High-performance aluminum foil material and preparation method thereof

Abstract

The invention relates to the technical field of aluminum foil preparation, in particular to a high-performance aluminum foil material and a preparation method thereof.The method comprises the steps that molten aluminum is put into a refining furnace to be refined in the mode that active gas and inert gas are mixed; casting and rolling the refined molten aluminum by adopting a casting and rolling machine; the aluminum plate obtained after cast rolling is subjected to cold rolling including first cold rolling and second cold rolling, and an aluminum foil semi-finished product is obtained; two times of annealing are performed after the first time of cold rolling; the aluminum foil semi-finished product is subjected to finish rolling, and in the finish rolling process, the flatness of all preset positions of the aluminum foil semi-finished product at all moments is collected; measuring stress and rolling force of each position and each moment of the aluminum foil semi-finished product; the flatness of the aluminum foil semi-finished product at each moment in the finish rolling process is obtained; based on the error between the flatness of the aluminum foil semi-finished product at each moment in the finish rolling process and the target flatness, the rolling force at each moment in the finish rolling process is regulated and controlled; and the aluminum foil material is obtained after finish rolling. Therefore, the performance of the aluminum foil material is improved.

Description

Technical Field

[0001] The present application relates to the technical field of aluminum foil preparation, and in particular to a high-performance aluminum foil material and a preparation method thereof. Background Art

[0002] Double-zero aluminum foil refers to aluminum foil with two zeros after the decimal point when the thickness is measured in millimeters, usually less than 0.0075mm thick. As a high-performance aluminum foil material, double-zero aluminum foil has better flexibility and plasticity, and can better wrap items of various shapes; it has good tear resistance and wear resistance, and is not easy to break; it also has excellent barrier properties and high temperature resistance.

[0003] However, in the production process of double-zero aluminum foil, the flatness of the aluminum plate has a significant impact on the performance of the double-zero aluminum foil, and the flatness of the aluminum plate directly affects the stability of the rolling process. If there is a large flatness deviation in the aluminum plate, it may cause uneven deformation of the aluminum plate, resulting in local stretching or compression of the metal, resulting in uneven tensile properties and mechanical strength of the aluminum foil. Since the uneven aluminum plate will form stress concentration during the rolling process, the strength of certain areas of the aluminum foil is uneven, resulting in lower performance of the aluminum foil. Therefore, the flatness of the aluminum plate needs to be strictly controlled during the production process to ensure the excellent performance and quality of the aluminum foil. Summary of the invention

[0004] In order to solve the above technical problems, the purpose of this application is to provide a high-performance aluminum foil material and a preparation method thereof. The technical solutions adopted are as follows: In a first aspect, an embodiment of the present application provides a method for preparing a high-performance aluminum foil material, the method comprising the following steps: The raw materials include iron, silicon, titanium, copper, magnesium, manganese, zinc and aluminum. All the raw materials are placed in a smelting furnace according to a set weight percentage to prepare aluminum liquid, and the aluminum liquid is placed in a refining furnace for refining; The refined aluminum liquid is sequentially subjected to cast rolling and cold rolling, wherein the cold rolling includes a first cold rolling and a second cold rolling, to obtain an aluminum foil semi-finished product; wherein, the first cold rolling is followed by two annealing steps; The aluminum foil semi-finished product is subjected to finish rolling. During the finish rolling process, the flatness of each preset position of the aluminum foil semi-finished product at each time is collected; the stress and rolling force of each position of the aluminum foil semi-finished product at each time are measured; The aluminum foil semi-finished product is evenly divided into grid units, and based on the distribution of stress at all positions in each grid unit at each time, all grid units at each time are divided into a plurality of stress regions; Analyze the change rate of stress at all positions in each grid unit at each moment, and combine the preset weight of each grid unit at each moment to obtain the stress distribution factor of each grid unit at each moment; The correlation between the stress and rolling force of all grid units belonging to each stress area at each moment is analyzed respectively, and the strain weights of all grid units belonging to each stress area at each moment are obtained. Combined with the stress distribution factor, the mean flatness of all preset positions in each grid unit at each moment is corrected to obtain the flatness of the aluminum foil semi-finished product at each moment during the finishing rolling process; Based on the error between the flatness and the target flatness, a control algorithm is used to regulate the rolling force at each moment during the finishing rolling process; After fine rolling, aluminum foil material is obtained.

[0005] In one embodiment, the weight percentage of the raw material components is: Si: 0.10~0.13%, Fe: 0.40~0.45%, Cu: 0.01%, Mn: 0.01%, Mg: 0.005%, Zn: 0.03%, Ti: 0.01~0.03%, Al: 99.35%.

[0006] In one embodiment, the refining is performed by mixing active gas and inert gas, wherein the active gas is chlorine gas, and the addition amount is 5% to 10% of the aluminum melt; the inert gas is argon gas, and the flow rate of argon gas is controlled at 10 to 20 L / min.

[0007] In one embodiment, the refining uses a mixed solvent of NaCl and KCl, wherein the ratio of NaCl to KCl is between 40:60 and 60:40, the amount of the mixed solvent added is 2% to 5% of the aluminum liquid, the refining time is 30 to 60 minutes, and the refining agent used is Al.

[0008] In one embodiment, the casting temperature is 685-695°C, the casting speed is 850-1050 mm / min, the length of the casting zone is 55-65 mm, the cooling water flow rate is 100-150 m³ / h, the inlet and outlet water temperature difference is 10-15°C, and the liquid level is 550-650 mm; The thickness of the aluminum plate after casting and rolling is 3-8 mm.

