Ultrasonic-assisted different-temperature rolling method for aluminum / magnesium / aluminum three-layer composite board

Abstract

The invention belongs to the technical field of metal composite material preparation, and relates to an ultrasonic-assisted different-temperature aluminum / magnesium / aluminum three-layer composite plate rolling method which comprises the following steps: pretreating a magnesium plate and two pretreated aluminum strips; heating in an induction coil heating furnace to obtain a heated magnesium plate, and welding and sealing edges to obtain two coiled combined aluminum strips; preparing an aluminum / magnesium / aluminum three-layer plate blank; and ultrasonic waves are applied to the rollers, the aluminum / magnesium / aluminum three-layer plate blank is rolled through the upper roller and the lower roller, and the aluminum / magnesium / aluminum three-layer composite plate is obtained. The magnesium plate is heated through the induction coil, the aluminum strip is not heated, so that different-temperature rolling is achieved between the magnesium plate and the aluminum plate, the plasticity difference caused by performance difference of magnesium and aluminum materials can be reduced, an oxide layer on the surface of to-be-bonded metal is broken by applying ultrasonic waves to the roller, and the bonding quality of the to-be-bonded metal is improved. Therefore, dissimilar metals with large plasticity difference are fully combined, and the defects of holes, cracks and the like of the aluminum / magnesium / aluminum three-layer composite board on a composite interface are avoided.

Description

Technical Field

[0001] The invention belongs to the technical field of metal composite material preparation, and relates to a method for ultrasonically assisted different-temperature rolling of an aluminum / magnesium / aluminum three-layer composite plate. Background Art

[0002] Layered metal composite materials are made of two or more component metals and have excellent properties that cannot be met by a single metal material. They have broad application prospects in the current era of rapid development of emerging industries. Magnesium alloy is the lightest metal among current structural materials, with a series of advantages such as low density, high specific strength, and radiation resistance, but its poor corrosion resistance seriously restricts its wide application in aerospace, automotive industry, 3C products and other fields. Aluminum alloy is light in weight and has good corrosion resistance, and has good plastic deformation ability, which is suitable for a variety of processing and forming processes. Therefore, metal aluminum with excellent corrosion resistance is coated on the upper and lower surfaces of metal magnesium to form an aluminum / magnesium / aluminum three-layer composite plate. The composite plate has the advantages of light weight, high strength and corrosion resistance, and has good application prospects in aerospace, petrochemical, transportation and daily life.

[0003] At present, the methods for preparing metal composite plates include extrusion composite method, rolling composite method, diffusion welding method, explosive composite method, stir friction welding method, etc. Since rolling composite is a commonly used method for preparing and processing metal composite materials, it can achieve continuous and large-scale production of layered metal composite materials. Therefore, rolling composite method is preferred to prepare aluminum / magnesium / aluminum composite plates.

[0004] However, when preparing layered metal composites using the traditional rolling composite method, it is difficult to achieve sufficient interface bonding for dissimilar metals with large differences in mechanical properties, which can easily cause cracking at the bonding interface. As a result, the prepared layered metal composites are prone to defects such as holes and cracks at the interface, which seriously reduces the mechanical properties and forming properties of the layered metal composites. Summary of the invention

[0005] The purpose of the present invention is to provide a method for ultrasonically assisted differential temperature rolling of aluminum / magnesium / aluminum three-layer composite plates, which can enable dissimilar metals with large differences in plastic deformation capabilities to be fully combined and avoid the occurrence of defects such as holes and cracks at the interface of the prepared layered metal composite materials.

[0006] To achieve the above purpose, the specific technical scheme of the method for ultrasonic-assisted differential temperature rolling of aluminum / magnesium / aluminum three-layer composite plate provided by the present invention is as follows:

[0007] A method for ultrasonically assisted differential temperature rolling of aluminum / magnesium / aluminum three-layer composite plates, comprising the following steps:

[0008] The upper and lower surfaces of the magnesium plate are sequentially subjected to online grinding, alcohol cleaning and room temperature drying to obtain a pretreated magnesium plate, and at the same time, the surfaces to be bonded of the two aluminum strips are ground to remove the oxide film, alcohol cleaning, and room temperature drying to obtain two pretreated aluminum strips;

[0009] The pretreated magnesium plate is placed in an induction coil heating furnace for heating to obtain a heated magnesium plate, and the two pretreated aluminum strips are welded and edge-sealed to obtain two rolled aluminum strips;

