Large-size high-temperature vacuum aluminum brazing foil and its processing method

Abstract

The application provides a large-size high-temperature vacuum aluminum filler metal foil and a processing method thereof. The processing method of the large-size high-temperature vacuum aluminum filler metal foil comprises the following steps: providing molten filler metal; the filler metal is an aluminum-silicon alloy; adding a modifier to the molten filler metal for refining; casting in a casting mold to obtain an ingot; performing multiple hot rolling treatments on the ingot, the reduction of each hot rolling treatment is less than 10%, and first annealing treatment is performed after each hot rolling treatment; performing multiple first cold rolling treatments, the reduction of each first cold rolling treatment is 10-15%, and second annealing treatment is performed after each first cold rolling treatment; performing multiple second cold rolling treatments, the reduction of each second cold rolling treatment is 4.5-5.5%, and at least two second annealing treatments are performed after each second cold rolling treatment; and performing multiple third cold rolling treatments to obtain the large-size high-temperature vacuum aluminum filler metal foil.

Description

Technical Field

[0001] This application relates to the field of materials preparation technology, and in particular to a large-size high-temperature vacuum aluminum brazing foil and its processing and forming method. Background Technology

[0002] The production process of brazing filler metals (including copper and copper alloys, copper-phosphorus alloys, silver alloys and aluminum alloys) is actually the production process of non-ferrous metal wires.

[0003] As vacuum brazing becomes more widespread and the size of welded products increases, the original 120mm wide foil material is no longer sufficient for welding requirements. Multiple 120mm foil materials can only be used by splicing them together. However, splicing and brazing can easily lead to incomplete welds at the splice points, which can cause quality problems for the products. Summary of the Invention

[0004] In view of this, the purpose of this application is to provide a large-size high-temperature vacuum aluminum brazing foil and its processing and forming method.

[0005] To achieve the above objectives, this application provides a method for processing and forming large-size high-temperature vacuum aluminum brazing foil, comprising:

[0006] Provide molten brazing filler metal; the brazing filler metal is an aluminum-silicon alloy;

[0007] A modifier is added to the molten solder for refining;

[0008] The casting is carried out in a casting mold to obtain an ingot;

[0009] The ingot is subjected to multiple hot rolling processes, with each hot rolling process having a rolling depth of less than 10%, and a first annealing process is performed after each hot rolling process.

[0010] Multiple first cold rolling processes are performed, with each first cold rolling process having a roll weight of 10-15%, and a second annealing process is performed after each first cold rolling process.

[0011] Multiple second cold rolling processes are performed, with a rolling reduction of 4.5-5.5% in each second cold rolling process, and at least two second annealing processes are performed after each second cold rolling process;

[0012] The large-size high-temperature vacuum aluminum brazing foil is obtained by performing multiple third cold rolling processes.

[0013] In some embodiments, the refining process of adding a modifier to the molten solder includes:

[0014] Add lanthanum modifier in batches at a mass fraction of 0.1-0.3% of the solder.

[0015] After the lanthanum modifier is melted, aluminum-strontium master alloy and aluminum-magnesium master alloy are added; the aluminum-strontium master alloy accounts for 0.05-0.1% of the solder mass.

[0016] Refining with inert gas.

[0017] In some embodiments, the casting model is a sand mold.

[0018] In some embodiments, casting is performed simultaneously using at least two pouring gates.

[0019] In some embodiments, the hot rolling temperature is 480-520°C, the first annealing temperature is 280-320°C, and the holding time is 30-90 minutes.

[0020] In some embodiments, after hot rolling, the thickness of the resulting brazing filler metal is 1 / 18 of the thickness of the ingot.

[0021] In some embodiments, after the first cold rolling process, the ratio of the thickness of the resulting brazing filler metal to the thickness of the ingot is 17 / 180; after the second cold rolling process, the ratio of the thickness of the resulting brazing filler metal to the thickness of the ingot is 1 / 180.

[0022] In some embodiments, the temperature of the second annealing treatment is 280-320°C, and the holding time is 18-22 minutes.

[0023] In some embodiments, the large-size high-temperature vacuum aluminum brazing foil has a width of 300 mm and a thickness of 0.05 mm.

