Preparation method of ultrahigh-recombination-rate multi-layer aluminum alloy composite plate for brazing

Abstract

The invention relates to a preparation method of an ultrahigh-recombination-rate multi-layer aluminum alloy composite board for brazing, the aluminum alloy composite board comprises a core material and a composite cladding at least located on one side of the core material, the composite cladding is composed of an intermediate material and a brazing material, one side of the intermediate material is in contact with the core material, the other side of the intermediate material is in contact with the brazing material, the recombination rate of the brazing material is 5-15%, and the composite cladding is at least located on one side of the core material. The compounding rate of the intermediate material is greater than or equal to 22%, and the thickness ratio of the single-side composite cladding to the core material is within 2: 1; during preparation, the core material, the intermediate material and the brazing material are prepared firstly, then a core material cast ingot and a composite cladding cast ingot are stacked into a stacked material for hot rolling, then the stacked material is preheated to the target hot rolling temperature, and then the hot rolling bonding procedure, the hot rolling thinning pass and aftertreatment are sequentially carried out. According to the method, low-rejection-rate and stable mass production of the ultrahigh-recombination-rate aluminum alloy composite plate for brazing can be achieved, and the prepared ultrahigh-recombination-rate aluminum alloy composite plate for brazing has the effects of high strength, long service life and light weight.

Description

Technical Field

[0001] The invention belongs to the technical field of aluminum alloy composite plates for brazing, and relates to a method for preparing an ultra-high composite rate multi-layer aluminum alloy composite plate for brazing. Background Art

[0002] Conventional brazing aluminum alloy composite plates are usually composed of a composite structure with a brazing layer coated on the surface of the core layer. The ratio of the thickness of the single-side cladding layer to the thickness of the core layer usually needs to be less than 1:4. Such composite aluminum alloy products can be completed using conventional processes such as melting-sawing-soaking-milling-compounding-heating-hot rolling-cold rolling-annealing-slitting. However, when the ratio of the thickness of the single-side cladding layer to the thickness of the core layer is higher than 1:4, for composite plates of the same composite structure, it is usually necessary to match high-strength core materials to compensate for the performance degradation caused by the reduction in the proportion of core materials. However, it is difficult to achieve composite processing of such high-compound aluminum alloy materials with existing conventional processes.

[0003] With the development trend of lightweight and long life of global vehicles, the research direction of aluminum alloy composite plates has turned to the composite of multi-layer functional layers and core layers, specifically, the surface of the core layer is coated with a corrosion-resistant intermediate layer and a brazing layer in sequence. The higher the composite rate of the intermediate layer, the better the corrosion resistance of the material and the longer the life. However, too high a composite rate will lead to a reduction in the thickness of the core layer that provides the main strength contribution. When the total thickness is required to remain unchanged or further thinned, the composite material loses performance because the composite rate of the cladding (the general term for other layers other than the core layer) is too high, and the thickness of the core material that bears the main contribution to the mechanical properties is too small. In this case, it is usually necessary to select an ultra-high strength core material to ensure that the material performance meets the basic requirements. When ultra-high strength materials are used as core materials, it is possible to achieve product thinning while ensuring that the material strength meets the requirements. However, the strength and plasticity (or ductility) of aluminum alloys are a trade-off between performance. Generally, the higher the strength, the stronger the material rigidity and the worse the plasticity. When high-strength aluminum is selected as the core material and supplemented with ultra-high composite rate aluminum alloy composite plate processing becomes a major problem that needs to be solved urgently.

[0004] Therefore, it is of great significance to study a method for preparing a multi-layer aluminum alloy composite plate with ultra-high composite rate for brazing in order to solve the problems existing in the prior art. Summary of the invention

[0005] The purpose of the present invention is to solve the problems existing in the prior art and provide a method for preparing a super-high composite rate multi-layer aluminum alloy composite plate for brazing.

[0006] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0007] A method for preparing an ultra-high composite rate multi-layer aluminum alloy composite plate for brazing, wherein the aluminum alloy composite plate comprises a core material and a composite cladding at least located on one side of the core material, wherein the composite cladding is composed of an intermediate material and a brazing material, wherein one side of the intermediate material is in contact with the core material, and the other side is in contact with the brazing material; the composite rate of the brazing material (referring to the percentage of the brazing material thickness in the total thickness of the aluminum alloy composite plate) is 5-15%, the composite rate of the intermediate material (referring to the percentage of the intermediate material thickness in the total thickness of the aluminum alloy composite plate) is ≥22%, and the ratio of the thickness of the single-sided composite cladding to the core material is within 2:1; the preparation of the aluminum alloy composite plate comprises the following steps:

[0008] (1) Preparation of rolling objects;

[0009] The core material is an aluminum alloy with a tensile strength of 120-300 MPa and an elongation of 5-25%. Generally, the higher the strength, the worse the elongation. Exemplary core materials are medium- and high-strength alloys such as 3-series, 5-series, and 6-series improved alloys.

[0010] The difference in elongation after fracture between the intermediate material and the core material is 9-28%, for example, 9%, 10%, 11%, 17%, 23%, 28%, etc.; the difference in elongation after fracture between the intermediate material and the brazing material is ≤5%, for example, 0, 0.5%, 1%, 3%, 3.5%, 5%, etc.; the difference refers to the absolute value after subtracting the elongation values ​​of the two types of materials;

[0011] The intermediate material can be a 7-series Al-Zn alloy or a 3-series aluminum alloy modified with Zn. Its function is to improve the corrosion resistance of the material. By adding Zn to the intermediate layer, the material's own potential is reduced, the potential difference with the core material is increased, an electrochemical corrosion mechanism is formed, pitting corrosion is changed to surface corrosion, and the service life is increased.

[0012] The brazing material can be a 4-series Al-Si alloy or a 4-series modified Al-Si alloy, which can melt and wet the surface of the objects to be brazed to form an interface during brazing. When preparing an ultra-high composite rate multi-layer aluminum alloy composite plate with composite brazing materials on both sides, the brazing materials on both sides can be the same or different Al-Si alloys, and the composite rates can be the same or different;

[0013] After research, the inventors believe that the root cause of the rolling problem of such ultra-high composite aluminum alloy composite plates is that the high-strength core material has a large gap in processing plasticity with the composite skin material or intermediate material, which leads to large differences in deformation of each layer of alloy during hot rolling, and then serious problems of warping or buckling, making it impossible to achieve normal and smooth hot rolling production. In particular, when the composite rate is further increased, the multi-layer bonding problem caused by the plasticity difference is further amplified. This makes it difficult to industrialize the preparation of multi-layer aluminum alloy composite plates with ultra-high composite rates of more than 20%.