[0010] Two rolled aluminum strips are placed on upper and lower unwinders respectively, and a heated magnesium plate is placed between the two rolled combined aluminum strips to obtain an aluminum / magnesium / aluminum three-layer plate;

[0011] Rolling the aluminum / magnesium / aluminum three-layer plate with rollers, and applying ultrasonic vibration to the upper and lower rollers to obtain the rolled aluminum / magnesium / aluminum three-layer plate;

[0012] The rolled aluminum / magnesium / aluminum three-layer plate is straightened and trimmed to obtain a finished aluminum / magnesium / aluminum three-layer composite plate.

[0013] The present invention is also characterized in that:

[0014] When the surface of the magnesium plate and the surfaces to be combined of the two aluminum strips are cleaned with alcohol, cotton yarn dipped in anhydrous ethanol is used to wipe the upper and lower surfaces of the magnesium plate and the surfaces to be combined and the sides of each aluminum strip 2 to 3 times, and then wipe them clean.

[0015] The thickness of the magnesium plate is 10 mm to 20 mm, and the thickness of each aluminum strip is 0.05 mm to 0.2 mm.

[0016] When the pretreated magnesium plate is placed in an induction coil heating furnace for heating, transverse magnetic induction heating is used for heating.

[0017] The heating temperature is 300°C to 550°C, and the heating time is 5min to 60min.

[0018] The reduction rate of the upper and lower rollers is 30% to 50%.

[0019] The vibration frequency of the ultrasonic device is 15kHz to 30kHz.

[0020] The method of ultrasonically assisted different temperature rolling of aluminum / magnesium / aluminum three-layer composite plate of the present invention has the following advantages:

[0021] First, the magnesium plate is heated by an induction coil heating furnace, while the aluminum strip is not heated, so that the magnesium plate and the aluminum plate can be rolled at different temperatures, which can reduce the plasticity difference caused by the performance difference between the two materials of magnesium and aluminum. At the same time, by applying ultrasonic waves on the rollers, the oxide layer of the to-be-bonded surface of the aluminum / magnesium / aluminum three-layer plate is broken, so that the dissimilar metals with large plasticity differences can be fully bonded, avoiding cracking at the interface after bonding, thereby avoiding the occurrence of defects such as holes and cracks in the composite interface of the prepared aluminum / magnesium / aluminum three-layer composite plate, thereby obtaining an aluminum / magnesium / aluminum three-layer composite plate with good interface metallurgical bonding and excellent performance, thereby improving the quality of the aluminum / magnesium / aluminum three-layer composite plate.

[0022] Second, heating the magnesium plate by an induction coil heating furnace can make the heating speed fast and efficient. Moreover, during heating, the coil of the induction coil heating furnace has no direct contact with the magnesium plate, which will not cause impurities to adhere to the surface of the magnesium plate during heating, further improving the quality of the aluminum / magnesium / aluminum three-layer composite plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the process flow of the present invention;

[0024] Figure 2 It is a schematic diagram of the structure of the rolling device in the present invention.

[0025] Reference numerals:

[0026] 1. Push rod; 2. Coil heating device; 3. Induction coil heating furnace; 4. Magnesium plate; 5. Insulation cover; 6. Uncoiler; 7. Aluminum strip; 8. Ultrasonic device; 9. Roller. DETAILED DESCRIPTION

[0027] The technical solution in the present application will be described clearly and in detail below in conjunction with the accompanying drawings. Among them, in the description of the embodiments of the present application, unless otherwise specified, " / " means or, for example, A / B can mean A or B: "and / or" in the text is only a description of the association relationship of associated objects, indicating that there can be three relationships, such as A and / or B, which can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, "multiple" refers to two or more than two. The following terms "first" and "second" are used for descriptive purposes only and cannot be understood as implying or suggesting relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features.