[0009] In one embodiment, the thickness of the aluminum plate after the first cold rolling is 0.2~0.4mm, the thickness of the aluminum foil semi-finished product after the second cold rolling is 0.012~0.028mm, the temperature of the first annealing in the two annealings is 420~440℃, the time is 5~8 hours, and the grain diameter after the first annealing is less than or equal to 0.12mm, the temperature of the second annealing is 380~420℃, the time is 5~8 hours, and the grain diameter after the second annealing is less than or equal to 0.09mm.

[0010] In one embodiment, dividing all grid cells at each moment into a plurality of stress regions includes: Calculate the mean value and dispersion degree of the modulus value of stress at all positions of the aluminum foil semi-finished product at each moment, take the sum of the mean value of the modulus value and the dispersion degree as the first threshold, and take the difference between the mean value of the modulus value and the dispersion degree as the second threshold; The mean of the modulus values ​​of stress at all positions in each grid unit at each moment is calculated and recorded as the first mean value. The grid units whose first mean value is greater than the first threshold value are regarded as high stress areas, the grid units whose first mean value is less than the second threshold value are regarded as low stress areas, and the grid units other than the high stress areas and the low stress areas are regarded as medium stress areas.

[0011] In one embodiment, the determination of the stress distribution factor includes: Based on the stress at all positions in each grid unit, the composite stress of each grid unit is obtained, and the gradient of the composite stress of each grid unit is calculated, wherein the stress distribution factor is a fusion result of the modulus of the gradient and the preset weight; Determination of the strain weights of all mesh cells belonging to the high stress zone includes: forming the modules of the rolling force of all mesh cells belonging to the high stress zone into a first sequence, forming the modules of the synthetic stress of all mesh cells belonging to the high stress zone into a second sequence, and the strain weight is the correlation between the first sequence and the second sequence.

[0012] In one embodiment, the determination of the flatness of the semi-finished aluminum foil product at each moment during the finishing rolling process includes: Calculate the normalized result of the product of the stress distribution factor of each grid unit and the corresponding strain weight, calculate the mean of the flatness of all preset positions in each grid unit, record it as the second mean, calculate the multiplication result of the normalized result of each grid unit and the second mean, and the flatness of the aluminum plate at each moment is the mean of the multiplication results of all grid units at each moment; The thickness of the aluminum foil material obtained after the finish rolling is 0.0042-0.006 mm.

[0013] In a second aspect, the embodiments of the present application also provide a high-performance aluminum foil material, which is prepared using any of the preparation methods described above.

[0014] This application has at least the following beneficial effects: The present application puts aluminum liquid into a refining furnace and refines it by mixing active gas and inert gas; casts the refined aluminum liquid by a casting and rolling mill; cold-rolls the aluminum plate obtained after casting and rolling, and the cold rolling includes a first cold rolling and a second cold rolling to obtain an aluminum foil semi-finished product; wherein, the first cold rolling is followed by two annealings; the aluminum foil semi-finished product is finish-rolled, and during the finish-rolling process, the flatness of each preset position of the aluminum foil semi-finished product at each time is collected; the stress and rolling force of each position of the aluminum foil semi-finished product at each time are measured; the aluminum foil semi-finished product is evenly divided into each grid unit. Based on the stress distribution of all positions in each grid unit at each moment, all grid units at each moment are divided into high stress area, medium stress area and low stress area; by dividing the aluminum foil semi-finished product into regions, the accuracy of subsequent stress analysis is improved, and higher attention is paid to the high stress area; the stress change rate of all positions in each grid unit at each moment is analyzed, and the stress distribution factor of each grid unit at each moment is obtained by combining the preset weight of each grid unit at each moment; the stress distribution factor reflects the overall distribution of stress in each grid unit, which indirectly reflects the stress distribution at this moment. The adaptability of rolling force during cold rolling improves the reliability of rolling force regulation during finishing rolling; the correlation between stress and rolling force of all grid units belonging to high stress area at each moment is analyzed to obtain strain weights of all grid units belonging to high stress area at each moment, and correspondingly, the strain weights of all grid units belonging to medium stress area and low stress area at each moment are obtained; the strain weight reflects the mutual influence relationship between stress and rolling force of grid units, and improves the accuracy of rolling force regulation; combined with the stress distribution factor and strain weight of each grid unit at each moment, the mean flatness of all preset positions in each grid unit at each moment is corrected to obtain the flatness of aluminum foil semi-finished products at each moment during finishing rolling; the problem of different stresses in different areas of aluminum foil semi-finished products causing errors in flatness measurement is avoided, and the accuracy of flatness measurement of aluminum foil semi-finished products is improved; based on the error between the flatness of aluminum foil semi-finished products at each moment during finishing rolling and the target flatness, the rolling force at each moment during finishing rolling is regulated by control algorithm; the rationality and accuracy of rolling force regulation are improved; aluminum foil material is obtained after finishing rolling, and the performance of aluminum foil material is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present application or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0016] Figure 1 A flowchart of a method for preparing a high-performance aluminum foil material provided in one embodiment of the present application; Figure 2 Schematic diagram of the flatness of aluminum foil material. DETAILED DESCRIPTION

[0017] In order to further explain the technical means and effects adopted by the present application to achieve the predetermined invention purpose, the following is a detailed description of a high-performance aluminum foil material and its preparation method proposed in the present application, its specific implementation method, structure, characteristics and effects, in combination with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "another embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures or characteristics in one or more embodiments may be combined in any suitable form.

[0018] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0019] The specific scheme of a high-performance aluminum foil material and a preparation method thereof provided by the present application is described in detail below with reference to the accompanying drawings.

[0020] Example 1 See also Figure 1 , which shows a flow chart of the steps of a method for preparing a high-performance aluminum foil material provided in Example 1 of the present application, the method comprising the following steps: S1, putting the aluminum liquid into a refining furnace and refining it by mixing active gas and inert gas.