[0014] (2) Preheating;

[0015] stacking the core material ingot and the composite cladding ingot into a laminated material ready for hot rolling, and then preheating to a target hot rolling temperature;

[0016] (3) Hot rolling bonding process;

[0017] The hot rolling bonding procedure includes two types of hot rolling bonding passes, the first type of hot rolling bonding pass is performed first, and then the second type of hot rolling bonding pass is performed; the first type of hot rolling bonding pass is performed from the middle position of the swing roller gap, and the second type of hot rolling bonding pass is performed from the last target parking position of the swing roller gap; the first type of hot rolling bonding pass means starting from the swing roller gap and moving to the left or right end in turn to the target rotation position, stopping and turning, and moving to the middle position (due to the machine accuracy, the middle position ±200mm is the allowable deviation), and then moving to the other end to the target rotation position, stopping and turning, and moving to the target parking position of this pass; the second type of hot rolling bonding pass means starting from the swing roller gap and moving to the left or right end in turn to the target rotation position, stopping and turning, and moving to the other end to the target parking position of this pass;

[0018] The distance between the target rotation position and the nearest end position in the first type of hot rolling bonding pass is recorded as D i , i represents the number of hot rolling bonding passes, exemplary, D 1 represents the distance between the stop and turn position in the first bonding pass and the end position on the nearest side; when i ≥ 2, the distance D between the target turn position and the end position on the nearest side in the first type of hot rolling bonding pass i As the number of bonding passes increases, the difference in the decreasing order is at least 200 mm; D i The minimum value is recorded as D min , the D min Greater than or equal to 500mm; the target parking position of the first type of hot rolling bonding pass is the middle position;

[0019] The distance between any target rotation position in the second type of hot rolling bonding pass and the end position on the nearest side is 20 to 100 mm; the distance between the target parking position in the second type of hot rolling bonding pass and the end position on the nearest side is 20 to 100 mm;

[0020] (4) Hot rolling thinning pass;

[0021] Repeat rolling several times until the target thickness is reached;

[0022] Since the reduction in the hot rolling bonding pass needs to be controlled to be small, the thickness of the material changes very little, and the function of the intermediate pass is to thin the composite plate after successful bonding. Therefore, the hot rolling thinning pass needs to be rolled repeatedly with a large reduction until the target thickness is reached. There is no problem of buckling up and down in the hot rolling thinning pass, so the hot rolling thinning pass can use conventional hot rolling process.

[0023] (5) Post-processing.

[0024] After hot rolling is completed, it can be determined whether cold rolling and annealing are required according to the target work hardening state that the composite material needs to reach. This is a prior art and will not be discussed here. For example, when the customer's delivery state requires an O state, cold rolling is required to anneal the composite plate to an O state. The aluminum alloy composite plates prepared in the present invention are all processed to an O state.

[0025] As the preferred technical solution:

[0026] In the method for preparing the ultra-high composite ratio multi-layer aluminum alloy composite plate for brazing as described above, the number of the first type of hot rolling bonding passes is at least two, and the number of the second type of hot rolling bonding passes is at least two.

[0027] The greater the number of the first type of hot rolling passes, the greater the accumulated downward pressure at the end portion during the first pass of the second type of hot rolling bonding pass, which is more conducive to solving the problem.

[0028] According to the method for preparing a multi-layer aluminum alloy composite plate with an ultra-high composite rate for brazing, the length of the core material ingot is 5000-8700 mm, and the length of the composite cladding ingot is 200-2000 mm shorter than that of the core material ingot; the setting of the length difference should take into account the difference between the elongation after fracture of the composite layer and the elongation after fracture of the core material. The greater the difference, the greater the length difference. Setting the length difference can avoid the problem that the composite layer will not be much longer than the core material after extension during the rolling process, thereby affecting the rolling process;

[0029] During stacking, the core material ingot and the composite cladding ingot are aligned in center, so that there is a length difference of 100 to 1000 mm between the two side ends of the composite cladding and the two side ends of the core layer.

[0030] In the method for preparing a super-high composite multi-layer aluminum alloy composite plate for brazing as described above, the target hot rolling temperature is 0.6 to 0.9 times the solidus temperature of the core material. The setting of the target hot rolling temperature is a well-known technology. For example, when rolling AA3003 material, the preheating temperature can usually be set at 460 to 520°C.

[0031] In the method for preparing a multi-layer aluminum alloy composite plate with ultra-high composite rate for brazing as described above, the reduction amount of a single hot rolling bonding pass is 1 to 8 mm, the reduction amount of the next pass is greater than or equal to the reduction amount of the previous pass; and the total reduction amount of the hot rolling bonding pass is 4 to 20 mm.

[0032] As described above, in the method for preparing a multi-layer aluminum alloy composite plate with ultra-high composite rate for brazing, the target rotation position of any one of the first type of hot rolling bonding passes is 1 / 400mm from the end. i The left and right sides are equal;

[0033] The distance between the target rotation position or target parking position of any pass in the second type of hot rolling bonding passes and the end on the nearest side is, when the target position at one end is set to 20 to 100 mm from the end, the target position at the other end is set to 20 to 100 mm from the end. These edges will be cut off in the end, so it is not required that the target positions at both ends are at the same distance from the end.

[0034] In the method for preparing the ultra-high composite rate multi-layer aluminum alloy composite plate for brazing as described above, the number of the first type of hot rolling bonding passes is two, which are recorded as the first hot rolling bonding pass and the second hot rolling bonding pass in sequence;

[0035] The distance D between the target rotation position and the nearest end position in the first hot rolling bonding pass is 1 1 / 5 to 2 / 5 of the length of the core material ingot, preferably 1 / 4 of the length of the core material ingot;

[0036] The distance D between the target rotation position and the nearest end position in the second hot rolling bonding pass is 2 It is 1 / 9 to 1 / 7 of the length of the core material ingot, preferably 1 / 8 of the length of the core material ingot.

[0037] In the method for preparing the ultra-high composite ratio multi-layer aluminum alloy composite plate for brazing as described above, the post-treatment includes cold rolling and annealing.

