Ultra-thin aluminum alloy for energy storage system and preparation process of ultra-thin aluminum alloy

Abstract

The invention relates to an ultra-thin aluminum alloy for an energy storage system and a preparation process of the ultra-thin aluminum alloy. The preparation process comprises the following steps of smelting and casting, hot rolling, cold rolling, heat treatment, surface treatment and shearing forming. By reasonably adding alloy elements such as magnesium, copper, silicon, zinc, manganese, titanium and scandium and strictly controlling smelting refining, casting cooling speed, rolling reduction and heat treatment temperature and time, the mechanical property and surface quality of the aluminum alloy are remarkably improved; a nitric acid and phosphoric acid mixed acid solution pickling and low-concentration passivation process is adopted for surface treatment, and the corrosion resistance and binding performance of the aluminum foil are further enhanced. The thickness of the prepared ultrathin aluminum alloy can be controlled between 50 microns and 200 microns, and the ultrathin aluminum alloy has the advantages of being uniform in thickness, smooth and clean in surface and stable in performance, and is particularly suitable for conductive and structural materials in an energy storage system. The process is green and efficient, the product quality is excellent, and the method is suitable for large-scale industrial production and has wide market application prospects.

Description

Technical Field

[0001] The present invention relates to the field of preparation of aluminum alloys, and more specifically to an ultra-thin aluminum alloy for an energy storage system and a preparation process thereof. Background Art

[0002] As an important part of the modern energy field, energy storage technology plays a key role in achieving efficient use of renewable energy, building smart grids, and improving power quality. Energy storage systems are integrated and modular energy management units, and their performance directly affects energy storage efficiency, service life, and safety. The development of material technology, especially structural materials, is of great significance to the lightweight, reliability, and energy density of energy storage systems.

[0003] The preparation of ultra-thin aluminum alloys for energy storage systems currently has the following difficulties:

[0004] (1) Uneven thickness: It is often difficult to ensure the uniformity of thickness of ultra-thin aluminum alloy plates during the rolling process, resulting in fluctuations in material properties.

[0005] (2) Poor surface quality: The surface of ultra-thin aluminum alloy is prone to scratches, indentations, oxide scale and other defects, which affect its subsequent processing performance and service life.

[0006] (3) Degradation of mechanical properties: During the ultra-thin process, the mechanical properties of aluminum alloys significantly decrease, affecting their stability and safety in energy storage systems. However, traditional aluminum alloy products on the market currently have difficulty in achieving a balance between strength, thermal conductivity, and ultra-thin processability. Ordinary aluminum alloys are prone to deformation, cracking, and other problems in an ultra-thin state, and their thermal conductivity and corrosion resistance are limited, making it difficult to meet the emerging needs of energy storage systems.

[0007] In view of the above problems, it is urgent to develop an ultra-thin aluminum alloy material suitable for energy storage systems and its preparation process. Summary of the invention

[0008] In order to solve the problems existing in the prior art, the present invention provides an ultra-thin aluminum alloy material suitable for an energy storage system and a preparation process thereof. The specific scheme is as follows:

[0009] A preparation process of an ultra-thin aluminum alloy for an energy storage system, the preparation process comprising the following steps:

[0010] S1. Melting and casting: Place the aluminum ingot in a melting furnace, heat it to 730℃-750℃, add magnesium, copper, silicon, zinc, manganese, titanium and scandium alloy elements in sequence, and ensure uniform stirring; Casting: Pour the melt into a semi-continuous casting mold, and control the cooling rate at 20℃ / s-50℃ / s;

[0011] S2, hot rolling: the initial rolling temperature is set at 400℃-450℃; the intermediate annealing parameters are kept at 300℃-350℃ for 1-2 hours;

[0012] S3, cold rolling: cooling the hot-rolled aluminum sheet to room temperature, and cold rolling it to 50μm-200μm through multiple passes; the reduction of each cold rolling pass is controlled at 10%-20%;

[0013] S4, heat treatment: including solution treatment and aging treatment;

[0014] S5. Surface treatment: pickling and passivation treatment of the aluminum foil surface;

[0015] S6. Cut the aluminum foil to the target thickness.

[0016] Furthermore, refining is performed during smelting in S1: nitrogen or argon is introduced for refining, the temperature is controlled at about 720°C, and the refining lasts for 10-15 minutes to remove hydrogen and inclusions in the melt.