[0021] The raw materials for preparing the aluminum foil material in this embodiment include: Si: 0.10-0.13%, Fe: 0.40-0.45%, Cu: 0.01%, Mn: 0.01%, Mg: 0.005%, Zn: 0.03%, Ti: 0.01-0.03%, Al: 99.35%. All the raw materials are put into a smelting furnace according to their weight percentages for smelting to obtain aluminum liquid; the aluminum liquid may contain inevitable impurities.

[0022] Then the aluminum liquid is put into the refining furnace for refining. This embodiment uses a mixed refining method of active gas plus inert gas to achieve the best purification effect. The active gas is chlorine, and the amount of chlorine added is 5% of the aluminum melt. The aluminum chloride gas generated by the reaction between chlorine and the aluminum melt can effectively remove hydrogen and some fine inclusions. In addition to reacting with aluminum to generate aluminum chloride, chlorine also reacts with hydrogen in the melt to generate HCl. This reaction is rapid and degassing is fast. Therefore, chlorine refining has the effects of both physical degassing and chemical degassing, and the refining effect is relatively good. The inert gas is argon, and the flow rate of argon is controlled at 10L / min. Its inertness and good stirring effect are used to promote the floating removal of gas and inclusions in the aluminum liquid.

[0023] In the process of aluminum liquid refining, the solvent used is NaCl-KCl series flux. In this embodiment, the ratio of NaCl to KCl is 40:60, the amount of NaCl-KCl series flux added is 2% of the aluminum melt, the refining agent used is Al, the amount of refining agent added is 2kg / t, and the refining process lasts for 30 minutes. During this period, a strong agitator is required to ensure that the refining agent is evenly dispersed in the aluminum liquid to give full play to its purification effect.

[0024] S2, the refined aluminum liquid is cast-rolled by a casting and rolling mill; the aluminum plate obtained after the casting and rolling is cold-rolled, and the cold rolling includes a first cold rolling and a second cold rolling to obtain an aluminum foil semi-finished product; wherein, two annealings are performed after the first cold rolling.

[0025] The refined aluminum liquid flows into the front box of the casting and rolling mill. In this embodiment, the liquid level height of the front box of the casting and rolling mill is 550mm, and the liquid level height of the front box needs to be accurately controlled within the range of ±2mm. The roller diameter is 800mm, the casting and rolling zone length is 55mm, the casting and rolling temperature is 685℃, and the casting and rolling speed is 850mm / min.

[0026] The cooling intensity during the casting and rolling process is achieved by controlling the flow rate of cooling water inside the roll and the temperature difference between the inlet and outlet water. The cooling water flow rate is 100m³ / h, and the inlet and outlet water temperature difference is maintained at 10°C to ensure that the surface temperature of the roll is uniform and stable, so that the aluminum liquid solidifies and crystallizes at a suitable cooling rate to obtain good structure and performance.

[0027] The thickness of the aluminum plate obtained after aluminum liquid casting is 8mm.

[0028] Then, the cast aluminum plate is cold rolled using a single-stand rolling mill. The cold rolling is divided into two times, namely the first cold rolling and the second cold rolling. The distribution of the pass processing rate is a key link in the cold rolling process. The first pass processing rate is accurately set according to the slab thickness and alloy properties. During the first cold rolling, the first pass processing rate in this embodiment is 22%, and the subsequent pass processing rates gradually decrease. The decreasing range is determined according to the work hardening characteristics of the alloy and the final thickness requirements of the product. In this embodiment, each pass decreases by 2%, and the number of cold rolling passes is 8.

[0029] During the second cold rolling, the processing rate of the first pass is 21%, and the processing rate of the subsequent passes decreases gradually. In this embodiment, each pass decreases by 2%, and the number of cold rolling passes is 6.

[0030] The thickness of the aluminum plate obtained after the first cold rolling is 0.4 mm. The aluminum plate obtained after the first cold rolling is recorded as the first aluminum plate. The first aluminum plate is annealed twice. The temperature of the first annealing is 420°C and the time is 5 hours. After the first annealing, the grain diameter is less than or equal to 0.12 mm. The temperature of the second annealing is 380°C and the time is 5 hours. After the second annealing, the grain diameter is less than or equal to 0.09 mm.

[0031] The aluminum sheet after the second cold rolling is recorded as an aluminum foil semi-finished product, and the thickness of the aluminum foil semi-finished product is 0.028 mm.

[0032] S3, finishing rolling the aluminum foil semi-finished product. During the finishing rolling process, the flatness of each preset position of the aluminum foil semi-finished product at each moment is collected; and the stress and rolling force of each position of the aluminum foil semi-finished product at each moment are measured.

[0033] The obtained aluminum foil semi-finished product is subjected to finish rolling, which is also cold rolling. There are 4 finish rolling passes, the processing rate of the first pass is 20%, and the processing rate of subsequent passes gradually decreases. In this embodiment, each pass decreases by 2%. During the finish rolling process, a SI-FLAT non-contact plate shape meter is installed along the width direction of the aluminum foil semi-finished product on the outlet side of the cold rolling mill. Since the stress in the central part of the width direction of the aluminum foil semi-finished product changes slowly, while the stress in the edge part changes greatly, this embodiment uses the central position of the width direction of the aluminum foil semi-finished product as a reference point, and distributes sensors from the reference point to both sides in sequence, wherein the spacing of the first 10 sensors is 60 mm, the spacing of the next 50 sensors is 30 mm, and the spacing of the last 50 sensors is 15 mm. The SI-FLAT non-contact plate shape meter has a total of 110 sensors, and each sensor collects the flatness of the corresponding position respectively.