[0028] like Figure 1 As shown, the present invention provides a method for ultrasonically assisted differential temperature rolling of aluminum / magnesium / aluminum three-layer composite plates, comprising the following steps:

[0029] The upper and lower surfaces of the magnesium plate are sequentially subjected to online grinding, alcohol cleaning and room temperature drying to obtain a pretreated magnesium plate, and at the same time, the surfaces to be bonded of the two aluminum strips are ground to remove the oxide film, alcohol cleaning, and room temperature drying to obtain two pretreated aluminum strips;

[0030] The pretreated magnesium plate is placed in an induction coil heating furnace for heating to obtain a heated magnesium plate, and the two pretreated aluminum strips are welded and edge-sealed to obtain two rolled aluminum strips;

[0031] Two rolled aluminum strips are placed on upper and lower unwinders respectively, and a heated magnesium plate is placed between the two rolled combined aluminum strips to obtain an aluminum / magnesium / aluminum three-layer plate;

[0032] Rolling the aluminum / magnesium / aluminum three-layer plate with rollers, and applying ultrasonic vibration to the upper and lower rollers to obtain the rolled aluminum / magnesium / aluminum three-layer plate;

[0033] The rolled aluminum / magnesium / aluminum three-layer plate is straightened and trimmed to obtain a finished aluminum / magnesium / aluminum three-layer composite plate.

[0034] By adopting the above method, only the magnesium plate is heated by the induction coil heating furnace, and different temperature rolling can be achieved, which can reduce the plasticity difference caused by the performance difference between the two materials of magnesium and aluminum, and by applying ultrasonic waves on the rollers, the oxide layer on the surface of the metal to be combined is broken, thereby achieving full combination of the interface of dissimilar metals with large mechanical property differences, avoiding defects such as holes and cracks in the composite interface, and improving the interface bonding quality of the aluminum / magnesium / aluminum three-layer composite plate. At the same time, the heating speed is fast and the efficiency is high when using the induction coil heating furnace, and during the induction coil heating process, the coil and the magnesium plate are not in direct contact, which will not cause impurities to adhere to the surface of the magnesium plate during heating.

[0035] When the surface of the magnesium plate and the surfaces to be combined of the two aluminum strips are cleaned with alcohol, cotton yarn dipped in anhydrous ethanol is used to wipe the upper and lower surfaces of the magnesium plate and the surfaces to be combined and the sides of each aluminum strip 2 to 3 times, and then wipe them clean.

[0036] The thickness of magnesium plate is 10mm~20mm, and the thickness of each aluminum strip is 0.05mm~0.2mm. For magnesium plate, magnesium plate less than 10mm is thin, and it cannot withstand the rolling force during rolling and cracks are generated, which weakens the interface bonding force of the composite plate and leads to low overall strength of the composite plate. Magnesium plate greater than 20mm is too thick, and may cause local overheating and oxidation problems due to uneven temperature distribution during heating. Therefore, by controlling the thickness of magnesium plate within the range of 10mm~20mm, the magnesium plate can maintain sufficient strength, rigidity and plasticity, taking into account the mechanical properties of the material, rolling effect and production efficiency, which is conducive to plastic deformation and lamination during rolling. For aluminum strip, aluminum strip less than 0.05mm is too thin, and it is easy to break or wrinkle during rolling, increasing the defects of the composite plate. Aluminum strip greater than 0.2mm is too thick, and it is very easy to produce uneven stress distribution at the bonding interface, making it difficult to form a tight metallurgical bond with the magnesium plate, affecting the final composite effect. Therefore, by controlling the thickness of the aluminum strip within the range of 0.05mm to 0.2mm, it can fit tightly to the magnesium plate to form a strong composite structure, which is conducive to metallurgical bonding during the rolling process. At the same time, it can enable the aluminum strip to better receive and transmit ultrasonic energy, promote the interface diffusion and bonding between aluminum and magnesium, which is critical to ensuring the overall quality and performance of the aluminum / magnesium / aluminum three-layer composite plate.

[0037] When the pretreated magnesium plate is placed in the induction coil heating furnace for heating, the transverse magnetic induction heating method is used for heating. Induction heating transfers heat through three methods: heat conduction, heat convection, and heat radiation. Transverse magnetic induction heating can generate a relatively uniform induced current in the thickness direction of the magnesium plate, thereby making the temperature of the magnesium plate more uniform in the thickness direction. However, longitudinal magnetic induction heating is very likely to generate a strong induced current in the length direction of the magnesium plate, resulting in uneven temperature distribution in the length direction, which is not conducive to the rolling of the composite plate. In addition, the longitudinal magnetic induction heating method is less efficient, so the present invention adopts the transverse magnetic induction heating method.