[0024] This application also provides a large-size high-temperature vacuum aluminum brazing foil, which is prepared by the processing and forming method of large-size high-temperature vacuum aluminum brazing foil as described in any of the preceding claims.

[0025] As can be seen from the above, the processing and forming method for large-size high-temperature vacuum aluminum brazing foil provided in this application involves providing molten brazing filler metal, which is an aluminum-silicon alloy; adding a modifier to the molten brazing filler metal for refining; casting in a sand mold to obtain an ingot; subjecting the ingot to multiple hot rolling processes, with the thickness reduction of the ingot less than 10% after each hot rolling process, and performing a first annealing process after each hot rolling; performing multiple first cold rolling processes, with a rolling reduction of 10-15% in each first cold rolling process, and performing a second annealing process after each first cold rolling; performing multiple second cold rolling processes, with a rolling reduction of 4.5-5.5% in each second cold rolling process, and performing at least two second annealing processes after each second cold rolling; and performing multiple third cold rolling processes to obtain the large-size high-temperature vacuum aluminum brazing foil. This method can directly produce large-size high-temperature vacuum aluminum brazing foil with good tensile strength, avoiding the cumbersome operation of splicing small-size high-temperature vacuum aluminum brazing foil, and also avoiding safety hazards at the splicing points. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in this application or related technologies, the drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic flowchart illustrating the processing and forming method of large-size high-temperature vacuum aluminum brazing foil according to an embodiment of this application.

[0028] Figure 2 This is another schematic diagram of the processing and forming method of large-size high-temperature vacuum aluminum brazing foil according to an embodiment of this application;

[0029] Figure 3 This is a schematic diagram of the metallographic microstructure of the ingot prepared in Example 1 of this application;

[0030] Figure 4 The large-size high-temperature vacuum aluminum brazing foil prepared in Example 1 of this application. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.

[0032] It should be noted that, unless otherwise defined, the technical or scientific terms used in the embodiments of this application should have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," and similar terms used in the embodiments of this application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word covers the element or object listed following the word and its equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect.

[0033] In related technologies, brazing filler metal production mainly employs a process of melting and casting → extrusion → stretching (rolling). Among these, advanced brazing filler metal manufacturers have adopted horizontal continuous casting (φ<100mm) and vertical semi-continuous casting (φ>100mm). Several companies have also adopted gas-protected continuous casting technology, significantly improving product quality. The extrusion process is a key step affecting brazing filler metal production efficiency and even production costs. Currently, most brazing filler metal manufacturers use small-tonnage extruders, mostly 1000kN, resulting in low production efficiency. However, in recent years, some companies have adopted 600-12000kN extruders, equipped with PLC-controlled deceleration and isothermal extrusion operations, improving productivity and product quality. Some products also utilize nitrogen-protected extrusion, directly yielding finished products with a smooth surface. Traditional stretching processes mostly employ cold drawing followed by annealing. Currently, resistance heating stretching processes in China can significantly improve the production efficiency of small-diameter brazing filler metals.

[0034] However, for large-sized foils, such as those with a width of 300mm, the large size and thinness make fabrication difficult due to numerous factors influencing the formation of the texture. These factors include the amount of deformation, heating temperature, deformation rate, temperature at which deformation ends, ingot quality, stacking fault energy, impurity element content, and the content and distribution of the second phase. These factors can easily cause cracks or breaks during fabrication, making it challenging to produce. Therefore, there are currently no commercially available products that directly fabricate 300mm wide foils using solder. The common approach is to splice multiple 120mm foils together. However, this often results in weak solder joints at the splicing points, reducing the tensile strength of the foil and leading to significant quality risks in the product.

[0035] Based on this, the present application provides a large-size high-temperature vacuum aluminum brazing foil and its processing and forming method, which can solve the problem of insufficient tensile strength of current large-size foils to a certain extent.

[0036] like Figure 1 and Figure 2As shown in the embodiment of this application, a method for processing and forming large-size high-temperature vacuum aluminum brazing foil is provided, including:

[0037] S100 provides molten brazing filler metal; the brazing filler metal is an aluminum-silicon alloy.

[0038] S200, a modifier is added to the molten brazing filler metal for refining;

[0039] S300 is cast in a sand mold to obtain an ingot;

[0040] S400 involves multiple hot rolling processes on the ingot, with each hot rolling process having a roll weight of less than 10%, and a first annealing process performed after each hot rolling process.