[0038] Invention mechanism:

[0039] In order to realize the normal and smooth production of aluminum and aluminum alloy products with ultra-high composite rate multi-layer alloys for brazing during hot rolling, a new composite process is invented. Research has found that the large difference in plasticity is the potential source of the warping or buckling problem of the composite plate produced when the two layers are bonded and hot rolled. The inventors proposed the selection of core materials and composite skin materials to reduce the difference in ductility. However, due to the functional requirements of each layer of material, the ductility between the materials is difficult to reduce to the ideal range. Therefore, the inventors have made process improvements for the important rolling stage of the hot rolling bonding pass that causes processing problems, in order to improve the forming rate of ultra-high composite rate super aluminum alloy composite plates for brazing.

[0040] If the head and tail of the material are bent during the bonding process, the actual pressure reduction of the head and tail parts will become smaller. Compared with the traditional bonding method, the bonding method of the present invention uses a segmented pressure reduction design in the length direction, which solves the problem that the actual pressure reduction of the traditional bonding method is too small when the bonding process is upward or downward, resulting in the head and tail not being able to stick together. This bonding method accumulates the bonding pressure reduction at the head and tail positions, that is, the pressure reduction in the first pass of the second type of hot rolling bonding is actually the sum of the bonding pressure reductions of all previous passes. In this way, the bonding pressure reduction of the head and tail is increased, solving the problem of insufficient pressure reduction at the head and tail caused by bending, resulting in failure to bond.

[0041] Beneficial effects:

[0042] (1) A method for preparing a multi-layer aluminum alloy composite plate with an ultra-high composite rate for brazing of the present invention can realize low scrap rate and stable mass production of the aluminum alloy composite plate with an ultra-high composite rate for brazing;

[0043] (2) The present invention provides a method for preparing a multi-layer aluminum alloy composite plate with an ultra-high composite ratio for brazing. The prepared ultra-high composite ratio aluminum alloy composite plate for brazing has high strength, long life and lightweight effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 This is a schematic diagram of the brazing of the ultra-high composite ratio aluminum alloy composite plate of Example 3;

[0045] Figure 2 This is a schematic diagram of the first hot rolling bonding pass of Example 1;

[0046] Figure 3 This is a schematic diagram of the second hot rolling bonding pass of Example 1;

[0047] Figure 4 This is a schematic diagram of the third hot rolling bonding pass of Example 1;

[0048] Figure 5 Schematic diagram of the fourth hot rolling bonding pass of Example 1;

[0049] Among them, 1-core material, 2-brazing layer, 3-intermediate material. DETAILED DESCRIPTION

[0050] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0051] The test methods involved in the performance indicators of the present invention are as follows:

[0052] (1) Scrap rate: During the rolling process of composite plates, warping or buckling problems may occur in the bonding stage and the intermediate pass stage. When warping or buckling problems occur, rolling cannot be continued, resulting in scrapping; the scrap rate is calculated as the number of scrapped blocks in 100 composite ingots during hot rolling / 100*100%.

[0053] (2) Strength characterization: Determine the tensile strength Rm and elongation after fracture A according to GB / T 228.1-2021 50mm .

[0054] (3) Corrosion characterization: The corrosion is evaluated using the OY corrosion test. After the sample with a size of 20mm*150mm is immersed in the OY corrosion solution, it is considered qualified if there is no leakage or perforation. OY test temperature cycle: Stir at 88℃ for 8 hours, stirring speed 0.8m / s; then stand at room temperature (25℃) for 16 hours; the OY test cycle days are 125 days. The composition of the OY corrosion solution is as follows:

[0055] Reagents NaCl <![CDATA[Na 2 SO 4 ]]> <![CDATA[CuCl 2 ·2H 2 Or]]> <![CDATA[FeCl 3 ·6H 2 O]]> concentration 224.44mg / L 88.8mg / L 2.65mg / L 145.32mg / L

[0056] The alloy and material performance level information of the aluminum alloy used in the embodiments of the present invention is as follows:

[0057] Core material:

[0058] C1 (5 series improved aluminum alloy): Si 1.2wt%, Fe 0.48wt%, Mn 1.08wt%, Cu 0.55wt%, Mg4.42wt%, Zn 0.01wt%, Ti 0.02wt%, Zr 0.01wt%; the tensile strength of C1 aluminum alloy is 300MPa, the elongation after fracture is 5%, and the solidus temperature is 652℃.

[0059] C2 (3 series improved aluminum alloy): Si 0.53wt%, Fe 0.42wt%, Mn 1.15wt%, Cu 0.81wt%, Mg 0.02wt%, Zn 0.12wt%, Ti 0.02wt%, Zr 0.06wt%; the tensile strength of C2 aluminum alloy is 150MPa, the elongation after fracture is 24%, and the solidus temperature is 672℃.

[0060] C3 (5 series improved aluminum alloy): Si 0.23wt%, Fe 0.35wt%, Mn 0.88wt%, Cu 0.01wt%, Mg 2.25wt%, Zn 0.03wt%, Ti 0.02wt%, Zr 0.01wt%; the tensile strength of C3 aluminum alloy is 210MPa, the elongation after fracture is 22%, and the solidus temperature is 657℃.

[0061] C4 (6 series improved aluminum alloy): Si 0.73wt%, Fe 0.29wt%, Mn 0.11wt%, Cu 0.15wt%, Mg 0.92wt%, Zn 0.02wt%, Ti 0.02wt%, Zr 0.01wt%; the tensile strength of C4 aluminum alloy is 132MPa, the elongation after fracture is 25%, and the solidus temperature is 662℃.

[0062] Intermediate material:

[0063] Z1 (3 series improved aluminum alloy): Si 0.35wt%, Fe 0.14wt%, Mn 1.77wt%, Cu 0.01wt%, Mg 0.01wt%, Zn 0.01wt%, Ti 0.02wt%, Zr 0.01wt%; the tensile strength of Z1 aluminum alloy is 132MPa and the elongation after fracture is 33%.

[0064] Z2 (3 series improved aluminum alloy): Si 0.43wt%, Fe 0.01wt%, Mn 0.52wt%, Cu 0.01wt%, Mg 0.01wt%, Zn 0.01wt%, Ti 0.02wt%, Zr 0.01wt%; the tensile strength of Z2 aluminum alloy is 102MPa and the elongation after fracture is 38%.

[0065] Z3 (7 series improved aluminum alloy): Si 0.11wt%, Fe 0.22wt%, Mn 0.9wt%, Cu 0.01wt%, Mg0.01wt%, Zn 1.18wt%, Ti 0.02wt%, Zr 0.01wt%; the tensile strength of Z3 aluminum alloy is 98MPa and the elongation after fracture is 35%.