[0034] It should be noted that no sensor is installed at the center position in the width direction of the aluminum foil semi-finished product. The number of sensors installed and the spacing between sensors can be set by the implementer according to the actual situation. It is only necessary to ensure that the spacing between sensors close to the reference point is larger, followed by the middle, and the spacing between sensors close to the edge is the smallest. The first 10 sensors are 5 sensors on the left and right sides of the reference point respectively, and the next 50 sensors and the last 50 sensors are distributed in the same way as the first 10 sensors.

[0035] Secondly, during the finishing rolling process, N laser interferometers are installed at equal intervals above the aluminum foil semi-finished product along its width direction to measure the stress at the corresponding position of each laser interferometer on the aluminum foil semi-finished product. In this embodiment, N=10, which can be set by the implementer according to the actual situation, and this embodiment does not limit it. A mechanical sensor is installed in the cold rolling mill to collect the rolling force at each moment in the cold rolling process in real time. Since the rolling process is dynamic, the rolling force at each moment corresponds to each position on the aluminum foil semi-finished product.

[0036] In this embodiment, flatness, stress, and rolling force are all collected synchronously, and the collection frequency is 10 Hz, which can be set by the implementer according to the actual situation.

[0037] S4, evenly dividing the aluminum foil semi-finished product into grid units, and based on the distribution of stress at all positions in each grid unit at each moment, dividing all grid units at each moment into a high stress area, a medium stress area and a low stress area.

[0038] During the rolling process, the flatness of the aluminum plate will change, resulting in the aluminum plate not meeting the requirements. The uneven distribution of rolling force is the key factor. If the rollers are worn to different degrees, the pressure on the aluminum plate during cold rolling will be inconsistent, resulting in uneven force on the plate in the width direction, which in turn causes flatness changes. For example, when the middle part of the roller is severely worn, the middle part of the aluminum plate is under great pressure, which is prone to convexity.

[0039] Therefore, during the cold rolling process, the rolling force is closely related to the flatness of the aluminum plate. When the rolling force changes, it will directly affect the stress distribution inside the aluminum plate, thereby changing the deformation of the aluminum plate, which is ultimately reflected in the flatness of the aluminum plate. Because a larger rolling force will cause the plate to undergo greater plastic deformation during the cold rolling process. If the rolling force is uneven, for example, if the degree of roller wear is inconsistent or the rolling process parameters are improperly set, the aluminum plate will deform unevenly in the width direction. In this case, some areas of the aluminum plate may be over-extruded while other areas are under-deformed, resulting in stress concentration and causing aluminum plate defects such as edge waves, convex or concave, which deteriorates the flatness.

[0040] In actual production, the rolling force can be adjusted according to the change in the flatness of the aluminum plate. Because flatness is an intuitive reflection of the quality of the aluminum plate shape, the flatness index of the aluminum plate is monitored in real time. When the flatness is detected to be beyond the predetermined standard range, it means that there is a problem with the shape of the aluminum plate, which is likely caused by unreasonable rolling force. At this time, the deformation of the aluminum plate can be improved by adjusting the amount of roller pressure or the size of the rolling force, so that the flatness is restored to the qualified range. For example, if the aluminum plate has a convex plate shape defect, it means that the rolling force on the middle part of the aluminum plate is too large. The amount of roller pressure or the overall rolling force can be appropriately reduced to make the deformation of the plate in the width direction more uniform, thereby improving the flatness of the aluminum plate, thereby achieving the purpose of plate shape control.

[0041] However, most of the existing technologies ignore the fact that the deformation at different positions has different effects on the plate shape, resulting in errors in the collection of flatness, which in turn affects the control of rolling force during cold rolling. During the cold rolling process, when the longitudinal fibers of the aluminum foil show uneven elongation in the width direction, the fibers pull each other due to the difference in elongation, thereby generating internal stress, namely residual stress. The distribution of this residual stress in the transverse direction of the plate and strip is non-equilibrium, with tensile stress and compressive stress coexisting. When the compressive stress borne by a certain area in the transverse direction exceeds the critical yield stress threshold of the aluminum plate itself, the aluminum plate will deform; on the contrary, if the threshold is not reached, although no deformation has occurred, there is still uneven stress inside. Therefore, by calculating the weight of the stress change of the plate during cold rolling, the stress change at different positions of the aluminum plate can be better reflected.

[0042] Based on the above analysis, this embodiment firstly divides the aluminum foil semi-finished product into M grid units uniformly, calculates the mean and dispersion degree of the modulus values ​​of the stress at all positions of the aluminum foil semi-finished product at each moment, takes the sum of the mean value of the modulus value and the dispersion degree as the first threshold, and takes the difference between the mean value of the modulus value and the dispersion degree as the second threshold; Then, the mean of the modulus values ​​of stress at all positions in each grid unit at each moment is calculated and recorded as the first mean value. The grid units whose first mean value is greater than the first threshold value are regarded as high stress areas, the grid units whose first mean value is less than the second threshold value are regarded as low stress areas, and the grid units other than the high stress areas and the low stress areas are regarded as medium stress areas.

[0043] It should be noted that in this embodiment, M=20, which can be set by the implementer according to the actual situation. The calculation method of the discrete degree is the standard deviation, and the implementer can choose other existing feasible discrete degree calculation methods, such as variance, coefficient of variation, etc.

[0044] S5, analyzing the change rate of stress at all positions in each grid unit at each moment, and combining the preset weight of each grid unit at each moment to obtain the stress distribution factor of each grid unit at each moment.

[0045] When controlling the shape of aluminum plates, areas with high stress are often high-incidence areas of quality problems. For example, in the production of aluminum foil, stress concentration areas are prone to defects such as cracks and wrinkles. Giving these areas with high stress a larger weight can make quality control more focused on these key areas. Set basic weights for different stress areas. In this embodiment, the basic weight of the grid cells belonging to the high stress area is 0.5, the basic weight of the grid cells belonging to the medium stress area is 0.3, and the basic weight of the grid cells belonging to the low stress area is 0.2.

