Processing method for preparing 1235 aluminum alloy new energy battery foil blank

Abstract

The invention discloses a processing method for preparing a 1235 aluminum alloy new energy battery foil blank, which specifically comprises the following steps: alloy raw material selection and proportioning: alloy components comprise 0.10%-0.25% of Si, 0.60%-0.80% of Fe, 0.01%-0.05% of Mn, 0.01%-0.03% of Cu and the balance of Al; the pure aluminum ingot is heated to 730-750 DEG C to be melted, alloy elements are gradually added, stirring is kept, and a refining agent is added for refining treatment; the filtered melt is subjected to a semi-continuous cast rolling process; and after cold rolling is conducted to the final thickness of 0.5-1.2 mm, online annealing is conducted, the annealing temperature ranges from 300 DEG C to 350 DEG C, and the time ranges from 2 hours to 4 hours. By means of the method, the 1235 aluminum alloy blank has the excellent mechanical performance that the tensile strength is larger than or equal to 120 MPa, the yield strength is larger than or equal to 50 MPa, the ductility is larger than or equal to 20%, corrosion resistance and size precision are achieved, and the requirements for light weight and high performance of new energy battery foil bodies can be met.

Description

Technical Field

[0001] The present invention relates to the field of preparation of battery foil blanks, and more specifically to a processing method for preparing 1235 aluminum alloy new energy battery foil blanks. Background Art

[0002] With the rapid development of the global new energy industry, especially the rise of the new energy automobile industry, the demand for lightweight materials has increased significantly. Lightweighting can not only effectively reduce the weight of the vehicle itself and improve energy efficiency, but also reduce carbon emissions, in line with current environmental protection policies and market trends. In this context, aluminum alloy materials have become one of the important candidate materials for new energy battery foils due to their excellent lightweight properties, high strength, good corrosion resistance and excellent forming performance.

[0003] 1235 aluminum alloy is an industrial pure aluminum alloy. It is widely used in cable sheaths, packaging materials and other fields due to its high conductivity, excellent ductility and low cost. However, in the manufacturing process of new energy battery foil, due to its special functional requirements, such as good impact resistance, high strength and high toughness, the traditional 1235 aluminum alloy production process can no longer meet the above requirements. This is because the microstructure in the traditional process cannot be effectively optimized, and the strength and toughness of the material are often difficult to balance, resulting in limitations in its application in new energy battery foil. Summary of the invention

[0004] In order to solve the shortcomings of the prior art, a processing method for preparing 1235 aluminum alloy new energy battery foil blank is provided. The specific scheme is as follows:

[0005] A processing method for preparing 1235 aluminum alloy new energy battery foil blank, the processing method comprising the following steps:

[0006] S1: Add alloy Si according to the following alloy mass percentages: 0.10% to 0.25%, Fe: 0.60% to 0.80%, Mn: 0.01% to 0.05%, Cu: 0.01% to 0.03%, and the rest is Al;

[0007] S2: Alloy smelting During the smelting process, the pure aluminum ingot is first placed in a smelting furnace and heated to 730℃~750℃ to completely melt it; Fe, Si, Mn and Cu elements are gradually added, and the addition speed is controlled to ensure uniform alloy composition;

[0008] S3: using a semi-continuous casting and rolling machine, the casting speed of the casting and rolling machine is 50-80 mm / min, and the final thickness of the cast and rolled billet is controlled at 6-8 mm; after the casting and rolling is completed, water cooling is used for rapid cooling, the cooling temperature is controlled at 20°C-25°C, and the cooling time is 30-50 seconds;

[0009] S4: placing the blank in a high-temperature soaking furnace, with a heating rate of 20-30°C / min; the soaking temperature of the blank is 480-500°C; the holding time is 12-24 hours; after the soaking is completed, the blank is cooled to 300-350°C by furnace cooling, and then air-cooled to room temperature;

[0010] S5. Hot rolling processing adopts reversible hot rolling mill;

[0011] S6. Cold rolling: rolling the billet to a final thickness of 0.5-1.2 mm according to demand; rolling speed: 100-200 m / min; after rolling, online annealing treatment is carried out, the annealing temperature is controlled at 300°C-350°C, and the time is 2-4 hours.

[0012] Furthermore, during the alloy smelting process, hexachloroethane is added as a refining agent, the amount of the refining agent is 0.3% to 0.5% of the total mass of the melt, the furnace temperature is maintained at 710° C. to 730° C., and the refining time is 15 to 20 minutes.