[0066] Brazing materials:

[0067] F1 (4 series improved aluminum alloy): Si 7.68wt%, Fe 0.11wt%, Mn 0.01wt%, Cu 0.01wt%, Mg 0.01wt%, Zn 0.01wt%, Ti 0.01wt%, Zr 0.01wt%; the tensile strength of F1 aluminum alloy is 118MPa and the elongation after fracture is 35%.

[0068] F2 (4 series improved aluminum alloy): Si 9.79wt%, Fe 0.19wt%, Mn 0.01wt%, Cu 0.01wt%, Mg 0.01wt%, Zn 0.01wt%, Ti 0.01wt%, Zr 0.01wt%; the tensile strength of F2 aluminum alloy is 123MPa, and the elongation after fracture is 33%.

[0069] F3 (4 series improved aluminum alloy): Si 7.66wt%, Fe 0.1wt%, Mn 0.01wt%, Cu 0.01wt%, Mg0.01wt%, Zn 0.12wt%, Ti 0.01wt%, Zr 0.01wt%; the tensile strength of F3 aluminum alloy is 116MPa and the elongation after fracture is 36%.

[0070] F4 (4 series improved aluminum alloy): Si 6.2wt%, Fe 0.12wt%, Mn 0.01wt%, Cu 0.01wt%, Mg0.01wt%, Zn 0.01wt%, Ti 0.01wt%, Zr 0.01wt%; the tensile strength of F4 aluminum alloy is 106MPa and the elongation after fracture is 40%.

[0071] The thickness of the cold-rolled finished product and the annealing treatment state usually depend on customer requirements. In the following embodiments and comparative examples, the target cold-rolled thickness is 0.8 mm, and the treatment state is O state. The final thickness and state of the material do not affect the contribution of the present invention on the basis of the prior art.

[0072] Example 1

[0073] A method for preparing an ultra-high composite rate multi-layer aluminum alloy composite plate for brazing, wherein the aluminum alloy composite plate comprises a core material and a composite cladding located on one side of the core material, wherein the composite cladding is composed of an intermediate material and a brazing material, wherein one side of the intermediate material is in contact with the core material, and the other side is in contact with the brazing material; during preparation, the core material ingot length is 8650 mm; the composite cladding ingot length is 6850 mm; and the specific preparation steps are as follows:

[0074] (1) Preparation of rolling objects;

[0075] Core material: C1; Intermediate material: Z1; Brazing material: F3; The difference in elongation after fracture between the core material and the intermediate material is 28%; The difference in elongation after fracture between the intermediate material and the brazing material is 3%;

[0076] (2) Preheating;

[0077] The core material ingot and the composite cladding ingot are stacked into a laminated material ready for hot rolling, wherein the core material ingot and the composite cladding ingot are aligned in the center during stacking, and then preheated to a target hot rolling temperature of 482°C;

[0078] There is a 900mm length difference between the ends of both sides of the composite cladding and the ends of both sides of the core layer;

[0079] (3) Hot rolling bonding process;

[0080] The hot rolling bonding procedure includes a first hot rolling bonding pass, a second hot rolling bonding pass, a third hot rolling bonding pass and a fourth hot rolling bonding pass; the first hot rolling bonding pass and the second hot rolling bonding pass are first-type hot rolling bonding passes, and the roll gap is swung from the middle position; the third hot rolling bonding pass and the fourth hot rolling bonding pass are second-type hot rolling bonding passes, and the roll gap is swung from the last target parking position;

[0081] (3.1) Figure 2 As shown, the first hot rolling bonding pass is to start from the middle position and move to the left end to the target rotation position, stop and turn, move to the middle position, then move to the right end to the target rotation position, stop and turn, and then move to the middle position to stop;

[0082] The distance D between the two target rotation positions and the nearest end position is 1 The length of the core material ingot is 1 / 4; the reduction of the first hot rolling bonding pass is 1mm;

[0083] (3.2) Figure 3 As shown, the second hot rolling bonding pass is to start from the middle position and move to the right end to the target rotation position, stop and turn, move to the middle position, then move to the left end to the target rotation position, stop and turn, and then move to the middle position and stop;

[0084] The distance D between the two target rotation positions and the nearest end position is 2 The length of the core material ingot is 1 / 8; the reduction of the second hot rolling bonding pass is 2 mm;

[0085] (3.3) Figure 4 As shown, the third hot rolling bonding pass is to start from the middle position and move to the left end to the target rotation position, stop and turn, and then move to the right end to the target position and stop;

[0086] Among them, the distance between the left end target rotation position and the leftmost end position is 50mm; the distance between the right end target parking position and the rightmost end position is 50mm; the reduction amount of the third hot rolling bonding pass is 3mm;

[0087] (3.4) Figure 5 As shown, the fourth hot rolling bonding pass means driving from the last target position parking position to the left end to the target rotation position, parking and rotating, and then driving to the right end to the target position;

[0088] Among them, the distance between the left end target rotation position and the leftmost end position is 50mm; the distance between the right end target parking position and the rightmost end position is 50mm; the reduction amount of the fourth hot rolling bonding pass is 4mm;

[0089] (4) Hot rolling thinning pass;

[0090] Repeat the rolling process several times until the target thickness of 5 mm is reached;

[0091] (5) Post-processing;

[0092] Cold rolled and annealed.

[0093] The composite rate of the brazing material in the finally prepared ultra-high composite rate multi-layer aluminum alloy composite plate for brazing is 14%, the composite rate of the intermediate material is 24%, and the composite rate of the core material is 62%; the tensile strength of the ultra-high composite rate multi-layer aluminum alloy composite plate for brazing is 275MPa, the scrap rate is 2%, and the corrosion test is qualified.

[0094] Comparative Example 1

[0095] A method for preparing a multilayer aluminum alloy composite plate for brazing is basically the same as Example 1, except that the intermediate material is Z2, that is, the difference in elongation after fracture between the intermediate material and the core material is 33%, and the difference in elongation after fracture between the intermediate material and the brazing material is 2%.

[0096] The tensile strength of the finally prepared multi-layer aluminum alloy composite plate for brazing is 268 MPa, and the scrap rate is 66%.

[0097] By comparing Comparative Example 1 with Example 1, it can be found that the probability of scrapping due to failure of edge bonding during the bonding process of Comparative Example 1 is higher. This is because the ductility of the selected core layer material and the middle layer material is too different, resulting in excessive difference in deformation of each layer of alloy during hot rolling. This is the root cause of serious warping or buckling problems in the composite process. The maximum difference achieved in existing experiments is 28%.