[0017] Furthermore, during the hot rolling in S2, the reduction rate in each pass is 15-25%, and the total reduction rate is 90-95%.

[0018] Furthermore, during cold rolling, the initial roll gap is set to 90-95% of the thickness of the hot-rolled plate.

[0019] Furthermore, in the S4 heat treatment, the temperature of the solution treatment is 500-530°C, the holding time is 1-2h, and the temperature of the aging treatment is 120-160°C, and the holding time is 10-15h.

[0020] Furthermore, in S5, a mixed acid solution of nitric acid and phosphoric acid is used for pickling, the ratio of nitric acid to phosphoric acid is 1:2, and the pickling immersion time is 2 to 3 minutes.

[0021] Furthermore, the passivation step S5 is to immerse the aluminum foil in a chromic acid passivation solution for 1 to 2 minutes; the passivation temperature is 50 to 60° C., and the concentration of the passivation solution is 3 to 5%.

[0022] The aluminum alloy prepared according to the above preparation process has the following components: Mg 0.8-1.2%; Si 0.4-0.8%; Cu 0.2-0.4%; Zn 0.3-0.6%; Mn 0.1-0.3%; Ti 0.05-0.1%; Sc 0.05-0.1%; and the balance is Al.

[0023] Beneficial effects:

[0024] The present invention provides an ultra-thin aluminum alloy for energy storage system and its preparation process. By adding trace alloy elements of magnesium, copper, silicon, zinc, manganese, titanium and scandium, a fine and uniform organizational structure is formed, which effectively improves the mechanical properties and surface quality of the aluminum alloy. At the same time, through multiple cold rolling and precise heat treatment processes, ultra-thin aluminum foil with uniform thickness and smooth surface can be produced. The thickness can be controlled between 50μm and 200μm to meet the needs of different energy storage application scenarios.

[0025] The present invention adopts a mixed acid solution of nitric acid and phosphoric acid and a low-concentration passivation solution during the pickling and passivation process, thereby reducing the pollution to the environment in the traditional process; at the same time, the material waste is reduced through the efficient refining technology, which meets the requirements of green manufacturing. DETAILED DESCRIPTION

[0026] In order to deepen the understanding of the present invention, the present invention will be further described in detail below in conjunction with examples. The examples are only used to explain the present invention and do not constitute a limitation on the protection scope of the present invention.

[0027] Embodiment 1:

[0028] S1. Melting and Casting

[0029] Melting operation:

[0030] The aluminum ingot is placed in a melting furnace, heated to 740°C and begins to melt.

[0031] The following alloying elements are added in sequence:

[0032] Magnesium: added 1.0%,

[0033] Copper: Add 0.3%,

[0034] Silicon: Add 0.6%,

[0035] Zinc: added 0.4%,

[0036] Manganese: Add 0.2%,

[0037] Titanium: added 0.06%,

[0038] Scandium: added 0.08%.

[0039] Stirring ensures uniform dissolution of the alloying elements.

[0040] Refining treatment:

[0041] Refining is carried out by introducing argon gas with the temperature controlled at 720°C for 12 minutes to remove hydrogen and impurities in the melt.

[0042] Casting process:

[0043] The melt is poured into a semi-continuous casting mold and the cooling rate is controlled at 30°C / s to ensure uniform solidification of the aluminum alloy and grain refinement.

[0044] S2, hot rolling

[0045] Initial rolling temperature:

[0046] The ingot is heated to 430°C and sent to a hot rolling mill for initial rolling.

[0047] The reduction in each pass is 20%, and the initial thinning is to 3.0 mm.

[0048] Intermediate annealing:

[0049] Keep the temperature at 320℃ for 1.5 hours to eliminate internal stress and improve the plasticity of the material.

[0050] Continue hot rolling:

[0051] The hot rolling is continued to 1.0 mm according to similar operation, and the reduction in each pass is controlled at 20%, and the total reduction rate is about 90%.

[0052] S3, cold rolling

[0053] Cold rolling preparation:

[0054] The hot-rolled aluminum sheet is cooled to room temperature and cleaned to remove surface oxides.

[0055] The initial roll gap was set to 92% of the hot rolled plate thickness.

[0056] Cold rolling operation:

[0057] Through multiple cold rolling, the cold rolling is carried out to 120μm, and the reduction in each pass is controlled at 15%, with a total of 7 passes.