[0041] S500 undergoes multiple first cold rolling processes, with each first cold rolling process involving a reduction of 10-15% in the rolling amount. A second annealing process is performed after each first cold rolling process.

[0042] S600 undergoes multiple second cold rolling processes, with each second cold rolling process having a roll weight of 4.5-5.5%, and each second cold rolling process is followed by at least two second annealing processes.

[0043] S700 undergoes multiple third cold rolling processes to obtain the large-size high-temperature vacuum aluminum brazing foil.

[0044] The processing and forming method for large-size high-temperature vacuum aluminum brazing foil provided in this application embodiment involves providing molten brazing filler metal, which is an aluminum-silicon alloy; refining the molten brazing filler metal by adding a modifier; casting in a sand mold to obtain an ingot; subjecting the ingot to multiple hot rolling processes, with the thickness reduction of the ingot less than 10% after each hot rolling process, and performing a first annealing treatment after each hot rolling process; performing multiple first cold rolling processes, with a rolling reduction of 10-15% in each first cold rolling process, and performing a second annealing treatment after each first cold rolling process; performing multiple second cold rolling processes, with a rolling reduction of 4.5-5.5% in each second cold rolling process, and performing at least two second annealing treatments after each second cold rolling process; and performing multiple third cold rolling processes to obtain the large-size high-temperature vacuum aluminum brazing foil. This method can directly produce large-size high-temperature vacuum aluminum brazing foil with good tensile strength, avoiding the cumbersome operation of splicing small-size high-temperature vacuum aluminum brazing foil, and also avoiding safety hazards at the splicing points.

[0045] In some embodiments, providing the molten solder in step S100 may specifically include:

[0046] Smelting aluminum-silicon master alloy and pure aluminum. A medium-frequency furnace or resistance furnace can be used for smelting. The specific amounts of aluminum-silicon master alloy and pure aluminum used can be determined based on the composition requirements of the large-size high-temperature vacuum aluminum brazing foil to be prepared.

[0047] After the aluminum-silicon master alloy and pure aluminum ingots have melted, maintain the furnace temperature at 700-750℃.

[0048] In some embodiments, in step S200, the modifier may include lanthanum and strontium, and the strontium modifier may account for 0.05-0.2% of the solder by mass, so that silicon can be well modified, changing from dendritic silicon to vermicular spheres, thereby significantly reducing the brittleness of the solder and providing a basis for the preparation of large-size high-temperature vacuum aluminum solder foil.

[0049] In some embodiments, refining the molten solder by adding a modifier may specifically include:

[0050] Lanthanum modifier, added in batches at a concentration of 0.1-0.3% by mass of the brazing filler metal, with the furnace temperature controlled at 700-750℃, can improve the modification effect of silicon, allowing for more complete modification of the aluminum-silicon master alloy and pure aluminum.

[0051] After the lanthanum modifier is melted, aluminum-strontium master alloy and aluminum-magnesium master alloy are added. The aluminum-strontium master alloy accounts for 0.05-0.1% of the solder mass to ensure good modification of silicon. The mass of the aluminum-magnesium master alloy can be determined according to the composition requirements of the large-size high-temperature vacuum aluminum solder foil to be prepared. Specifically, after the lanthanum modifier is melted, aluminum-strontium master alloy is added at a ratio of 0.05-0.1%, the temperature is maintained at 700℃, and after the aluminum-strontium master alloy melts, it is held at this temperature for 40 minutes, with the furnace temperature controlled at 700-750℃; after holding at this temperature for 40 minutes, aluminum-magnesium master alloy is added, with the furnace temperature controlled at 700℃.

[0052] Refining is performed using an inert gas, such as argon. The refining temperature can be 750℃, and the refining time can be 20-30 minutes.

[0053] In some embodiments, in step S300, the casting model is a sand mold. This avoids the problems associated with casting in iron molds, such as rapid cooling due to high thermal conductivity, which can lead to shrinkage cavities in the ingot.

[0054] Furthermore, casting is performed simultaneously using at least two pouring gates. That is, the sand mold has at least two pouring gates. For example, the sand mold has three pouring gates, which allows for rapid addition of casting liquid and avoids discontinuous solidification caused by pouring new casting liquid after the original casting liquid has solidified, thereby reducing the formation of porosity, etc.