[0013] Furthermore, the casting and rolling process parameters are: casting and rolling inlet temperature: 680°C to 700°C; casting and rolling outlet temperature: 250°C to 300°C; casting and rolling pressure: 2.0 to 3.5 MPa.

[0014] Furthermore, the hot rolling process parameters are as follows: hot rolling inlet temperature: 400°C to 450°C; hot rolling outlet temperature: 200°C to 250°C; hot rolling thickness: the billet thickness is controlled at 1.5 to 3 mm.

[0015] Furthermore, in the hot rolling process, after each rolling pass, the billet needs to be reheated to 350°C to 400°C.

[0016] Furthermore, in the cold rolling and finished product processing steps, the annealing time is preferably 3 hours and the annealing temperature is preferably 320°C.

[0017] Furthermore, S2 is stirred during the addition process, each stirring lasts for 5 to 10 minutes, and the rotation speed is controlled at 100 to 150 rpm; after the melt is removed from the furnace and filtered through a ceramic tube, the temperature is reduced to 680 to 700°C at a rate of 5 to 10°C / min to keep the temperature stable.

[0018] Beneficial effects:

[0019] The present invention provides a processing method for preparing a 1235 aluminum alloy new energy battery foil blank. By optimizing the alloy composition design, smelting process, casting and rolling process, heat treatment process and subsequent rolling and surface treatment process, the 1235 aluminum alloy blank has the following beneficial effects:

[0020] (1) By optimizing the content ratio of iron and silicon and adding a small amount of manganese and copper, the tensile strength and yield strength of the material are effectively improved while maintaining a good elongation. Ultimately, the prepared 1235 aluminum alloy billet has excellent properties of tensile strength ≥120MPa, yield strength ≥50MPa, and elongation ≥20%.

[0021] (2) While ensuring the improvement of mechanical properties, the alloy composition is precisely controlled and efficient refining treatment is adopted, which effectively reduces the impurity content inside and on the surface of the material and greatly improves the corrosion resistance. After the neutral salt spray test, the blank had no obvious corrosion points within 48 hours, which fully meets the use requirements of new energy battery foil.

[0022] (3) By optimizing the casting and hot rolling process parameters and using homogenization heat treatment to eliminate internal stress, the microstructure of the billet is made more uniform, defects are greatly reduced, and the dimensional accuracy and flatness are significantly improved. DETAILED DESCRIPTION

[0023] 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.

[0024] Example 1

[0025] A processing method for preparing 1235 aluminum alloy new energy battery foil blank specifically comprises the following steps:

[0026] Step 1: Alloy raw material selection and ratio

[0027] Pure aluminum ingot (Al, content ≥99.35%), high-purity silicon (Si), iron (Fe), manganese (Mn) and copper (Cu) are selected as raw materials. The mass percentage of the alloy components is:

[0028] Si: 0.15%;

[0029] Fe: 0.70%;

[0030] Mn: 0.03%;

[0031] Cu: 0.02%;

[0032] The rest is aluminum.

[0033] Step 2: Alloy Melting

[0034] Place the pure aluminum ingot in a closed melting furnace and heat it to 740°C under argon protection to make it completely melted;

[0035] Fe, Si, Mn and Cu elements were slowly added in sequence, and the adding speed was controlled while the melt was kept uniformly stirred at a stirring speed of 120 rpm and each stirring lasted for 8 minutes;

[0036] After smelting, hexachloroethane was added to the melt as a refining agent in an amount of 0.4% of the total mass of the melt, and the furnace temperature was maintained at 720° C. The refining treatment was performed for 15 minutes to remove impurities and gases;

[0037] After refining, the melt was filtered through a ceramic tube, and the melt temperature was reduced to 690°C at a cooling rate of 5°C / min and kept stable.

[0038] Step 3: Casting and rolling

[0039] injecting the filtered melt into a semi-continuous casting and rolling mill;

[0040] The casting and rolling process parameters are:

[0041] Casting and rolling inlet temperature: 690℃;

[0042] Casting and rolling outlet temperature: 280℃;

[0043] Casting pressure: 2.5MPa;

[0044] Casting speed: 70mm / min;

[0045] The thickness of the billet after casting and rolling is controlled at 7mm;

[0046] After casting and rolling, water cooling is used for cooling, the cooling temperature is controlled at 22°C, and the cooling time is 40 seconds;

[0047] The cooled billet is sheared into fixed size, and the dimensional deviation is controlled within ±1.5%.