[0098] Comparative Example 2

[0099] A method for preparing a multi-layer aluminum alloy composite plate for brazing is basically the same as that of Example 1, except that the brazing material is F4, that is, the difference in elongation after fracture between the intermediate material and the brazing material is 7%.

[0100] The tensile strength of the finally prepared multi-layer aluminum alloy composite plate for brazing is 272 MPa, and the scrap rate is 75%.

[0101] By comparing Comparative Example 2 with Example 1, it can be found that the edges of Comparative Example 2 cannot be bonded during the bonding process, resulting in a high scrap rate. This is because the intermediate material and the brazing material are unreasonable matched. The intermediate material and the brazing material are both high ductility materials and are close to the outside of the composite layer. The large difference in material ductility can easily lead to problems of edge warping or buckling.

[0102] Comparative Example 3

[0103] A method for preparing a multi-layer aluminum alloy composite plate for brazing is basically the same as that of Example 1, except that the length difference between the ends of the composite cladding and the ends of the core layer is 50 mm.

[0104] The tensile strength of the finally prepared multi-layer aluminum alloy composite plate for brazing is 276 MPa, and the scrap rate is 68%.

[0105] By comparing Comparative Example 3 with Example 1, it can be found that the scrap rate of Comparative Example 3 is too high. This is because the length difference between the two side ends of the composite cladding and the two side ends of the core layer is set too small, and the difference between the elongation after fracture of the composite layer and the elongation after fracture of the core material is not fully considered, resulting in the composite layer being much longer than the core material after extension during the rolling process, thereby affecting the rolling quality and increasing the scrap rate.

[0106] Comparative Example 4

[0107] A method for preparing a multi-layer aluminum alloy composite plate for brazing is basically the same as Example 1, except that the target rotation positions of the first hot rolling bonding pass, the second hot rolling bonding pass and the third hot rolling bonding pass are the same, all of which are 50 mm from the end position, that is, the distance between the position where the first hot rolling bonding pass, the second hot rolling bonding pass and the third hot rolling bonding pass stop and rotate and the end position on the nearest side does not decrease in sequence with increasing pass number.

[0108] The tensile strength of the finally prepared multi-layer aluminum alloy composite plate for brazing is 274 MPa, and the scrap rate is 22%.

[0109] By comparing Comparative Example 4 with Example 1, it can be found that the scrap rate of the comparative example is too high, while the scrap rate of Example 1 is extremely small. This is because the bonding method of Example 1 accumulates the bonding reduction at the head and tail positions, that is, in the third pass (the first pass of the second type of hot-rolled bonding), the reduction obtained at the edge is actually the sum of the bonding reductions of all previous passes; in this way, the bonding reduction at the head and tail becomes larger, which solves the problem of insufficient head and tail reduction caused by bending, resulting in failure of bonding.

[0110] Example 2

[0111] A method for preparing a multi-layer aluminum alloy composite plate for brazing is basically the same as Example 1, except that the target rotation position of the second hot rolling bonding pass and the third hot rolling bonding pass are the same, that is, the distance between the target rotation position of the second hot rolling bonding pass and the end position on the nearest side is 50 mm.

[0112] The tensile strength of the finally prepared multi-layer aluminum alloy composite plate for brazing is 274 MPa, the scrap rate is 15%, and the corrosion test is qualified.

[0113] Example 3

[0114] A method for preparing a multi-layer aluminum alloy composite plate with ultra-high composite rate for brazing is basically the same as that in Example 1, such as Figure 1 As shown, the only difference is that the other side of the core material also contains brazing material II, and the brazing material II is F3.

[0115] In the finally obtained ultra-high composite rate multi-layer aluminum alloy composite plate for brazing, the composite rate of the brazing material 2 on one side is 10%, the composite rate of the intermediate material 3 is 25%, the composite rate of the core material 1 is 50%, and the composite rate of the brazing material II on the other side is 15%; the tensile strength of the ultra-high composite rate multi-layer aluminum alloy composite plate for brazing is 268MPa, the scrap rate is 4%, and the corrosion test is qualified.

[0116] Example 4

[0117] A method for preparing an ultra-high composite rate multi-layer aluminum alloy composite plate for brazing is basically the same as Example 1. The aluminum alloy composite plate includes a core material and a composite cladding located on both sides of the core material, and the composite cladding on the other side is composed of an intermediate material II and a brazing material II, the intermediate material II is Z1, and the brazing material II is F3.

[0118] In the finally obtained ultra-high composite rate multi-layer aluminum alloy composite plate for brazing, the composite rate of the brazing material on one side is 15%, the composite rate of the intermediate material is 25%, the composite rate of the core material is 20%, the composite rate of the intermediate material II on the other side is 25%, and the composite rate of the brazing material II is 15%; the tensile strength of the ultra-high composite rate multi-layer aluminum alloy composite plate for brazing is 271MPa, the scrap rate is 1%, and the corrosion test is qualified.

[0119] Example 5

[0120] A method for preparing an ultra-high composite rate multi-layer aluminum alloy composite plate for brazing, wherein the aluminum alloy composite plate comprises a core material and a composite cladding located on one side of the core material, wherein the composite cladding is composed of an intermediate material and a brazing material, wherein one side of the intermediate material is in contact with the core material, and the other side is in contact with the brazing material; during preparation, the core material ingot length is 6610 mm; the composite cladding ingot length is 5400 mm; and the specific preparation steps are as follows:

[0121] (1) Preparation of rolling objects;

[0122] Core material: C2; Intermediate material: Z1; Brazing material: F1; The difference in elongation after fracture between the core material and the intermediate material is 9%; The difference in elongation after fracture between the intermediate material and the brazing material is 2%;

[0123] (2) Preheating;

[0124] The core material ingot and the composite cladding ingot are stacked into a laminated material ready for hot rolling, wherein the core material ingot and the composite cladding ingot are aligned in the center during stacking, and then preheated to a target hot rolling temperature of 492°C;

[0125] Among them, there is a length difference of 605mm between the ends of both sides of the composite cladding and the ends of both sides of the core layer;

[0126] (3) Hot rolling bonding process;