[0055] In some embodiments, in step S400, during hot rolling, the width is greater than 900 mm to avoid uneven deformation, cracking, and deviation caused by a narrow width during hot rolling.

[0056] The hot rolling temperature is 480-520℃, and the first annealing temperature is 280-320℃, with a holding time of 18-22 minutes. Setting the temperature between 480-520℃ allows the alloy to achieve good thermoplasticity, reduces the metal's resistance to plastic deformation, ensures uniform temperature throughout the alloy, and refines silicon, thus significantly improving the brazing filler metal's plasticity. This allows the hot-rolled filler metal to undergo further rolling processes such as cold rolling. After hot rolling, the ratio of the filler metal's thickness to the ingot thickness is 1 / 18.

[0057] In some embodiments, in step S500, the initial rolling depth of the first cold rolling treatment is 10-15%, and a second annealing treatment is performed after each cold rolling. The annealing temperature is 300°C, and the holding time is 20 minutes, which can improve the rolling quality and reduce flash. This initial rolling depth followed by this temperature of annealing fully considers the impact of plastic deformation dominated by dislocation movement during rolling, accompanied by an increase in the density of internal metal defects and dynamic recrystallization dominated by recovery, grain nucleation, and growth, accompanied by a decrease in the density of internal crystal defects, on the microscopic deformation of the internal structure, thus improving the quality of deformation. After the first cold rolling treatment, the ratio of the thickness of the resulting brazing filler metal to the thickness of the ingot is 17 / 180.

[0058] In some embodiments, in step S600, the second cold rolling process differs from the first cold rolling process in that it involves changes in the rolling depth and the number of annealing cycles. Specifically, the rolling depth in the second cold rolling process is adjusted to 5%, and at least two second annealing processes are performed after cold rolling. This avoids cracks within the brazing filler metal sheet, resulting in a more stable internal microstructure that allows for subsequent third cold rolling. After the second cold rolling process, the thickness of the brazing filler metal can be 1 / 180th of the ingot thickness.

[0059] After the hot rolling, first cold rolling, and second cold rolling processes described above, the brittle phase structure of the brazing filler metal is refined and evenly distributed, improving the plasticity of the alloy, which can greatly reduce machining cracks and increase the final yield.

[0060] In some embodiments, in step S700, the third cold rolling process can be cold precision rolling, which does not require annealing, thus ultimately obtaining a large-size high-temperature vacuum aluminum brazing foil with a thickness of 1 / 1800 of the ingot thickness.

[0061] Based on the same inventive concept, this invention also provides a large-size high-temperature vacuum aluminum brazing foil, which is prepared by the processing method of large-size high-temperature vacuum aluminum brazing foil described in any one of the above technical solutions.

[0062] The technical solution of the present invention will be further described below with reference to specific embodiments.

[0063] Unless otherwise specified, the experimental methods described in the following examples are conventional methods.

[0064] Unless otherwise specified, all experimental materials used in the following examples were purchased from conventional biochemical reagent stores.

[0065] Example 1: Preparation of a high-temperature vacuum aluminum brazing foil with a width of 300 mm and a thickness of 0.05 mm.

[0066] Step 1: Wire rod melting:

[0067] Use a medium-frequency furnace or resistance furnace to melt 100 kg of the calculated aluminum-silicon master alloy and 50 kg of pure aluminum according to the brazing filler ratio. After the aluminum-silicon master alloy and pure aluminum ingots are melted, maintain the furnace temperature at 700℃.

[0068] Step 2: Silicon modification treatment:

[0069] Add the modifier slowly in batches at a ratio of 0.1% (0.15 kg) of lanthanum, maintaining the furnace temperature at 700℃. After the lanthanum modifier melts, add 0.075 kg of aluminum-strontium master alloy at a ratio of 0.05%, maintaining the temperature at 700℃. After the aluminum-strontium master alloy melts, hold the furnace at 700℃ for 40 minutes. After holding for 40 minutes, add the aluminum-magnesium master alloy calculated according to the brazing filler metal ratio and burn-off amount, maintaining the furnace temperature at 700℃. After the aluminum-magnesium master alloy is completely melted, refine the furnace charge using argon inert gas at a refining temperature of 750℃ for 20-30 minutes.