[0048] Step 4: Homogenization heat treatment

[0049] The cast and rolled billet is placed in a high-temperature soaking furnace and heated to a soaking temperature of 490°C at a heating rate of 25°C / min;

[0050] Keep at 490℃ for 12 hours;

[0051] After the uniform heating is completed, the blank is cooled to 320°C by furnace cooling and then air cooled to room temperature.

[0052] Step 5: Hot rolling

[0053] Hot rolling is carried out using a reversing hot rolling mill;

[0054] Hot rolling process parameters are:

[0055] Hot rolling inlet temperature: 420℃;

[0056] Hot rolling outlet temperature: 220℃;

[0057] The thickness of the blank is controlled at 2.5 mm;

[0058] After each rolling, the billet needs to be reheated to 380°C to eliminate the rolling hardening effect.

[0059] Step 6: Cold rolling and finished product processing

[0060] In the cold rolling process, the hot rolled billet is rolled to a final thickness of 0.8 mm;

[0061] The cold rolling speed is controlled at 150m / min;

[0062] After cold rolling, online annealing treatment is carried out, the annealing temperature is controlled at 320℃, and the annealing time is 3 hours;

[0063] Finally, the annealed billet is surface treated to clean the surface oxides and oil stains to improve corrosion resistance.

[0064] Performance Testing

[0065] After performance testing, the performance indicators of the finished product are as follows:

[0066] Tensile strength: 125MPa;

[0067] Yield strength: 55MPa;

[0068] Elongation: 22%;

[0069] There are no obvious corrosion spots after 48 hours of neutral salt spray test.

[0070] Example 2

[0071] A processing method for preparing 1235 aluminum alloy new energy battery foil blank, the specific steps are as follows:

[0072] Step 1: Alloy raw material selection and ratio

[0073] The mass percentage of alloy components is:

[0074] Si: 0.20%;

[0075] Fe: 0.75%;

[0076] Mn: 0.02%;

[0077] Cu: 0.03%;

[0078] The rest is aluminum.

[0079] Step 2: Alloy Melting

[0080] The pure aluminum ingot is placed in a closed melting furnace and heated to 745°C under argon protection;

[0081] Fe, Si, Mn, and Cu elements were slowly added in batches, with a stirring speed of 100 rpm and each stirring lasting 10 minutes;

[0082] After smelting, hexachloroethane was added as a refining agent in an amount of 0.5% of the total mass of the melt, the furnace temperature was maintained at 725°C, and the refining was carried out for 20 minutes;

[0083] The melt was filtered through a ceramic tube and the melt temperature was reduced to 700 °C at a cooling rate of 10 °C / min.

[0084] Step 3: Casting and rolling

[0085] The casting and rolling inlet temperature is 700℃, the outlet temperature is 270℃, and the casting and rolling pressure is 3.0MPa;

[0086] The casting speed is 60 mm / min, and the final casting billet thickness is 6.5 mm;

[0087] After the casting and rolling is completed, water is cooled to 25°C for 30 seconds.

[0088] Step 4: Homogenization heat treatment

[0089] The soaking temperature is controlled at 500°C, the holding time is 24 hours, the furnace is cooled to 350°C and then air-cooled.

[0090] Step 5: Hot rolling

[0091] The hot rolling thickness is controlled at 1.8 mm, and the hot rolling temperature ranges from 400°C to 250°C.

[0092] Step 6: Cold rolling and finished product processing

[0093] Cold rolled to a thickness of 0.6 mm, the annealing temperature was controlled at 300°C, and the annealing time was 4 hours.

[0094] Example 3

[0095] A processing method for preparing 1235 aluminum alloy new energy battery foil blank, the specific steps are as follows:

[0096] Step 1: Alloy raw material selection and ratio

[0097] The mass percentage of alloy components is:

[0098] Si: 0.12%;

[0099] Fe: 0.65%;

[0100] Mn: 0.01%;

[0101] Cu: 0.02%;

[0102] The rest is aluminum.

[0103] Step 2: Alloy Melting

[0104] The melting temperature was controlled at 730°C, the stirring speed was 150 rpm, and each stirring lasted for 5 minutes;

[0105] The amount of refining agent used was 0.3% of the melt mass, the refining time was 15 minutes, and after filtration, the temperature was lowered to 680°C at 5°C / min.

