defect data. For the new sidewall temperature, This is the current sidewall temperature. The target molding temperature for the sidewalls. This is the sidewall temperature adjustment coefficient. For the new corner temperature, This is the current corner temperature. The target forming temperature for the corners, This is the corner temperature adjustment coefficient. For the power of the new first heating module, For the heating power of the new second module, This is the current power of the first heating module. This is the current heating power of the second module. This refers to the power adjustment coefficient of the first heating module based on the defect data. It is the power adjustment coefficient of the second heating module based on the defect data.

[0064] Understandably, defect data D is generated by the ultrasonic testing unit and is used to evaluate the defects in the first blank, such as the number and depth of cracks. In practice, it can be further defined according to product process requirements, including the current sidewall temperature. The current corner temperature is the average of the temperature data from the four primary temperature sensors. This is the average of the temperature data from the four second temperature sensors.

[0065] By introducing the change in defect data It can track defects in the first blank during the production process in a timely manner, so as to make dynamic adjustments later, through automatically updated target molding temperature of the sidewall. and the target molding temperature of the edges and corners It can provide a better molding temperature reference in a short time, thereby avoiding large temperature fluctuations in the cavity, which would lead to large differences in the production quality of the first blank and improve product consistency.

[0066] Understandably, the target molding temperature for the sidewalls and the target molding temperature of the edges and corners These are the cavity sidewall temperature and cavity corner temperature when the defect data is at its lowest within 1 minute.

[0067] Therefore, by using feedback control based on the above multi-dimensional parameter adjustments, the sidewall forming temperature, corner forming temperature, and pushing speed can be controlled separately. This allows for real-time optimization of the pushing speed of the pushing part and the heating power of the first heating module 241 and the second heating module 242, thereby reducing the defect data D and ensuring the quality and stability of the first blank output.

[0068] Among them, the adjustment parameters , , , and Obtained through the following steps:

[0069] Construct a multiple regression model, the expression of which is:

[0070] (2)

[0071] in For bias terms, The error term is obtained using the least squares method. , , , and The above calculation process is carried out in the data processing module, and is performed in real time by writing computer programs.

[0072] Understandably, the bias term Sum of error terms By fitting specific experimental data generated during the installation and debugging of this molding system, the error in the normal working state of the molding system is reduced, thereby improving the accuracy of the feedback control of this molding system.

[0073] The above method can adjust the feed speed and the temperature of the cavity sidewalls (corners) in real time. By continuously processing the updated temperature and defect data, the defect data D is kept within a low range, thereby improving the molding quality of the first blank. Therefore, this system is applicable to aluminum alloy materials of various compositions. It can automatically adjust the feed speed and cavity temperature according to the above formula without manual intervention, thus improving production efficiency.

[0074] Specifically, by adjusting the heating power of the first heating module and the second heating module respectively, the forming quality of the first blank at the side wall and corners can be precisely controlled, thereby effectively reducing the number of defects in the first blank and improving the quality of the final aluminum battery casing.

[0075] In this embodiment, the cavity temperature is changed by changing the heating power of the first heating module and the second heating module. Therefore, the first heating module and the second heating module not only change the temperature at the edge of the cavity, but also indirectly control the temperature inside the cavity. This embodiment uses multiple parameters to couple and adjust and optimize the propulsion speed and the power of the first heating module 241 and the second heating module 242 in real time, so as to reduce the defects of the first blank.

[0076] Through the above steps, this semi-solid extrusion aluminum battery casing thin-wall forming system forms a closed-loop control. By using a multiple regression model to dynamically iterate various adjustment coefficients, aluminum ingots of any batch or grade can be put into production without experimentation, thus reducing production time and improving production efficiency. Furthermore, this system can automatically update data in real time to keep the defect rate of the first blank at a low level, thereby improving the forming quality of the first blank.

[0077] Therefore, this system can continuously optimize the extrusion strategy to address the defects in the first blank, thereby reducing the occurrence of defects and improving the overall performance of the finished aluminum battery casing.