[0038] Among them, the heating temperature is 300℃~550℃, and the heating time is 5min~60min. The determination of this heating temperature range is based on the physical properties and rolling process requirements of magnesium alloy. If the temperature is lower than 300℃, the plasticity of magnesium alloy will be reduced due to its close-packed hexagonal crystal structure with only one slip plane active at low temperature, which is easy to cause processing difficulties and edge crack defects. If the temperature exceeds 550℃, it may cause magnesium alloy overheating, resulting in excessive grain growth, reduced performance, and increased oxidation and burning, affecting the quality and performance of the finished product. As for the setting of heating time, it is to ensure the temperature consistency of magnesium alloy billet. Heating time of less than 5 minutes may cause uneven temperature inside the material, affecting the rolling quality; and heating time of more than 60 minutes may cause unnecessary consumption of energy and reduce production efficiency. Therefore, controlling the heating temperature of magnesium alloy to 300℃ to 550℃ and limiting the heating time to 5 to 60 minutes can ensure the plasticity and formability of the material during rolling, while reducing oxidation and improving the overall quality of the finished product.

[0039] Among them, the reduction rate of the upper and lower rollers is 30% to 50%, which can make the three layers of aluminum, magnesium and aluminum fully contact and generate sufficient pressure during the rolling process, promote the atomic diffusion and interface bonding between aluminum and magnesium, and thus form a strong composite material. If the reduction rate is too low, the contact pressure between the three layers of materials is insufficient, which may lead to loose bonding and affect the performance of the composite plate; if the reduction rate is too high, the material may be over-deformed and produce defects such as cracks.

[0040] Among them, the vibration frequency of the ultrasonic device is 15kHz~30kHz. Within this frequency range, the ultrasonic energy can be effectively transmitted to the interface of the aluminum / magnesium / aluminum three-layer composite plate. If the frequency is too low, the ultrasonic energy transmission is insufficient, and it is difficult to fully play the role of ultrasonic assistance; if the frequency is too high, it may cause excessive dispersion of energy and fail to concentrate at the interface, which is also not conducive to interface bonding. The frequency range of 15kHz-30kHz can produce a moderate cavitation effect. The formation and rupture of cavitation bubbles can produce local high temperature, high pressure and microjets, which help to remove oxide films and impurities at the interface and promote the wetting and bonding of metals. When the frequency is too low, the cavitation effect is weak and it is difficult to effectively remove impurities; when the frequency is too high, the cavitation effect is too strong and will cause damage to the material. Therefore, it is necessary to control the ultrasonic vibration frequency to 15kHz~30kHz.

[0041] like Figure 2As shown, the present invention provides an apparatus for ultrasonically assisted different-temperature rolling of aluminum / magnesium / aluminum three-layer composite plates, comprising an induction coil heating furnace 3, a coil heating device 2 is arranged in the induction coil heating furnace 3, a push rod 1 is arranged at the entrance of the induction coil heating furnace 3, and a heat preservation cover 5 is arranged horizontally of the induction coil heating furnace 3, the push rod 1 is used to push the magnesium plate 4 into the induction coil heating furnace, and after heating, the magnesium plate 4 is pushed out of the induction coil heating furnace 3 to enter the heat preservation cover 5, and two uncoilers 6 are arranged on the side of the heat preservation cover away from the coil heating device, and the two uncoilers 6 are arranged up and down, so as to facilitate placing two rolled combined aluminum strips 7 on the two uncoilers 6, and rollers 9 are respectively arranged near the two uncoilers 6, and each roller 9 is provided with an ultrasonic device 8, and the two rollers 9 are driven by the two ultrasonic devices 8 to perform ultrasonic vibration to realize the rolling of the aluminum / magnesium / aluminum three-layer plate.

[0042] like Figure 2 As shown, each ultrasonic vibration device includes an ultrasonic generator, which acts on the roller to apply ultrasonic waves to the roller.

[0043] Example 1

[0044] Select a magnesium plate with a size of 90mm*30mm*10mm and two aluminum strips with a width and thickness of 30mm and 0.1mm respectively;

[0045] The upper and lower surfaces of the magnesium plate are polished, cleaned with alcohol, and dried at room temperature in turn to obtain a pretreated magnesium plate. At the same time, the surfaces to be bonded of the two aluminum strips are polished to remove the oxide film, cleaned with alcohol, and dried at room temperature to obtain two pretreated aluminum strips.