[0106] Step 3: Casting and rolling

[0107] The casting and rolling inlet temperature is 680℃, the outlet temperature is 260℃, and the casting and rolling pressure is 2.2MPa;

[0108] The casting speed is 80 mm / min, the casting thickness is 8 mm, and the water cooling time is 50 seconds.

[0109] Step 4: Homogenization heat treatment

[0110] The uniform heating temperature is 480℃, which is kept for 12 hours. The furnace is cooled to 300℃ and then air-cooled.

[0111] Step 5: Hot rolling

[0112] The hot rolling thickness is controlled at 2 mm and the steel is reheated to 350 °C after each pass.

[0113] Step 6: Cold rolling and finished product processing

[0114] Cold rolling to a final thickness of 1.2 mm, annealing temperature of 320 ° C, annealing time of 3 hours.

[0115] 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 processing method for preparing 1235 aluminum alloy new energy battery foil blank, characterized in that: The processing method comprises the following steps: S1: Add alloy Si according to the following alloy mass percentages: 0.10% to 0.25%, Fe: 0.60% to 0.80%, Mn: 0.01% to 0.05%, Cu: 0.01% to 0.03%, and the rest is Al; S2: Alloy smelting During the smelting process, the pure aluminum ingot is first placed in a smelting furnace and heated to 730℃~750℃ to completely melt it; Fe, Si, Mn and Cu elements are gradually added, and the addition speed is controlled to ensure uniform alloy composition; S3: using a semi-continuous casting and rolling machine, the casting speed of the casting and rolling machine is 50-80 mm / min, and the final thickness of the cast and rolled billet is controlled at 6-8 mm; after the casting and rolling is completed, water cooling is used for rapid cooling, the cooling temperature is controlled at 20°C-25°C, and the cooling time is 30-50 seconds; S4: placing the blank in a high-temperature soaking furnace, with a heating rate of 20-30°C / min; the soaking temperature of the blank is 480-500°C; the holding time is 12-24 hours; after the soaking is completed, the blank is cooled to 300-350°C by furnace cooling, and then air-cooled to room temperature; S5. Hot rolling processing adopts reversible hot rolling mill; S6. Cold rolling: rolling the billet to a final thickness of 0.5-1.2 mm according to demand; rolling speed: 100-200 m / min; after rolling, online annealing treatment is carried out, the annealing temperature is controlled at 300°C-350°C, and the time is 2-4 hours.

2. A processing method for preparing 1235 aluminum alloy new energy battery foil blank according to claim 1, characterized in that: During the alloy smelting process, hexachloroethane is added as a refining agent, the amount of which is 0.3% to 0.5% of the total mass of the melt, the furnace temperature is maintained at 710° C. to 730° C., and the refining time is 15 to 20 minutes.

3. A processing method for preparing 1235 aluminum alloy new energy battery foil blank according to claim 1, characterized in that: The casting and rolling process parameters are as follows: casting and rolling inlet temperature: 680°C ~ 700°C; casting and rolling outlet temperature: 250°C ~ 300°C; casting and rolling pressure: 2.0 ~ 3.5MPa.

4. A processing method for preparing 1235 aluminum alloy new energy battery foil blank according to claim 1, characterized in that: The hot rolling process parameters are as follows: hot rolling inlet temperature: 400°C ~ 450°C; hot rolling outlet temperature: 200°C ~ 250°C; hot rolling thickness: the billet thickness is controlled at 1.5 ~ 3 mm.

5. A processing method for preparing 1235 aluminum alloy new energy battery foil blank according to claim 1, characterized in that: In the hot rolling process, after each rolling pass, the billet needs to be reheated to 350℃~400℃.

6. A processing method for preparing 1235 aluminum alloy new energy battery foil blank according to claim 1, characterized in that: In the cold rolling and finishing process, the annealing time is 3 hours and the annealing temperature is 320°C.

7. A processing method for preparing 1235 aluminum alloy new energy battery foil blank according to claim 1, characterized in that: S2 is stirred during the addition process, and each stirring lasts for 5 to 10 minutes, and the rotation speed is controlled at 100 to 150 rpm; after the melt is removed from the furnace and filtered through a ceramic tube, it is cooled to 680 to 700°C at a rate of 5 to 10°C / min to keep the temperature stable.