[0127] The hot rolling bonding procedure includes the first hot rolling bonding pass, the second hot rolling bonding pass, the third hot rolling bonding pass, the fourth hot rolling bonding pass, the fifth hot rolling bonding pass and the sixth hot rolling bonding pass; the first hot rolling bonding pass, the second hot rolling bonding pass and the third hot rolling bonding pass are first-type hot rolling bonding passes, and the roll gap is swung from the middle position; the fourth hot rolling bonding pass, the fifth hot rolling bonding pass and the sixth hot rolling bonding pass are second-type hot rolling bonding passes, and the roll gap is swung from the last target parking position;

[0128] (3.1) The first hot rolling bonding pass means starting from the middle position and moving to the right end to the target rotation position, stopping and turning, moving to the middle position, then moving to the left end to the target rotation position, stopping and turning, and then moving to the middle position;

[0129] The distance D between the two target rotation positions and the nearest end position is 1 The length of the core material ingot is 1 / 4; the reduction of the first hot rolling bonding pass is 1mm;

[0130] (3.2) The second hot rolling bonding pass means starting from the middle position and moving to the left end to the target rotation position, stopping and turning, moving to the middle position, then moving to the right end to the target rotation position, stopping and turning, and then moving to the middle position;

[0131] The distance D between the two target rotation positions and the nearest end position is 2 The length of the core material ingot is 1 / 8. The reduction of the second hot rolling bonding pass is 1 mm.

[0132] (3.3) The third hot rolling bonding pass means starting from the middle position and moving to the right end to the target rotation position, stopping and turning, moving to the middle position, then moving to the left end to the target rotation position, stopping and turning, and moving to the middle position again;

[0133] The distance between the two parking positions and the nearest end position is D 3 The reduction of the third hot rolling bonding pass is 2 mm;

[0134] (3.4) The fourth hot rolling bonding pass is to start from the middle position and move to the right end to the target turning position, stop and turn, and then move to the left end to the target parking position;

[0135] Among them, the distance between the right end target rotation position and the rightmost end position is 100mm; the distance between the left end target parking position and the leftmost end position is 100mm; the reduction amount of the fourth hot rolling bonding pass is 3mm;

[0136] (3.5) The fifth hot rolling bonding pass means starting from the parking position at the last target position and moving to the right end to the target turning position, stopping and turning, and then moving to the left end to the target position;

[0137] Among them, the distance between the right end target rotation position and the rightmost end position is 50mm; the distance between the left end target parking position and the leftmost end position is 50mm; the reduction amount of the fifth hot rolling bonding pass is 3mm;

[0138] (3.6) The sixth hot rolling bonding pass means starting from the parking position at the last target position and moving to the right end to the target turning position, stopping and turning, and then moving to the left end to the target position;

[0139] Among them, the distance between the right end target rotation position and the rightmost end position is 50mm; the distance between the left end target parking position and the leftmost end position is 50mm; the reduction amount of the sixth hot rolling bonding pass is 4mm;

[0140] (4) Hot rolling thinning pass;

[0141] Repeat the rolling process several times until the target thickness of 4 mm is reached;

[0142] (5) Post-processing;

[0143] Cold rolled and annealed.

[0144] The composite rate of the brazing material in the finally prepared ultra-high composite rate multi-layer aluminum alloy composite plate for brazing is 11%, the composite rate of the intermediate material is 28%, and the composite rate of the core material is 61%; the tensile strength of the ultra-high composite rate multi-layer aluminum alloy composite plate for brazing is 167MPa, the scrap rate is 0%, and the corrosion test is qualified.

[0145] Example 6

[0146] A method for preparing an ultra-high composite rate multi-layer aluminum alloy composite plate for brazing, wherein the aluminum alloy composite plate comprises a core material and a composite cladding located on one side of the core material, wherein the composite cladding is composed of an intermediate material and a brazing material, wherein one side of the intermediate material is in contact with the core material, and the other side is in contact with the brazing material; during preparation, the core material ingot length is 7600 mm; the composite cladding ingot length is 6500 mm; the specific preparation steps are as follows:

[0147] (1) Preparation of rolling objects;

[0148] Core material: C3; Intermediate material: Z2; Brazing material: F2; The difference in elongation after fracture between the core material and the intermediate material is 16%; The difference in elongation after fracture between the intermediate material and the brazing material is 5%;

[0149] (2) Preheating;

[0150] The core material ingot and the composite cladding ingot are stacked into a laminated material ready for hot rolling, wherein the core material ingot and the composite cladding ingot are aligned in the center during stacking, and then preheated to a target hot rolling temperature of 485°C;

[0151] There is a length difference of 550 mm between the ends of both sides of the composite cladding and the ends of both sides of the core layer;

[0152] (3) Hot rolling bonding process;

[0153] The hot rolling bonding procedure includes a first hot rolling bonding pass, a second hot rolling bonding pass, a third hot rolling bonding pass and a fourth hot rolling bonding pass; the first hot rolling bonding pass and the second hot rolling bonding pass are first-type hot rolling bonding passes, and the roll gap is swung from the middle position; the third hot rolling bonding pass and the fourth hot rolling bonding pass are second-type hot rolling bonding passes, and the roll gap is swung from the last target parking position;

[0154] (3.1) The first hot rolling bonding pass means starting from the middle position and moving to the right end to the target rotation position, stopping and turning, moving to the middle position, then moving to the left end to the target rotation position, stopping and turning, and then moving to the middle position;

[0155] The distance D between the two target rotation positions and the nearest end position is 1 The length of the core material ingot is 1 / 5; the reduction of the first hot rolling bonding pass is 2 mm;

[0156] (3.2) The second hot rolling bonding pass means starting from the middle position and moving to the left end to the target rotation position, stopping and turning, moving to the middle position, then moving to the right end to the target rotation position, stopping and turning, and then moving to the middle position;

[0157] The distance D between the two target rotation positions and the nearest end position is 2 The length of the core material ingot is 1 / 7; the reduction of the second hot rolling bonding pass is 4mm;

[0158] (3.3) The third hot rolling bonding pass is to start from the middle position and move to the right end to the target turning position, stop and turn, then move to the left end to the target position and stop;

[0159] Among them, the distance between the right end target rotation position and the rightmost end position is 20mm, and the distance between the left end target parking position and the leftmost end position is 100mm; the reduction amount of the third hot rolling bonding pass is 6mm;

[0160] (3.4) The fourth hot rolling bonding pass means starting from the parking position at the last target position and moving to the right end to the target turning position, stopping and turning, and then moving to the left end to the target position;

[0161] Among them, the distance between the right end target rotation position and the rightmost end position is 30mm, and the distance between the left end target parking position and the leftmost end position is 30mm; the reduction amount of the fourth hot rolling bonding pass is 8mm;

[0162] (4) Hot rolling thinning pass;

[0163] Repeat the rolling process several times until the target thickness is reached, 6 mm;

[0164] (5) Post-processing;

[0165] Cold rolled and annealed.