[0046] The pretreated magnesium plate was placed in an induction coil heating furnace for heating at a temperature of 350°C for 40 minutes to obtain a heated magnesium plate, and the two pretreated aluminum strips were welded and edge-sealed to obtain two rolled combined aluminum strips;

[0047] Place two rolled aluminum strips on the upper and lower unwinders respectively, and push the heated magnesium plate into the heat preservation cover;

[0048] The aluminum / magnesium / aluminum three-layer slab is rolled by a roller, and an ultrasonic vibration frequency of 30 kHz is applied to the upper and lower rollers, and the rolling is performed under a reduction rate of 40% to obtain a rolled aluminum / magnesium / aluminum three-layer composite plate;

[0049] The rolled aluminum / magnesium / aluminum three-layer plate is straightened, trimmed, segmented and packaged to obtain a finished aluminum / magnesium / aluminum three-layer composite plate.

[0050] At the same time, a control example was set up, using the traditional rolling process as follows:

[0051] A magnesium plate with a size of 90 mm*30 mm*10 mm and two aluminum plates with a size of 90 mm*30 mm*0.1 mm are selected; the upper and lower surfaces of the magnesium plate are polished, cleaned with alcohol and dried at room temperature in turn to obtain a pretreated magnesium plate, and the surfaces to be combined of the two aluminum plates are polished to remove the oxide film, cleaned with alcohol and dried at room temperature; then the two aluminum plates are placed on the upper and lower surfaces of the magnesium plate respectively to make an aluminum / magnesium / aluminum three-layer slab; the prepared slab is placed in a tubular heating furnace for heating, the temperature is set to 350°C, and the time is set to 40 minutes; rolling is performed under a reduction rate of 40% to obtain a rolled aluminum / magnesium / aluminum three-layer composite plate; the rolled aluminum / magnesium / aluminum three-layer plate is straightened, trimmed, segmented and packaged to obtain a finished aluminum / magnesium / aluminum three-layer composite plate.

[0052] The specific data of mechanical properties of the finished aluminum / magnesium / aluminum three-layer composite plate obtained by the conventional rolling process and the ultrasonic-assisted different-temperature rolling process of the present invention are as follows:

[0053]

[0054] It can be seen from the table that the finished aluminum / magnesium / aluminum three-layer composite plate obtained by the ultrasonic-assisted differential temperature rolling process of the present invention is superior to the traditional rolling process in terms of tensile strength, yield strength and elongation at break.

[0055] Example 2

[0056] Select a magnesium plate with a size of 100mm*40mm*15mm and two aluminum strips with a width and thickness of 40mm and 0.15mm respectively.

[0057] The upper and lower surfaces of the magnesium plate are polished, cleaned with acetone and dried at room temperature in turn to obtain a pretreated magnesium plate. At the same time, the surfaces to be bonded of the two aluminum strips are polished to remove the oxide film, cleaned with acetone and dried at room temperature to obtain two pretreated aluminum strips.

[0058] The pretreated magnesium plate was placed in an induction coil heating furnace for heating at a temperature of 400°C for 20 minutes to obtain a heated magnesium plate. The two pretreated aluminum strips were welded and edge-sealed to obtain two rolled combined aluminum strips.

[0059] Two rolled aluminum strips are placed on the upper and lower unwinders respectively, and the heated magnesium plate is pushed into the heat preservation cover.

[0060] The aluminum / magnesium / aluminum three-layer slab is rolled by using rollers, and an ultrasonic vibration frequency of 25kHz is applied to the upper and lower rollers. The rolling is performed under a reduction rate of 35% to obtain a rolled aluminum / magnesium / aluminum three-layer composite plate.

[0061] The rolled aluminum / magnesium / aluminum three-layer plate is straightened, trimmed, segmented and packaged to obtain a finished aluminum / magnesium / aluminum three-layer composite plate.