[0046] Secondly, the stress distribution factor of each grid unit at each moment is calculated, specifically: based on the stress at all positions in each grid unit, the composite stress of each grid unit is obtained, and the gradient of the composite stress of each grid unit is calculated, and the stress distribution factor is the fusion result of the modulus of the gradient and the preset weight; It should be understood that fusion means combining multiple variables, which can be specifically achieved by addition, multiplication, or a combination of addition and multiplication.

[0047] In this embodiment, at each moment, all stresses measured in each grid unit are synthesized by force to obtain the synthetic stress of each grid unit, and the gradient of the synthetic stress of each grid unit is calculated, and the stress distribution factor is the product of the modulus of the gradient and its corresponding basic weight. Among them, the synthesis of force and the calculation of the gradient are existing well-known technologies.

[0048] S6, analyzing the correlation between the stress and rolling force of all grid cells belonging to the high stress zone at each moment, obtaining the strain weights of all grid cells belonging to the high stress zone at each moment, and correspondingly, obtaining the strain weights of all grid cells belonging to the medium stress zone and the low stress zone at each moment.

[0049] During the cold rolling process, there is a close mutual influence relationship between rolling force and stress. Rolling force is an important external factor that causes stress in the plate. When the rolling force acts on the plate, the plate will undergo plastic deformation. According to the mechanical properties and deformation law of the material, this deformation will induce stress inside the plate. For example, in the early stage of cold rolling, as the rolling force gradually increases, the stress inside the plate will also increase accordingly. A large rolling force will cause the fiber structure of the plate to deform by stretching, compression and bending, thereby generating a complex stress state, including longitudinal stress, transverse stress and shear stress.

[0050] The distribution and magnitude of stress will in turn affect the cold rolling process. If the stress distribution inside the plate is uneven, such as the presence of local stress concentration, the deformation behavior of the plate during the cold rolling process will change. The material in the stress concentration area may reach the yield limit earlier and deform excessively, which may cause plate shape defects such as edge waves, convex or concave. These plate shape defects will further affect the distribution of rolling force, making the rolling force no longer uniform in the width direction of the plate, exacerbating the unevenness of stress.

[0051] In actual production, this mutual influence requires precise control of rolling force to obtain reasonable stress distribution and ensure the quality of the plate. At the same time, by monitoring the changes in stress, the rolling force can be adjusted in time to maintain a stable cold rolling process and achieve effective control of the plate shape and performance.

[0052] Therefore, for each moment, this embodiment forms the modules of the rolling force of all grid cells belonging to the high stress zone into a first sequence, forms the modules of the synthetic stress of all grid cells belonging to the high stress zone into a second sequence, and calculates the correlation between the first sequence and the second sequence as the strain weight of all grid cells belonging to the high stress zone at each moment.

[0053] The correlation described in this embodiment is calculated using the Pearson correlation coefficient, and the implementer can choose other similarity calculation methods, such as cosine similarity, etc.

[0054] For each moment, this embodiment forms the modules of the rolling force of all the grid units belonging to the medium stress zone into a third sequence, forms the modules of the composite stress of all the grid units belonging to the medium stress zone into a fourth sequence, and calculates the correlation between the third sequence and the fourth sequence as the strain weights of all the grid units belonging to the medium stress zone at each moment; For each moment, this embodiment forms the modules of the rolling force of all grid units belonging to the low stress zone into a fifth sequence, forms the modules of the composite stress of all grid units belonging to the low stress zone into a sixth sequence, and calculates the correlation between the fifth sequence and the sixth sequence as the strain weight of all grid units belonging to the low stress zone at each moment.

[0055] S7, combining the stress distribution factor and strain weight of each grid unit at each moment, correcting the mean flatness of all preset positions in each grid unit at each moment, and obtaining the flatness of the aluminum foil semi-finished product at each moment during the finishing rolling process.

[0056] This embodiment corrects the flatness mean of all preset positions in each grid unit at each moment according to the stress distribution factor and strain weight of each grid unit at each moment, specifically: calculating the normalized result of the product of the stress distribution factor of each grid unit and the corresponding strain weight, calculating the mean of the flatness of all preset positions in each grid unit, recorded as the second mean, calculating the multiplication result of the normalized result of each grid unit and the second mean, and the flatness of the aluminum foil semi-finished product at each moment in the finishing rolling process is the mean of the multiplication results of all grid units at each moment.

[0057] It should be noted that the normalization result is obtained by using the Sigmoid function in this embodiment, and the implementer can choose other existing feasible normalization methods at will, and this embodiment does not limit it.

[0058] S8, based on the error between the flatness of the aluminum foil semi-finished product at each moment in the finishing rolling process and the target flatness, a control algorithm is used to regulate the rolling force at each moment in the finishing rolling process.

[0059] In this embodiment, according to the error between the target flatness and the flatness of the aluminum foil semi-finished product at each moment, the PID (Proportional Integral Derivative) control algorithm is used to control the rolling force at each moment during the finishing rolling process. The control range of the rolling force is 30-45MPa. In this embodiment, the proportional coefficient of the PID control algorithm is set to 0.1, the integral coefficient is set to 0.3, and the differential coefficient is set to 0.05. The implementer can set it according to the actual situation. The PID control algorithm is an existing well-known technology, and the specific content is not repeated. In this embodiment, the target flatness is 2IU, where 1IU=10μm / m.

[0060] After the fine rolling, the aluminum foil material of Example 1 is obtained, and the thickness is 0.006 mm. Figure 2 shown.

[0061] Example 2 See also Figure 1, which shows a flow chart of the steps of a method for preparing a high-performance aluminum foil material provided in Example 2 of the present application, the method comprising the following steps: S1, putting the aluminum liquid into a refining furnace and refining it by mixing active gas and inert gas.