[0166] The composite rate of the brazing material in the finally prepared ultra-high composite rate multi-layer aluminum alloy composite plate for brazing is 10%, the composite rate of the intermediate material is 30%, and the composite rate of the core material is 60%; the tensile strength of the ultra-high composite rate multi-layer aluminum alloy composite plate for brazing is 199MPa, the scrap rate is 1%, and the corrosion test is qualified.

[0167] Example 7

[0168] A method for preparing an ultra-high composite rate multi-layer aluminum alloy composite plate for brazing, wherein the aluminum alloy composite plate comprises a core material and a composite cladding located on one side of the core material, wherein the composite cladding is composed of an intermediate material and a brazing material, wherein one side of the intermediate material is in contact with the core material, and the other side is in contact with the brazing material; during preparation, the core material ingot length is 7200 mm; the composite cladding ingot length is 6160 mm; the specific preparation steps are as follows:

[0169] (1) Preparation of rolling objects;

[0170] Core material: C4; Intermediate material: Z3; Brazing material: F3; The difference in elongation after fracture between the core material and the intermediate material is 10%; The difference in elongation after fracture between the intermediate material and the brazing material is 1%;

[0171] (2) Preheating;

[0172] The core material ingot and the composite cladding ingot are stacked into a laminated material ready for hot rolling, and then preheated to a target hot rolling temperature of 501°C;

[0173] (3) Hot rolling bonding process;

[0174] The hot rolling bonding procedure includes a first hot rolling bonding pass, a second hot rolling bonding pass, a third hot rolling bonding pass and a fourth hot rolling bonding pass; the first hot rolling bonding pass and the second hot rolling bonding pass are first-type hot rolling bonding passes, and the roll gap is swung from the middle position; the third hot rolling bonding pass and the fourth hot rolling bonding pass are second-type hot rolling bonding passes, and the roll gap is swung from the last target parking position;

[0175] (3.1) The first hot rolling bonding pass means starting from the middle position and moving to the right end to the target rotation position, stopping and turning, moving to the middle position, then moving to the left end to the target rotation position, stopping and turning, and then moving to the middle position;

[0176] The distance D between the two target rotation positions and the nearest end position is 1 The length of the core material ingot is 2 / 5. The reduction of the first hot rolling bonding pass is 1 mm.

[0177] (3.2) The second hot rolling bonding pass means starting from the middle position and moving to the left end to the target rotation position, stopping and turning, moving to the middle position, then moving to the right end to the target rotation position, stopping and turning, and then moving to the middle position;

[0178] The distance D between the two target rotation positions and the nearest end position is 2 The length of the core material ingot is 1 / 9. The reduction of the second hot rolling bonding pass is 1 mm.

[0179] (3.3) The third hot rolling bonding pass is to start from the middle position and move to the right end to the target turning position, stop and turn, then move to the left end to the target position and stop;

[0180] Among them, the distance between the right end target rotation position and the rightmost end position is 100mm, and the distance between the left end target parking position and the leftmost end position is 80mm; the reduction amount of the third hot rolling bonding pass is 1mm;

[0181] (3.4) The fourth hot rolling bonding pass means starting from the last target position parking position and moving to the right end to the target position, stopping and turning, moving to the middle position, and then moving to the left end to the target position;

[0182] Among them, the distance between the right end target rotation position and the rightmost end position is 100mm; the distance between the left end target parking position and the leftmost end position is 100mm; the reduction amount of the fourth hot rolling bonding pass is 1mm;

[0183] (4) Hot rolling thinning pass;

[0184] Repeat the rolling process several times until the target thickness is reached, 7 mm;

[0185] (5) Post-processing;

[0186] Cold rolled and annealed.

[0187] The composite rate of the brazing material in the finally prepared ultra-high composite rate multi-layer aluminum alloy composite plate for brazing is 6%, the composite rate of the intermediate material is 32%, and the composite rate of the core material is 62%; the tensile strength of the ultra-high composite rate multi-layer aluminum alloy composite plate for brazing is 108MPa, the scrap rate is 0%, and the corrosion test is qualified.

[0188] Example 8

[0189] A method for preparing an ultra-high composite rate multi-layer aluminum alloy composite plate for brazing, wherein the aluminum alloy composite plate comprises a core material and a composite cladding located on one side of the core material, wherein the composite cladding is composed of an intermediate material and a brazing material, wherein one side of the intermediate material is in contact with the core material, and the other side is in contact with the brazing material; during preparation, the core material ingot length is 6800 mm; the composite cladding ingot length is 5800 mm; and the specific preparation steps are as follows:

[0190] (1) Preparation of rolling objects;

[0191] Core material: C2; Intermediate material: Z2; Brazing material: F2; The difference in elongation after fracture between the core material and the intermediate material is 14%; The difference in elongation after fracture between the intermediate material and the brazing material is 5%;

[0192] (2) Preheating;

[0193] The core material ingot and the composite cladding ingot are stacked into a laminated material ready for hot rolling, and then preheated to a target hot rolling temperature of 499°C;

[0194] (3) Hot rolling bonding process;

[0195] The hot rolling bonding procedure includes a first hot rolling bonding pass, a second hot rolling bonding pass, a third hot rolling bonding pass and a fourth hot rolling bonding pass; the first hot rolling bonding pass and the second hot rolling bonding pass are first-type hot rolling bonding passes, and the roll gap is swung from the middle position; the third hot rolling bonding pass and the fourth hot rolling bonding pass are second-type hot rolling bonding passes, and the roll gap is swung from the last target parking position;

[0196] (3.1) The first hot rolling bonding pass means starting from the middle position and moving to the right end to the target rotation position, stopping and turning, moving to the middle position, then moving to the left end to the target rotation position, stopping and turning, and then moving to the middle position and stopping;

[0197] The distance D between the two target rotation positions and the nearest end position is 1 The length of the core material ingot is 1 / 4. The reduction of the first hot rolling bonding pass is 1 mm.

[0198] (3.2) The second hot rolling bonding pass means starting from the middle position and moving to the left end to the target rotation position, stopping and turning, moving to the middle position, then moving to the right end to the target rotation position, stopping and turning, and then moving to the middle position;

[0199] The distance D between the two target rotation positions and the nearest end position is 2 The length of the core material ingot is 1 / 8. The reduction of the second hot rolling bonding pass is 1 mm.