[0070] Step 3: Casting the ingot:

[0071] Casting after refining;

[0072] The ingot mold is made to be 1000mm in diameter, 90mm thick, and 900mm high. During casting, two gates (main and auxiliary) are used for simultaneous continuous casting, with an additional gating gate added.

[0073] Step 4: Hot rolling:

[0074] After homogenization treatment, the ingot is hot-rolled at an initial temperature of 500℃. The amount rolled in each pass is controlled to be less than 10%, and annealing is performed after each pass at 300℃. The holding time is controlled between 30-90 minutes, depending on the ingot thickness. After the final hot rolling pass, the brazing filler metal thickness is 5mm.

[0075] Step 5: First cold rolling:

[0076] The rolling allowance is 10-15%, and each roll is followed by an annealing treatment. The annealing temperature is 300℃, and the holding time is 20 minutes. After the first cold rolling in the final pass, the brazing filler metal thickness is 0.85 mm.

[0077] Step 6: Second cold rolling:

[0078] The rolling allowance is 5%, and the intermediate annealing is performed twice after each rolling pass. After the first cold rolling in the final pass, the brazing filler metal thickness is 0.5 mm.

[0079] Step 7: Cold finishing rolling on a four-roll mill:

[0080] The material undergoes precision rolling, with each roll being 10% of the total weight. The final high-temperature vacuum aluminum brazing foil, obtained through cold precision rolling, has a width of 300mm and a thickness of 0.05mm, with an appearance similar to... Figure 4 As shown.

[0081] Example 2

[0082] The only difference from Example 1 is that in the second step, the lanthanum modifier accounts for 0.3% (0.45 kg) of the solder mass fraction and the aluminum-strontium master alloy accounts for 0.1% (0.15 kg) of the solder mass fraction.

[0083] Example 3

[0084] The only difference from Example 1 is that, in the second step, the lanthanum modifier accounts for 0.2% (0.3 kg) of the solder mass fraction and the aluminum-strontium master alloy accounts for 0.075% (0.05 kg) of the solder mass fraction.

[0085] Comparative Example 1

[0086] The only difference from Example 1 is that the hot rolling temperature in the fourth step is 450°C.

[0087] Comparative Example 2

[0088] The only difference from Example 1 is that the hot rolling temperature in the fourth step is 550°C.

[0089] Comparative Example 3

[0090] The only difference from Example 1 is that the cold rolling temperature in steps 5 and 6 is 250°C.

[0091] Comparative Example 4

[0092] The only difference from Example 1 is that the cold rolling temperature in steps 5 and 6 is 350°C.

[0093] Comparative Example 5

[0094] The only difference from Example 1 is that in the second step, the aluminum-strontium master alloy accounts for 0.03% (0.045 kg) of the solder mass.

[0095] Comparative Example 6

[0096] The only difference from Example 1 is that in the second step, the aluminum-strontium master alloy accounts for 0.12% (0.18 kg) of the solder mass.

[0097] Test case

[0098] Performance tests were conducted on the large-size high-temperature vacuum aluminum brazing foils of Examples 1-3 and Comparative Examples 1-6. Metallographic microscopy was used to observe the surface for cracks and flash. Tensile strength was tested according to GB / T 2651-2008 (Tension Test Method for Welded Joints), and bending angle was tested according to GB / T 2653-2008 (Bending Test Method for Welded Joints). The test results are shown in Table 1. Additionally, the metallographic images of the ingots in Example 1 after the second step of the modification treatment were observed using metallographic microscopy. The results are as follows: Figure 3 As shown.

[0099] Table 1 Performance of Large-Size High-Temperature Vacuum Aluminum Brazing Foil

[0100]

[0101] As can be seen, the high-temperature vacuum aluminum brazing foils prepared in Examples 1 to 3 have good tensile strength and good bending angle, and can be used for welding, etc.