[0058] S4. Heat treatment

[0059] Solution treatment:

[0060] The aluminum alloy was heated to 520°C, kept at this temperature for 1.5 hours, and then immediately quenched.

[0061] Aging treatment:

[0062] The aging temperature is set at 140°C and kept at this temperature for 12 hours to enhance the strength and hardness of the aluminum alloy.

[0063] S5. Surface treatment

[0064] Pickling:

[0065] Use a mixed acid solution of nitric acid and phosphoric acid in a ratio of 1:2, soak for 2 minutes, and remove the surface oxide scale.

[0066] Passivation treatment:

[0067] The aluminum alloy was immersed in the chromic acid passivation solution for 1.5 minutes, the passivation temperature was set to 55°C, and the concentration was 4%.

[0068] S6. Cutting and Inspection

[0069] Cutting:

[0070] Aluminum foil is cut to target size using precision shearing equipment, with thickness accuracy controlled within ±0.01mm.

[0071] Quality Inspection:

[0072] The surface and thickness of the cut aluminum foil are inspected to ensure that it meets the application standards of the energy storage system.

[0073] Embodiment 2:

[0074] S1. Melting and Casting

[0075] Melting operation:

[0076] Put the aluminum ingot into the melting furnace, heat it to 745℃, and add alloy elements:

[0077] Magnesium: 0.9%,

[0078] Copper: 0.25%,

[0079] Silicon: 0.5%,

[0080] Zinc: 0.35%,

[0081] Manganese: 0.15%,

[0082] Titanium: 0.07%,

[0083] Scandium: 0.1%.

[0084] Refining and Degassing:

[0085] Argon gas was introduced into the melt and the melt was refined for 12 minutes to remove hydrogen and inclusions in the melt.

[0086] Casting process:

[0087] The melt was poured into a semi-continuous casting mold and the cooling rate was controlled at 40°C / s.

[0088] S2, hot rolling

[0089] Hot Rolled:

[0090] The ingot was heated to 420°C and hot rolling was started, with a reduction of 25% per pass until the ingot was rolled to 2.0 mm.

[0091] annealing:

[0092] Keep at 330℃ for 2 hours to relieve stress.

[0093] Continue hot rolling:

[0094] The aluminum alloy was rolled to 1.2 mm and rolled at a total reduction ratio of 92%.

[0095] S3, cold rolling

[0096] Cold rolling preparation:

[0097] The initial roll gap was set to 90% of the hot rolled plate thickness.

[0098] Cold rolling operation:

[0099] The steel was cold rolled to 100 μm in 8 passes, with the reduction in each pass controlled at 15%.

[0100] S4. Heat treatment

[0101] Solution treatment:

[0102] The aluminum alloy was heated to 510°C, kept at this temperature for 1 hour, and then quenched.

[0103] Aging treatment:

[0104] The aging temperature is 130℃ and the temperature is kept for 11 hours.

[0105] S5. Surface treatment

[0106] Pickling:

[0107] Use a 1:2 ratio of nitric acid to phosphoric acid solution and soak for 2.5 minutes.

[0108] Passivation:

[0109] The aluminum alloy foil was immersed in chromic acid passivation solution at a passivation temperature of 58°C for 1.2 minutes.

[0110] S6. Cutting and Inspection

[0111] Cutting:

[0112] Precision cut aluminum foil to target size.

[0113] test:

[0114] Test the surface flatness, thickness and strength of the aluminum foil to ensure it meets the requirements of the energy storage system.

[0115] Embodiment 3:

[0116] S1. Melting and Casting

[0117] Melting operation:

[0118] The aluminum ingot is melted to 735°C and the alloying elements are added in sequence:

[0119] Magnesium: 1.1%,

[0120] Copper: 0.35%,

[0121] Silicon: 0.7%,

[0122] Zinc: 0.5%,

[0123] Manganese: 0.25%,

[0124] Titanium: 0.05%,

[0125] Scandium: 0.09%.

[0126] Refining Operations:

[0127] Refining was performed by introducing argon gas, controlling the temperature at 720°C for 14 minutes. Casting process:

[0128] The melt was poured into a semi-continuous casting mold and the cooling rate was controlled at 25°C / s.

[0129] S2, hot rolling

[0130] Hot Rolled:

[0131] Heat the ingot to 440℃ and hot roll it to 2.5mm with a reduction of 22% per pass.