[0062] At the same time, a control example was set up, using the traditional rolling process as follows:

[0063] Select a magnesium plate with a size of 100mm*40mm*15mm, and select two aluminum plates with a size of 100mm*40mm*0.15mm. The upper and lower surfaces of the magnesium plate are polished, cleaned with acetone and dried at room temperature in turn to obtain a pretreated magnesium plate. At the same time, the surfaces to be combined of the two aluminum plates are polished to remove the oxide film, cleaned with acetone, and dried at room temperature. Then the two aluminum plates are placed on the upper and lower surfaces of the magnesium plate, respectively, and stacked in the order of aluminum-magnesium-aluminum to make an aluminum / magnesium / aluminum slab. The prepared slab is placed in a tubular heating furnace for heating, the temperature is set to 400℃, and the time is set to 20min. Rolling is carried out under a reduction rate of 35% to obtain a rolled aluminum / magnesium / aluminum three-layer composite plate. After straightening, trimming, segmenting, and packaging the rolled aluminum / magnesium / aluminum three-layer plate, a finished aluminum / magnesium / aluminum three-layer composite plate is obtained.

[0064] The specific data of mechanical properties of the finished aluminum / magnesium / aluminum three-layer composite plate obtained by the conventional rolling process and the ultrasonic-assisted different-temperature rolling process of the present invention are as follows:

[0065]

[0066] It can be seen from the table that the finished aluminum / magnesium / aluminum three-layer composite plate obtained by the ultrasonic-assisted differential temperature rolling process of the present invention is superior to the traditional rolling process in terms of tensile strength, yield strength and elongation at break.

[0067] The present invention heats the magnesium plate by an induction coil heating furnace, which has the following advantages:

[0068] 1. Efficient and fast

[0069] Induction heating uses the principle of electromagnetic induction to generate eddy currents in the magnesium plate itself to generate heat. The heat is directly generated inside the magnesium plate, and the heating speed is extremely fast. Compared with traditional heating methods, it can greatly shorten the heating time and improve production efficiency.

[0070] 2. Precise temperature control

[0071] The induction coil heating furnace can achieve precise control of the heating temperature of the magnesium plate by precisely controlling the output power and frequency of the power supply. This is very important for the processing of magnesium plates because magnesium has a low melting point and is more sensitive to temperature changes. Accurate temperature control can ensure that the magnesium plate will not overheat or have uneven temperatures during the heating process, thereby ensuring product quality.

[0072] 3. Energy saving and environmental protection

[0073] Energy saving: Induction heating has high efficiency and low energy loss. Since the heat is directly generated inside the magnesium plate, there is no need to heat the surrounding air or medium first and then transfer the heat to the magnesium plate by heat conduction like the traditional heating method, which can greatly reduce energy waste.

[0074] Environmental protection: There is no open flame, no smoke, no exhaust gas emission during the induction heating process, which is environmentally friendly. Under the current situation of increasingly stringent environmental protection requirements, induction coil heating furnaces are in line with the development trend of green production.

[0075] 4. Uniform heating

[0076] The magnetic field generated by the induction coil can be evenly distributed around the magnesium plate, so that all parts of the magnesium plate are heated at the same time, thereby achieving uniform heating, which can make the structure of the magnesium plate more uniform, improve its mechanical properties and corrosion resistance, which is crucial to ensure the performance and quality of the magnesium plate. Uneven heating may cause defects such as deformation and cracks in the magnesium plate, and the induction coil heating furnace can effectively avoid these problems.

[0077] 5. Easy to operate

[0078] Induction coil heating furnaces usually use an automated control system, which is easy to operate. You only need to set the heating parameters to achieve automatic heating. This not only reduces the labor intensity of operators, but also reduces the impact of human factors on the heating process, and improves the stability and reliability of heating. At the same time, the automated control system can also monitor the temperature, power and other parameters during the heating process in real time, which is convenient for timely adjustment and optimization of the heating process.

[0079] 6. Strong adaptability

[0080] The induction coil heating furnace can be customized according to different specifications and shapes of magnesium plates, and has strong adaptability. Whether it is a thin plate, a thick plate or a special-shaped plate, it can be effectively heated by adjusting the shape and layout of the induction coil. In addition, the induction coil heating furnace can also be linked with other production equipment to achieve integration of automated production lines.

[0081] The invention has the following advantages by using ultrasound-assisted different-temperature rolling of aluminum / magnesium / aluminum three-layer composite plates:

[0082] 1. Improve bonding performance

[0083] The role of ultrasound: Ultrasonic assistance is introduced during the rolling process. The high-frequency vibration of ultrasound can break the oxide film and impurities on the metal surface, promote the atomic diffusion and bonding between the aluminum and magnesium layers, and thus significantly improve the interface bonding strength of the composite plate.