[0062] The raw materials for preparing the aluminum foil material in this embodiment include: Si: 0.10-0.13%, Fe: 0.40-0.45%, Cu: 0.01%, Mn: 0.01%, Mg: 0.005%, Zn: 0.03%, Ti: 0.01-0.03%, Al: 99.35%. All the raw materials are put into a smelting furnace according to their weight percentages for smelting to obtain aluminum liquid; the aluminum liquid may contain inevitable impurities.

[0063] Then the aluminum liquid is put into the refining furnace for refining. This embodiment uses a mixed refining method of active gas plus inert gas to achieve the best purification effect. The active gas is chlorine, and the amount of chlorine added is 8% of the aluminum melt. The aluminum chloride gas generated by the reaction between chlorine and the aluminum melt can effectively remove hydrogen and some fine inclusions. In addition to reacting with aluminum to generate aluminum chloride, chlorine also reacts with hydrogen in the melt to generate HCl. This reaction is rapid and degassing is fast. Therefore, chlorine refining has the effects of both physical degassing and chemical degassing, and the refining effect is relatively good. The inert gas is argon, and the flow rate of argon is controlled at 15L / min. Its inertness and good stirring effect are used to promote the floating removal of gas and inclusions in the aluminum liquid.

[0064] In the process of aluminum liquid refining, the solvent used is NaCl-KCl series flux. In this embodiment, the ratio of NaCl to KCl is 40:40, the amount of NaCl-KCl series flux added is 4% of the aluminum melt, the refining agent used is Al, the amount of refining agent added is 2kg / t, and the refining process lasts for 45 minutes. During this period, a strong agitator is required to ensure that the refining agent is evenly dispersed in the aluminum liquid to give full play to its purification effect.

[0065] S2, the refined aluminum liquid is cast-rolled by a casting and rolling mill; the aluminum plate obtained after the casting and rolling is cold-rolled, and the cold rolling includes a first cold rolling and a second cold rolling to obtain an aluminum foil semi-finished product; wherein, two annealings are performed after the first cold rolling.

[0066] The refined aluminum liquid flows into the front box of the casting and rolling mill. In this embodiment, the liquid level height of the front box of the casting and rolling mill is 600mm, and the liquid level height of the front box needs to be accurately controlled within the range of ±2mm. The roller diameter is 800mm, the casting and rolling zone length is 60mm, the casting and rolling temperature is 690℃, and the casting and rolling speed is 950mm / min.

[0067] The cooling intensity during the casting and rolling process is achieved by controlling the flow rate of cooling water inside the roll and the temperature difference between the inlet and outlet water. The cooling water flow rate is 130m³ / h, and the inlet and outlet water temperature difference is maintained at 13°C to ensure that the surface temperature of the roll is uniform and stable, so that the aluminum liquid solidifies and crystallizes at a suitable cooling rate to obtain good structure and performance.

[0068] The thickness of the aluminum plate obtained after aluminum liquid casting is 5mm.

[0069] Then, the cast aluminum plate is cold rolled using a single-stand rolling mill. The cold rolling is divided into two times, namely the first cold rolling and the second cold rolling. The distribution of the pass processing rate is a key link in the cold rolling process. The first pass processing rate is accurately set according to the slab thickness and alloy properties. During the first cold rolling, the first pass processing rate in this embodiment is 22%, and the subsequent pass processing rates gradually decrease. The decreasing range is determined according to the work hardening characteristics of the alloy and the final thickness requirements of the product. In this embodiment, each pass decreases by 2%, and the number of cold rolling passes is 8.

[0070] During the second cold rolling, the processing rate of the first pass is 21%, and the processing rate of the subsequent passes decreases gradually. In this embodiment, each pass decreases by 2%, and the number of cold rolling passes is 6.

[0071] The thickness of the aluminum plate obtained after the first cold rolling is 0.3 mm. The aluminum plate obtained after the first cold rolling is recorded as the first aluminum plate. The first aluminum plate is annealed twice. The temperature of the first annealing is 430°C and the time is 6.5 hours. After the first annealing, the grain diameter is less than or equal to 0.12 mm. The temperature of the second annealing is 400°C and the time is 6.5 hours. After the second annealing, the grain diameter is less than or equal to 0.09 mm.

[0072] The aluminum sheet after the second cold rolling is recorded as an aluminum foil semi-finished product, and the thickness of the aluminum foil semi-finished product is 0.020 mm.

[0073] The remaining steps are exactly the same as those of Example 1 of the present application, and the thickness of the aluminum foil material of Example 2 of the present application is finally obtained to be 0.0050 mm.

[0074] Example 3 See also Figure 1 , which shows a flow chart of the steps of a method for preparing a high-performance aluminum foil material provided in Example 3 of the present application, the method comprising the following steps: S1, putting the aluminum liquid into a refining furnace and refining it by mixing active gas and inert gas.

[0075] The raw materials for preparing the aluminum foil material in this embodiment include: Si: 0.10-0.13%, Fe: 0.40-0.45%, Cu: 0.01%, Mn: 0.01%, Mg: 0.005%, Zn: 0.03%, Ti: 0.01-0.03%, Al: 99.35%. All the raw materials are put into a smelting furnace according to their weight percentages for smelting to obtain aluminum liquid; the aluminum liquid may contain inevitable impurities.

[0076] Then the aluminum liquid is put into the refining furnace for refining. This embodiment uses a mixed refining method of active gas plus inert gas to achieve the best purification effect. The active gas is chlorine, and the amount of chlorine added is 10% of the aluminum melt. The aluminum chloride gas generated by its reaction with the aluminum melt can effectively remove hydrogen and some fine inclusions. In addition to reacting with aluminum to generate aluminum chloride, chlorine also reacts with hydrogen in the melt to generate HCl. This reaction is rapid and degassing is fast. Therefore, chlorine refining has the effects of both physical degassing and chemical degassing, and the refining effect is relatively good. The inert gas is argon, and the flow rate of argon is controlled at 20L / min. Its inertness and good stirring effect are used to promote the floating removal of gas and inclusions in the aluminum liquid.