[0078] Furthermore, this model allows for dynamic adjustment of operating parameters based on real-time detection data, making the extrusion process more flexible and adaptable to various production conditions and material properties. This solution achieves this by setting bias terms. Sum of error terms This method enables the model to adapt to and compensate for abnormal fluctuations in historical data, providing more accurate adjustments. As a result, the control becomes more stable, reducing production fluctuations caused by sudden defects.

[0079] Furthermore, by optimizing the propulsion speed and heating power, the energy consumption of linear motor 1 and heating group 24 can be reduced. In addition, this solution can reduce the scrap rate, thereby reducing the consumption of aluminum rods and has better economic efficiency.

[0080] The following are several sets of specific experimental data for producing aluminum battery casings with a thickness ∈ [0.2, 0.4] mm using this semi-solid extrusion aluminum battery casing thin-wall forming system:

[0081]

[0082] Tensile strength and compressive strength: characterize the performance of the aluminum battery casing during tensile and compressive processes, representing its strength.

[0083] Elongation: This indicates the extent to which an aluminum battery casing can extend before it breaks, and is an important indicator for judging its toughness.

[0084] Corrosion resistance: After immersion in a corrosive solution for 24 hours, the thickness of the aluminum battery casing is measured by the depth of the area with the greatest corrosion loss. The smaller the value, the better the corrosion resistance.

[0085] Defect rate: This represents the percentage of defective products out of the total sample during the sample production process.

[0086] In the corrosion resistance test, the corrosive medium was 9.5% dilute sulfuric acid.

[0087] The experimental data above shows that the battery casings with a thickness of less than 0.4mm produced using this semi-solid extruded aluminum battery casing thin-wall forming system all meet the requirements for the use of new energy batteries in terms of tensile strength, compressive strength, elongation, and corrosion resistance, and the defect rate is within the normal range.

[0088] Therefore, this system can effectively improve the production quality of thin-walled aluminum battery casings, making it better suited for the field of new energy batteries. By providing high-quality thin-walled aluminum battery casings, it reduces the weight of new energy batteries, thereby achieving lightweighting of new energy equipment.

[0089] It is readily understood that those skilled in the art can combine, split, or reorganize the embodiments provided in this application to obtain other embodiments, all of which do not exceed the protection scope of this application.

[0090] The present invention and its embodiments have been described above illustratively. This description is not restrictive, and the embodiments shown are only part of the embodiments of the present invention. The actual structure is not limited thereto. Therefore, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the spirit of the present invention, they should all fall within the protection scope of the present invention.

Claims

1. A semi-solid extruded aluminum battery casing thin-wall forming system, characterized in that, include: An extrusion die is used to extrude a first blank. One end of the extrusion die is provided with a pusher section for pushing an aluminum rod into the extrusion die. The end of the extrusion die away from the pusher section is provided with an ultrasonic detection section for acquiring defect data of the extruded first blank and uploading it to a controller. The extrusion die has a cavity. A heating assembly is provided along the circumference of the cavity for heating the cavity. The heating assembly includes a first heating module located on the four sides forming the outer wall of the cavity and a second heating module located at the four corners of the cavity. A first temperature sensor is provided at the first heating module and a second temperature sensor is provided at the second heating module. The controller includes: Data acquisition module: used to collect the pushing speed of the extruded aluminum rod in the propulsion section, the temperature data of the first temperature sensor and the temperature data of the second temperature sensor; Data processing module: Constructs an adjustment model and generates adjustment parameters based on the pushing speed of the extruded aluminum rod in the propulsion section, the temperature data of the first temperature sensor, the temperature data of the second temperature sensor, and defect data; Control module: Used to send adjustment parameters to the propulsion unit, the first heating module, and the second heating module to adjust the propulsion speed, the heating power of the first heating module, and the heating power of the second heating module; Constructing a regulation model involves the following steps: S1: Place the aluminum rod into the propulsion section at the initial propulsion speed. It is pushed into the extrusion die, and the initial sidewall temperature of the extrusion die cavity is The initial edge temperature of the extrusion die cavity is The initial heating power of the first heating module is The initial heating power of the second heating module is ; S2: The ultrasonic testing unit tests the first blank every 10 seconds to obtain defect data D; S3: Based on the defect data D, calculate the adjustment parameters, the expression is: （1） in: To accelerate the new pace, At the current pace of progress, The propulsion speed adjustment coefficient caused by defective data. This represents the change in defect data. For the new sidewall temperature, This is the current sidewall temperature. The target molding temperature for the sidewalls. This is the sidewall temperature adjustment coefficient. For the new corner temperature, This is the current corner temperature. The target forming temperature for the corners, This is the corner temperature adjustment coefficient. For the power of the new first heating module, For the heating power of the new second module, This is the current power of the first heating module. This is the current heating power of the second module. This refers to the power adjustment coefficient of the first heating module based on the defect data. It is the power adjustment coefficient of the second heating module based on the defect data.