[0084] Advantages of different temperature rolling: Reasonable control of the temperature of each layer can make the aluminum layer and the magnesium layer in the best deformation state during the rolling process, further enhancing the interface bonding. Only the magnesium layer is heated to a higher temperature to improve its plasticity, while the aluminum layer is kept at a relatively low temperature to ensure strength, which can ensure good bonding and take into account the overall performance of the composite plate.

[0085] 2. Improve mechanical properties

[0086] Material strengthening: The synergistic effect of ultrasonic assistance and differential temperature rolling can make the microstructure of the composite plate more refined and uniform, thereby improving its mechanical properties.

[0087] Anisotropy improvement: By optimizing the rolling process parameters, the difference in mechanical properties of the composite plate in different directions can be reduced and its anisotropy can be improved.

[0088] 3. Optimize processing performance

[0089] Improved plasticity: Different temperature rolling can adjust the temperature according to the characteristics of different metal layers, so that the composite plate has better plastic deformation ability during the rolling process. This helps to reduce cracks and defects during the rolling process and improve the yield rate. At the same time, ultrasonic assistance can further improve the fluidity of the metal, making it easier to process the composite plate into various complex shapes.

[0090] Reduce processing difficulty: Since the mechanical properties of the composite plate are improved, lower processing force and simpler process can be used in subsequent processing, such as stamping and bending, to reduce processing costs.

[0091] It is to be understood that the present invention is described by some embodiments, and it is known to those skilled in the art that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the scope of protection of the present invention.

Claims

1. A method for ultrasonically assisted temperature-differential rolling of aluminum / magnesium / aluminum three-layer composite plates, characterized in that: The following steps are involved: The upper and lower surfaces of the magnesium plate are sequentially online polished, alcohol cleaned and dried at room temperature to obtain a pretreated magnesium plate, and at the same time, the surfaces to be bonded of the two aluminum strips are polished to remove the oxide film, alcohol cleaned and dried at room temperature to obtain two pretreated aluminum strips; The pretreated magnesium plate is placed in an induction coil heating furnace for heating to obtain a heated magnesium plate, and the two pretreated aluminum strips are welded and edge-sealed to obtain two rolled aluminum strips; Two rolled aluminum strips are placed on upper and lower unwinders respectively, and a heated magnesium plate is placed between the two rolled combined aluminum strips to obtain an aluminum / magnesium / aluminum three-layer plate; Rolling the aluminum / magnesium / aluminum three-layer plate with rollers, and applying ultrasonic vibration to the upper and lower rollers to obtain the rolled aluminum / magnesium / aluminum three-layer plate; The rolled aluminum / magnesium / aluminum three-layer plate is straightened and trimmed to obtain a finished aluminum / magnesium / aluminum three-layer composite plate.

2. The method for ultrasonically assisted differential temperature rolling of aluminum / magnesium / aluminum three-layer composite plates according to claim 1, characterized in that: When the surface of the magnesium plate and the surfaces to be combined of the two aluminum strips are cleaned with alcohol, use cotton yarn dipped in anhydrous ethanol to wipe the upper and lower surfaces of the magnesium plate and the surfaces to be combined and the sides of each aluminum strip 2 to 3 times, and then wipe them clean.

3. The method for ultrasonically assisted differential temperature rolling of aluminum / magnesium / aluminum three-layer composite plates according to claim 1, characterized in that: The thickness of the magnesium plate is 10 mm to 20 mm, and the thickness of each aluminum strip is 0.05 mm to 0.2 mm.

4. The method for ultrasonically assisted differential temperature rolling of aluminum / magnesium / aluminum three-layer composite plates according to claim 1, characterized in that: When the pretreated magnesium plate is placed in an induction coil heating furnace for heating, transverse magnetic induction heating is used for heating.

5. The method for ultrasonically assisted differential temperature rolling of aluminum / magnesium / aluminum three-layer composite plates according to claim 4, characterized in that: The heating temperature is 300° C. to 550° C., and the heating time is 5 min to 60 min.

6. The method for ultrasonically assisted differential temperature rolling of aluminum / magnesium / aluminum three-layer composite plates according to claim 1, characterized in that: The reduction rate of the upper and lower rollers is 30% to 50%.

7. The method for ultrasonically assisted differential temperature rolling of aluminum / magnesium / aluminum three-layer composite plates according to claim 1, characterized in that: The vibration frequency of the ultrasonic device is 15kHz to 30kHz.

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