[0077] In the process of aluminum liquid refining, the solvent used is NaCl-KCl series flux. In this embodiment, the ratio of NaCl to KCl is 60:40, the amount of NaCl-KCl series flux added is 5% of the aluminum melt, the refining agent used is Al, the amount of refining agent added is 2kg / t, and the refining process lasts for 60 minutes. During this period, a strong agitator is required to ensure that the refining agent is evenly dispersed in the aluminum liquid to give full play to its purification effect.

[0078] S2, the refined aluminum liquid is cast-rolled by a casting and rolling mill; the aluminum plate obtained after the casting and rolling is cold-rolled, and the cold rolling includes a first cold rolling and a second cold rolling to obtain an aluminum foil semi-finished product; wherein, two annealings are performed after the first cold rolling.

[0079] The refined aluminum liquid flows into the front box of the casting and rolling mill. In this embodiment, the liquid level height of the front box of the casting and rolling mill is 650mm, and the liquid level height of the front box needs to be accurately controlled within the range of ±2mm. The roller diameter is 800mm, the casting and rolling zone length is 65mm, the casting and rolling temperature is 695℃, and the casting and rolling speed is 1050mm / min.

[0080] The cooling intensity during the casting and rolling process is achieved by controlling the flow rate of cooling water inside the roll and the temperature difference between the inlet and outlet water. The cooling water flow rate is 150m³ / h, and the inlet and outlet water temperature difference is maintained at 15°C to ensure that the surface temperature of the roll is uniform and stable, so that the aluminum liquid solidifies and crystallizes at a suitable cooling rate to obtain good structure and performance.

[0081] The thickness of the aluminum plate obtained after aluminum liquid casting is 3mm.

[0082] Then, the cast aluminum plate is cold rolled using a single-stand rolling mill. The cold rolling is divided into two times, namely the first cold rolling and the second cold rolling. The distribution of the pass processing rate is a key link in the cold rolling process. The first pass processing rate is accurately set according to the slab thickness and alloy properties. During the first cold rolling, the first pass processing rate in this embodiment is 22%, and the subsequent pass processing rates gradually decrease. The decreasing range is determined according to the work hardening characteristics of the alloy and the final thickness requirements of the product. In this embodiment, each pass decreases by 2%, and the number of cold rolling passes is 8.

[0083] During the second cold rolling, the processing rate of the first pass is 21%, and the processing rate of the subsequent passes decreases gradually. In this embodiment, each pass decreases by 2%, and the number of cold rolling passes is 6.

[0084] The thickness of the aluminum plate obtained after the first cold rolling is 0.2 mm. The aluminum plate obtained after the first cold rolling is recorded as the first aluminum plate. The first aluminum plate is annealed twice. The temperature of the first annealing is 440°C and the time is 8 hours. After the first annealing, the grain diameter is less than or equal to 0.12 mm. The temperature of the second annealing is 420°C and the time is 8 hours. After the second annealing, the grain diameter is less than or equal to 0.09 mm.

[0085] The aluminum sheet after the second cold rolling is recorded as an aluminum foil semi-finished product, and the thickness of the aluminum foil semi-finished product is 0.012 mm.

[0086] The remaining steps are exactly the same as those of Example 1 of the present application, and the thickness of the aluminum foil material of Example 3 of the present application is finally obtained to be 0.0042 mm.

[0087] Comparative Example 1 In Example 1 of the present application, the rolling force is set to 40 MPa, and the rolling force during the finish rolling process is not adjusted. The rest of the steps and parameters are exactly the same as those in Example 1 of the present application to obtain the aluminum foil material prepared in Comparative Example 1.

[0088] Comparative Example 2 In Example 2 of the present application, the rolling force is set to 40 MPa, and the rolling force during the finish rolling process is not adjusted. The rest of the steps and parameters are exactly the same as those in Example 2 of the present application to obtain the aluminum foil material prepared in Comparative Example 2.

[0089] Comparative Example 3 In Example 3 of the present application, the rolling force is set to 40 MPa, and the rolling force during the finish rolling process is not adjusted. The rest of the steps and parameters are exactly the same as those in Example 3 of the present application to obtain the aluminum foil material prepared in Comparative Example 3.

[0090] The flatness of the aluminum foil materials of each embodiment and each comparative example of the present application was measured by a laser displacement sensor, and the specific results are shown in Table 1.

[0091] Table 1 Comparison results of flatness of the examples and comparative examples Examples and Comparative Examples Average flatness (IU) Example 1 1.8 Example 2 1.5 Example 3 1.2 Comparative Example 1 3.1 Comparative Example 2 2.6 Comparative Example 3 3.7 It can be seen from Table 1 that by adjusting the rolling force during the finish rolling process, an aluminum foil material with lower flatness is obtained, and the performance of the aluminum foil material is improved.

[0092] Based on the same inventive concept as the above method, an embodiment of the present application also provides a high-performance aluminum foil material, which is prepared by any one of the preparation methods described in the above-mentioned high-performance aluminum foil material preparation methods.

[0093] It should be noted that the above sequence of the embodiments of the present application is for description only and does not represent the advantages and disadvantages of the embodiments. The above is a description of a specific embodiment of this specification. In addition, the processes depicted in the accompanying drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0094] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0095] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the principles of the present application should be included in the protection scope of the present application.