[0132] The annealing temperature is 310℃, and the temperature is kept for 1 hour to eliminate internal stress.

[0133] Continue hot rolling:

[0134] The total reduction rate was 90%, and rolling was continued to 0.8 mm.

[0135] S3, cold rolling

[0136] Cold rolling operation:

[0137] The initial roll gap was set to 91% of the hot rolled plate thickness.

[0138] Cold rolling was performed to 75 μm, with a reduction of 18% per pass, for a total of 6 passes.

[0139] S4. Heat treatment

[0140] Solution treatment:

[0141] The solution treatment temperature was 510°C for 1 hour and then quenched.

[0142] Aging treatment:

[0143] The aging temperature is 135℃ and kept warm for 10 hours.

[0144] S5. Surface treatment

[0145] Pickling:

[0146] The pickling solution ratio is 1:1 nitric acid and phosphoric acid, and the soaking time is 3 minutes.

[0147] Passivation:

[0148] Chromic acid is used in the passivation solution, and the passivation time is 1 minute.

[0149] S6. Cutting and Inspection

[0150] Cutting:

[0151] After cutting, the aluminum foil is inspected for size to ensure an accuracy of ±0.005mm.

[0152] Final inspection:

[0153] Strict surface inspection, thickness measurement and strength testing are carried out to ensure that the aluminum foil meets the application standards of energy storage systems.

[0154] As a further improvement, the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A process for preparing an ultra-thin aluminum alloy for an energy storage system, characterized in that: The preparation process comprises the following steps: S1. Melting and casting: Place the aluminum ingot in a melting furnace, heat it to 730℃-750℃, add magnesium, copper, silicon, zinc, manganese, titanium and scandium alloy elements in sequence, and ensure uniform stirring; Casting: Pour the melt into a semi-continuous casting mold, and control the cooling rate at 20℃ / s-50℃ / s; S2, hot rolling: the initial rolling temperature is set at 400℃-450℃; the intermediate annealing parameters are kept at 300℃-350℃ for 1-2 hours; S3, cold rolling: cooling the hot-rolled aluminum sheet to room temperature, and cold rolling it to 50μm-200μm through multiple passes; the reduction of each cold rolling pass is controlled at 10%-20%; S4, heat treatment: including solution treatment and aging treatment; S5. Surface treatment: pickling and passivation treatment of the aluminum foil surface; S6. Cut the aluminum foil to the target thickness.

2. The process for preparing an ultra-thin aluminum alloy for an energy storage system according to claim 1, characterized in that: Refining is performed during smelting in S1: nitrogen or argon is introduced for refining, the temperature is controlled at about 720°C, and the refining lasts for 10-15 minutes to remove hydrogen and inclusions in the melt.

3. The process for preparing an ultra-thin aluminum alloy for an energy storage system according to claim 1, characterized in that: During hot rolling in S2, the reduction in each pass is 15-25%, and the total reduction is 90-95%.

4. The process for preparing an ultra-thin aluminum alloy for an energy storage system according to claim 1, characterized in that: During cold rolling, the initial roll gap is set to 90-95% of the thickness of the hot rolled plate.

5. The process for preparing an ultra-thin aluminum alloy for an energy storage system according to claim 1, characterized in that: The temperature of the solution treatment in S4 heat treatment is 500-530°C; the holding time is 1-2h; the temperature of the aging treatment is 120-160°C, and the holding time is 10-15h.

6. The process for preparing an ultra-thin aluminum alloy for an energy storage system according to claim 1, characterized in that: In S5, a mixed acid solution of nitric acid and phosphoric acid is used for pickling, the ratio of nitric acid to phosphoric acid is 1:2, and the pickling immersion time is 2 to 3 minutes.

7. The process for preparing an ultra-thin aluminum alloy for an energy storage system according to claim 1, characterized in that: The passivation step of S5 is to immerse the aluminum foil in a chromic acid passivation solution for 1 to 2 minutes; the passivation temperature is 50 to 60° C., and the concentration of the passivation solution is 3 to 5%.

8. The aluminum alloy prepared by any one of the preparation processes of claims 1 to 7, characterized in that: The aluminum alloy components are as follows: Mg 0.8-1.2%, Si 0.4-0.8%, Cu 0.2-0.4%, Zn 0.3-0.6%, Mn 0.1-0.3%, Ti 0.05-0.1%, Sc 0.05-0.1% and the balance is Al.