[0102] Comparing the various embodiments with Comparative Example 1, it can be seen that when the hot rolling temperature is lower than the set range of this application, the prepared high-temperature vacuum aluminum brazing foil exhibits burrs, poor surface quality, and a poor solder bending angle. Comparing the various embodiments with Comparative Example 2, it can be seen that when the hot rolling temperature is higher than the set range of this application, the prepared high-temperature vacuum aluminum brazing foil exhibits burrs, poor surface quality, low tensile strength, and a poor bending angle. Comparing the various embodiments with Comparative Example 3, when the cold rolling temperature is lower than the set range of this application, the prepared high-temperature vacuum aluminum brazing foil has poor surface quality and a small amount of burrs. Comparing the various embodiments with Comparative Example 4, it can be seen that when the cold rolling temperature is higher than the set range of this application, the prepared high-temperature vacuum aluminum brazing foil has poor surface quality, a small amount of burrs, and low tensile strength. Comparing the various embodiments with Comparative Example 5, when the strontium modifier is lower than the set range of this application, the prepared high-temperature vacuum aluminum brazing foil exhibits a small number of surface cracks, burrs during forming, low tensile strength, and a poor bending angle. Comparing the various embodiments with Comparative Example 6, it can be seen that when the strontium modifier is higher than the set range of this application, the surface of the prepared high-temperature vacuum aluminum brazing foil has a small number of cracks, flash appears during forming, and the tensile strength is low and the bending angle is poor.

[0103] Therefore, this application sets up a sand mold with three casting ports, uses an aluminum-strontium master alloy accounting for 0.05-0.1% of the brazing filler metal mass fraction for modification treatment, sets the hot rolling temperature to 480-520℃, and the cold rolling annealing temperature to 280-320℃. When the ratio of the thickness of the brazing filler metal obtained during cold rolling to the thickness of the ingot is 17 / 180, the rolling amount is changed, and the number of annealing times is increased. This improves the plasticity of the casting material and finally produces a large-size high-temperature vacuum aluminum brazing filler metal foil with good tensile strength, which can be used for brazing aluminum alloys, etc.

[0104] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of this disclosure (including the claims) is limited to these examples; within the framework of this disclosure, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of the embodiments of this disclosure as described above, which are not provided in detail for the sake of brevity.

[0105] Although this disclosure has been described in conjunction with specific embodiments thereof, many substitutions, modifications and variations of these embodiments will be apparent to those skilled in the art from the foregoing description.

[0106] This disclosure is intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.

Claims

1. A method for processing and forming large-size high-temperature vacuum aluminum brazing foil, characterized in that, include: Provide the molten solder; The brazing filler metal is an aluminum-silicon alloy; A modifier is added to the molten solder for refining; The casting is carried out in a casting mold to obtain an ingot; The ingot is subjected to multiple hot rolling processes, with each hot rolling process involving a reduction of less than 10%. A first annealing process is performed after each hot rolling process. The hot rolling temperature is 480-520℃, the first annealing temperature is 280-320℃, and the holding time is 30-90 minutes. After hot rolling, the ratio of the thickness of the obtained brazing filler metal to the thickness of the ingot is 1 / 18. Multiple first cold rolling processes are performed, with each first cold rolling process having a roll weight of 10-15%, and a second annealing process is performed after each first cold rolling process. Multiple second cold rolling processes are performed, with a rolling depth of 4.5-5.5% for each second cold rolling process, and at least two second annealing processes are performed after each second cold rolling process; after the second cold rolling process, the ratio of the thickness of the obtained brazing filler metal to the thickness of the ingot is 1 / 180. The large-size high-temperature vacuum aluminum brazing foil is obtained by performing multiple third-stage cold rolling processes; the large-size high-temperature vacuum aluminum brazing foil has a width of 300 mm and a thickness of 0.05 mm. The refining process of adding a modifier to the molten solder includes: Add lanthanum modifier in batches at a mass fraction of 0.1-0.3% of the solder. After the lanthanum modifier is melted, aluminum-strontium master alloy and aluminum-magnesium master alloy are added; the aluminum-strontium master alloy accounts for 0.05-0.1% of the solder mass. Refining with inert gas; The casting model is a sand mold, and casting is carried out simultaneously using at least two pouring ports.

2. The processing and forming method for large-size high-temperature vacuum aluminum brazing foil according to claim 1, characterized in that, The second annealing treatment is performed at a temperature of 280-320℃ for 18-22 minutes.

3. A large-size high-temperature vacuum aluminum brazing foil, characterized in that, It is prepared by the processing and forming method of large-size high-temperature vacuum aluminum brazing foil as described in any one of claims 1 to 2.

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