Claims

1. A method for preparing a high-performance aluminum foil material, characterized in that: The method comprises the following steps: The raw materials include iron, silicon, titanium, copper, magnesium, manganese, zinc and aluminum. All the raw materials are placed in a smelting furnace according to a set weight percentage to prepare aluminum liquid, and the aluminum liquid is placed in a refining furnace for refining; The refined aluminum liquid is sequentially subjected to cast rolling and cold rolling, wherein the cold rolling includes a first cold rolling and a second cold rolling, to obtain a semi-finished aluminum foil; wherein, the first cold rolling is followed by two annealing steps; The aluminum foil semi-finished product is subjected to finish rolling. During the finish rolling process, the flatness of each preset position of the aluminum foil semi-finished product at each time is collected; the stress and rolling force of each position of the aluminum foil semi-finished product at each time are measured; The aluminum foil semi-finished product is evenly divided into grid units, and based on the distribution of stress at all positions in each grid unit at each time, all grid units at each time are divided into a plurality of stress regions; Analyze the change rate of stress at all positions in each grid unit at each moment, and combine the preset weight of each grid unit at each moment to obtain the stress distribution factor of each grid unit at each moment; The correlation between the stress and rolling force of all grid units belonging to each stress area at each moment is analyzed respectively, and the strain weights of all grid units belonging to each stress area at each moment are obtained. Combined with the stress distribution factor, the mean flatness of all preset positions in each grid unit at each moment is corrected to obtain the flatness of the aluminum foil semi-finished product at each moment during the finishing rolling process; Based on the error between the flatness and the target flatness, a control algorithm is used to regulate the rolling force at each moment during the finishing rolling process; After fine rolling, aluminum foil material is obtained.

2. A method for preparing a high-performance aluminum foil material according to claim 1, characterized in that: The weight percentages of the raw material components are: Si: 0.10~0.13%, Fe: 0.40~0.45%, Cu: 0.01%, Mn: 0.01%, Mg: 0.005%, Zn: 0.03%, Ti: 0.01~0.03%, Al: 99.35%.

3. The method for preparing a high-performance aluminum foil material according to claim 1, characterized in that: The refining adopts a mixed method of active gas and inert gas, the active gas is chlorine, and the addition amount is 5% to 10% of the aluminum melt, and the inert gas is argon, and the flow rate of argon is controlled at 10 to 20 L / min.

4. The method for preparing a high-performance aluminum foil material according to claim 1, characterized in that: The refining uses a mixed solvent of NaCl and KCl, wherein the ratio of NaCl to KCl is between 40:60 and 60:40, the amount of the mixed solvent added is 2% to 5% of the aluminum liquid, the refining time is 30 to 60 minutes, and the refining agent used is Al.

5. The method for preparing a high-performance aluminum foil material according to claim 1, characterized in that: The casting temperature is 685-695°C, the casting speed is 850-1050 mm / min, the length of the casting zone is 55-65 mm, the cooling water flow rate is 100-150 m³ / h, the inlet and outlet water temperature difference is 10-15°C, and the liquid level is 550-650 mm; The thickness of the aluminum plate after casting and rolling is 3-8 mm.

6. The method for preparing a high-performance aluminum foil material according to claim 1, characterized in that: The thickness of the aluminum plate after the first cold rolling is 0.2-0.4 mm, the thickness of the aluminum foil semi-finished product after the second cold rolling is 0.012-0.028 mm, the temperature of the first annealing in the two annealings is 420-440° C., the time is 5-8 hours, and the grain diameter after the first annealing is less than or equal to 0.12 mm, the temperature of the second annealing is 380-420° C., the time is 5-8 hours, and the grain diameter after the second annealing is less than or equal to 0.09 mm.

7. The method for preparing a high-performance aluminum foil material according to claim 1, characterized in that: The method of dividing all grid cells at each moment into a plurality of stress regions includes: Calculate the mean value and dispersion degree of the modulus value of stress at all positions of the aluminum foil semi-finished product at each moment, take the sum of the mean value of the modulus value and the dispersion degree as the first threshold, and take the difference between the mean value of the modulus value and the dispersion degree as the second threshold; The mean of the modulus values ​​of stress at all positions in each grid unit at each moment is calculated and recorded as the first mean value. The grid units whose first mean value is greater than the first threshold value are regarded as high stress areas, the grid units whose first mean value is less than the second threshold value are regarded as low stress areas, and the grid units other than the high stress areas and the low stress areas are regarded as medium stress areas.

8. A method for preparing a high-performance aluminum foil material as claimed in claim 7, characterized in that: The determination of the stress distribution factor includes: Based on the stress at all positions in each grid unit, the composite stress of each grid unit is obtained, and the gradient of the composite stress of each grid unit is calculated, wherein the stress distribution factor is a fusion result of the modulus of the gradient and the preset weight; Determination of the strain weights of all mesh cells belonging to the high stress zone includes: forming the modules of the rolling force of all mesh cells belonging to the high stress zone into a first sequence, forming the modules of the synthetic stress of all mesh cells belonging to the high stress zone into a second sequence, and the strain weight is the correlation between the first sequence and the second sequence.

9. The method for preparing a high-performance aluminum foil material according to claim 1, characterized in that: The determination of the flatness of the semi-finished aluminum foil product at each moment during the finishing rolling process includes: Calculate the normalized result of the product of the stress distribution factor of each grid unit and the corresponding strain weight, calculate the mean of the flatness of all preset positions in each grid unit, record it as the second mean, calculate the multiplication result of the normalized result of each grid unit and the second mean, and the flatness of the aluminum plate at each moment is the mean of the multiplication results of all grid units at each moment; The thickness of the aluminum foil material obtained after the finish rolling is 0.0042-0.006 mm.

10. A high performance aluminum foil material, characterized in that: The method is prepared by any one of claims 1 to 9.

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