[0200] (3.3) The third hot rolling bonding pass is to start from the middle position and move to the right end to the target turning position, stop and turn, then move to the left end to the target position and stop;

[0201] Among them, the distance between the right end target rotation position and the rightmost end position is 100mm, and the distance between the left end target parking position and the leftmost end position is 100mm; the reduction amount of the third hot rolling bonding pass is 1mm;

[0202] (3.4) The fourth hot rolling bonding pass means starting from the last target position parking position and moving to the left end to the target turning position, stopping and turning, and then moving to the right end to the target position and stopping;

[0203] Among them, the distance between the right end target rotation position and the rightmost end position is 80mm, and the distance between the left end target parking position and the leftmost end position is 60mm; the reduction amount of the fourth hot rolling bonding pass is 1mm;

[0204] (4) Hot rolling thinning pass;

[0205] Repeat the rolling process several times until the target thickness is reached, 7 mm;

[0206] (5) Post-processing;

[0207] Cold rolled and annealed.

[0208] The composite rate of the brazing material in the finally prepared ultra-high composite rate multi-layer aluminum alloy composite plate for brazing is 6%, the composite rate of the intermediate material is 32%, and the composite rate of the core material is 62%; the tensile strength of the ultra-high composite rate multi-layer aluminum alloy composite plate for brazing is 108MPa, the scrap rate is 1%, and the corrosion test is qualified.

Claims

1. A method for preparing an ultra-high composite rate multi-layer aluminum alloy composite plate for brazing, wherein the aluminum alloy composite plate comprises a core material and a composite cladding layer at least located on one side of the core material, wherein the composite cladding layer is composed of an intermediate material and a brazing material, wherein one side of the intermediate material is in contact with the core material, and the other side is in contact with the brazing material, wherein: The composite rate of the brazing material is 5-15%, the composite rate of the intermediate material is ≥22%, and the thickness ratio of the single-sided composite cladding to the core material is within 2:1; the preparation of the aluminum alloy composite plate includes the following steps: (1) Preparation of rolling objects; The core material is an aluminum alloy with a tensile strength of 120-300 MPa and an elongation after fracture of 5-25%; The difference in elongation after fracture between the intermediate material and the core material is 9-28%, and the difference in elongation after fracture between the intermediate material and the brazing material is ≤5%; (2) Preheating; stacking the core material ingot and the composite cladding ingot into a laminated material ready for hot rolling, and then preheating to a target hot rolling temperature; (3) Hot rolling bonding process; The hot rolling bonding procedure includes two types of hot rolling bonding passes, the first type of hot rolling bonding pass is performed first, and then the second type of hot rolling bonding pass is performed; the first type of hot rolling bonding pass is a swing roll gap from the middle position, and the second type of hot rolling bonding pass is a swing roll gap from the last target parking position; the first type of hot rolling bonding pass means starting from the swing roll gap and moving to the left or right end in turn to the target rotation position, stopping and turning, moving to the middle position, and then moving to the other end to the target rotation position, stopping and turning, and moving to the target parking position of this pass; the second type of hot rolling bonding pass means starting from the swing roll gap and moving to the left or right end in turn to the target rotation position, stopping and turning, and moving to the other end to the target parking position of this pass; The distance between the target rotation position and the nearest end position in the first type of hot rolling bonding pass is recorded as D i , i represents the number of hot rolling bonding passes; when i ≥ 2, the distance D between the target rotation position and the end position on the nearest side in the first type of hot rolling bonding pass i As the number of bonding passes increases, the difference in the decreasing order is at least 200 mm; D i The minimum value is recorded as D min , the D min Greater than or equal to 500mm; the target parking position of the first type of hot rolling bonding pass is the middle position; The distance between any target rotation position in the second type of hot rolling bonding pass and the end position on the nearest side is 20 to 100 mm; the distance between the target parking position in the second type of hot rolling bonding pass and the end position on the nearest side is 20 to 100 mm; (4) Hot rolling thinning pass; Repeat rolling several times until the target thickness is reached; (5) Post-processing.

2. The method for preparing a super-high composite multi-layer aluminum alloy composite plate for brazing according to claim 1, characterized in that: The number of the first type of hot rolling bonding passes is at least two, and the number of the second type of hot rolling bonding passes is at least two.

3. The method for preparing a super-high composite rate multi-layer aluminum alloy composite plate for brazing according to claim 1, characterized in that: The length of the core material ingot is 5000-8700 mm, and the length of the composite cladding ingot is 200-2000 mm shorter than that of the core material ingot; During stacking, the core material ingot and the composite cladding ingot are aligned in center.

4. The method for preparing a super-high composite rate multi-layer aluminum alloy composite plate for brazing according to claim 2 or 3, characterized in that: The target hot rolling temperature is 0.6 to 0.9 times the solidus temperature of the core material.

5. The method for preparing a super-high composite rate multi-layer aluminum alloy composite plate for brazing according to claim 4, characterized in that: The reduction amount of a single hot rolling bonding pass is 1 to 8 mm, and the reduction amount of the next pass is greater than or equal to the reduction amount of the previous pass; the total reduction amount of the hot rolling bonding passes is 4 to 20 mm.

6. The method for preparing a super-high composite multi-layer aluminum alloy composite plate for brazing according to claim 5, characterized in that: The target rotation position of any one of the first type of hot rolling bonding passes is the distance D from the end i The left and right sides are equal; the distance between the target rotation position or target parking position of any pass in the second type of hot rolling bonding pass and the end on the nearest side is that when the target position at one end is set to 20 to 100 mm from the end, the target position at the other end is set to 20 to 100 mm from the end.

7. The method for preparing a super-high composite multi-layer aluminum alloy composite plate for brazing according to claim 6, characterized in that: The number of the first type of hot rolling bonding passes is two, which are recorded as the first hot rolling bonding pass and the second hot rolling bonding pass respectively; The distance D1 between the target rotation position and the end position on the nearest side in the first hot rolling bonding pass is 1 / 5 to 2 / 5 of the length of the core material ingot; The distance D2 between the target rotation position and the nearest end position in the second hot rolling bonding pass is 1 / 9 to 1 / 7 of the length of the core material ingot.

8. The method for preparing a super-high composite multi-layer aluminum alloy composite plate for brazing according to claim 1, characterized in that: The post-treatment includes cold rolling and annealing.

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