2. The semi-solid extruded aluminum battery casing thin-wall forming system according to claim 1, characterized in that, , , , and Obtained through the following steps: Construct a multiple regression model, the expression of which is: （2） in For bias terms, The error term is obtained using the least squares method. , , , and .

3. The semi-solid extruded aluminum battery casing thin-wall forming system according to claim 1, characterized in that, The forming method of the semi-solid extruded aluminum battery casing thin-wall forming system includes: The first forming stage includes: heating and melting aluminum ingots to obtain molten aluminum, and casting the molten aluminum to obtain aluminum rods; The second forming stage includes: performing at least one heating step to keep the aluminum rod in a semi-solid state, then cutting it and extruding it into an extrusion die for extrusion forming to obtain the first blank. During the extrusion process, the extrusion die is heated so that the first blank in the extrusion die is in a semi-solid state. The third forming stage includes: placing the first blank into a forming mold and performing a stretching and leveling step to obtain the second blank; performing a sawing step on the second blank; and allowing the second blank to cool naturally after the sawing step. The sawing step is performed using a laser cutting machine. The first post-processing stage includes: performing an aging step on the second blank to obtain the third blank; The second post-processing stage includes: performing an oxidation step on the third preform to obtain the battery casing.

4. The semi-solid extruded aluminum battery casing thin-wall forming system according to claim 3, characterized in that, The first molding stage includes: Aluminum ingots are heated to 700°C to obtain molten aluminum. The molten aluminum is then poured into a casting mold for casting. During the casting process, circulating water is used to cool the casting mold so that the aluminum rod can be formed.

5. The semi-solid extruded aluminum battery casing thin-wall forming system according to claim 3, characterized in that, The second molding stage includes: The aluminum rod is heated to 400°C, making it semi-solid. The rod is then cut and extruded into an extrusion mold for molding. The cavity of the extrusion mold is heated during the extrusion process.

6. The semi-solid extruded aluminum battery casing thin-wall forming system according to claim 3, characterized in that, The aging step includes placing the second billet in an aging furnace and heating it to 180°C and holding it for 4 hours to eliminate stress concentration in the second billet.

7. The semi-solid extruded aluminum battery casing thin-wall forming system according to claim 3, characterized in that, The oxidation step includes an alkaline etching step and an electro-oxidation step. In the alkaline etching step, sodium hydroxide solution is used to remove the thin oxide film on the surface of the third blank. Before performing the alkaline etching step, the blank is rinsed with water once, and after performing the alkaline etching step, it is rinsed with water a second time. After that, it is placed in a water tank and dilute sulfuric acid is added to neutralize the alkaline components on the surface of the third blank.

8. The semi-solid extruded aluminum battery casing thin-wall forming system according to claim 7, characterized in that, The electro-oxidation step includes placing the alkaline-etched third blank as the anode in an electrolytic cell, adding 70% sulfuric acid to the electrolytic cell and reacting with electricity for 10 minutes to generate an oxide film on the surface of the third blank. The electro-oxidation step is performed 2-3 times.

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