A method for ultrasonically assisted differential temperature rolling of aluminum / magnesium / aluminum three-layer composite plates

Abstract

The present invention belongs to the technical field of metal composite material preparation, and relates to a method for ultrasonically assisted differential temperature rolling of an aluminum / magnesium / aluminum three-layer composite plate, comprising the following steps: pre-treating a magnesium plate and two pre-treated aluminum strips; heating the heat-treated magnesium plate in an induction coil heating furnace, welding and sealing the edges of the heat-treated magnesium plate to obtain two rolled composite aluminum strips; preparing an aluminum / magnesium / aluminum three-layer plate blank; applying ultrasonic waves to rollers, and rolling the aluminum / magnesium / aluminum three-layer plate blank using upper and lower rollers to obtain an aluminum / magnesium / aluminum three-layer composite plate. The present invention heats the magnesium plate by an induction coil while not heating the aluminum strip, thereby achieving differential temperature rolling between the magnesium plate and the aluminum plate, which can reduce the plasticity difference between the magnesium and aluminum materials caused by the performance difference between the two materials. Moreover, by applying ultrasonic waves to the rollers, the oxide layer on the surface of the metal to be bonded is broken, thereby achieving full bonding of dissimilar metals with large plasticity differences, and avoiding defects such as holes and cracks at the composite interface of the aluminum / magnesium / aluminum three-layer composite plate.

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. It has a series of advantages such as low density, high specific strength, and radiation resistance. However, 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 make 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] Currently, methods for preparing metal composite plates include extrusion bonding, rolling bonding, diffusion welding, explosive bonding, and friction stir welding. Rolling bonding is a commonly used method for preparing and processing metal composite materials, enabling continuous, large-scale production of layered metal composites. Therefore, rolling bonding is the preferred method for preparing aluminum / magnesium / aluminum composite plates.

[0004] However, when preparing layered metal composite materials 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 composite materials are prone to defects such as holes and cracks at the interface, which seriously reduces the mechanical properties and forming performance of the layered metal composite materials. 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 fully combine dissimilar metals with large differences in plastic deformation capabilities 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 objectives, the present invention provides a method for ultrasonically assisted differential temperature rolling of aluminum / magnesium / aluminum three-layer composite plates, the specific technical solution of which is as follows:

[0007] A method for ultrasonically assisted differential temperature rolling of an aluminum / magnesium / aluminum three-layer composite plate comprises 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. 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 heat-treated 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 uncoilers respectively, and the heated magnesium plate is placed between the two rolled combined aluminum strips to obtain an aluminum / magnesium / aluminum three-layer plate;

[0011] Rolling an aluminum / magnesium / aluminum three-layer plate using rollers and applying ultrasonic vibration to the upper and lower rollers to obtain a 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 bonded 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 bonded and the sides of each aluminum strip 2 to 3 times, and then wipe them clean.

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

[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 5 min to 60 min.

[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 ultrasonic-assisted differential temperature rolling method for aluminum / magnesium / aluminum three-layer composite plates 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 different temperature rolling can be achieved between the magnesium plate and the aluminum plate, which can reduce the plasticity difference between the two materials of magnesium and aluminum caused by the performance difference. At the same time, by applying ultrasonic waves on the rolling 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 are fully bonded, avoiding cracking at the interface after bonding, thereby avoiding the occurrence of defects such as holes and cracks at 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] Secondly, 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 structural schematic diagram 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 solutions in this application will be described clearly and in detail below in conjunction with the accompanying drawings. In the description of the embodiments of this 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 this 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. 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 heat-treated 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 uncoilers respectively, and the heated magnesium plate is placed between the two rolled combined aluminum strips to obtain an aluminum / magnesium / aluminum three-layer plate;

[0032] Rolling an aluminum / magnesium / aluminum three-layer plate using rollers and applying ultrasonic vibration to the upper and lower rollers to obtain a 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] Using the above method, only the magnesium plate is heated in an induction coil heating furnace, which enables differential temperature rolling. This can reduce the plasticity difference between the magnesium and aluminum materials caused by the performance differences. By applying ultrasonic waves to the rollers, the oxide layer on the surface of the metal to be bonded is broken, thereby achieving full bonding of the interface of dissimilar metals with large differences in mechanical properties, avoiding defects such as holes and cracks in the composite interface, and improving the interfacial bonding quality of the aluminum / magnesium / aluminum three-layer composite plate. At the same time, the use of an induction coil heating furnace has a fast heating speed and high efficiency. Moreover, during the induction coil heating process, the coil and the magnesium plate do not directly contact each other, which prevents impurities from adhering to the surface of the magnesium plate during heating.

[0035] Among them, when the surface of the magnesium plate and the surfaces to be bonded 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 bonded and the sides of each aluminum strip 2 to 3 times, and then wipe them clean.

[0036] The thickness of the magnesium sheet ranges from 10mm to 20mm, and the thickness of each aluminum strip ranges from 0.05mm to 0.2mm. For magnesium sheet, sheets less than 10mm are too thin and cannot withstand the rolling force during rolling, resulting in cracks. This weakens the interfacial bonding strength of the composite sheet, resulting in lower overall strength. Magnesium sheet greater than 20mm is too thick and may experience localized overheating and oxidation during heating due to uneven temperature distribution. Therefore, by controlling the thickness of the magnesium sheet within the range of 10mm to 20mm, the magnesium sheet can maintain sufficient strength, rigidity, and plasticity, taking into account the material's mechanical properties, rolling performance, and production efficiency, and facilitating plastic deformation and lamination during rolling. For aluminum strip, sheets less than 0.05mm are too thin and are prone to breakage or wrinkling during rolling, increasing defects in the composite sheet. Aluminum strips greater than 0.2mm are too thick and easily produce uneven stress distribution at the bonding interface, making it difficult to form a close metallurgical bond with the magnesium sheet, 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 very critical to ensuring the overall quality and performance of the aluminum / magnesium / aluminum three-layer composite plate.

[0037] When the pretreated magnesium sheet is placed in an induction coil heating furnace for heating, transverse magnetic induction heating is used. 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 through the thickness of the magnesium sheet, thereby making the temperature of the magnesium sheet more uniform throughout the thickness. However, longitudinal magnetic induction heating is likely to generate a strong induced current along the length of the magnesium sheet, resulting in an uneven temperature distribution along the length, which is not conducive to the rolling of the composite sheet. In addition, longitudinal magnetic induction heating is relatively inefficient. Therefore, the present invention adopts transverse magnetic induction heating.

[0038] Among them, the heating temperature is 300℃~550℃, and the heating time is 5min~60min. This heating temperature range is determined taking into account the physical properties of magnesium alloy and the rolling process requirements. 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 active slip plane at low temperature, which can easily cause processing difficulties and edge crack defects. If the temperature exceeds 550℃, it may cause the magnesium alloy to overheat, 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; heating time of more than 60 minutes may cause unnecessary energy consumption and reduce production efficiency. Therefore, controlling the heating temperature of magnesium alloy between 300℃ and 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] The reduction ratio of the upper and lower rollers is 30% to 50%, which ensures full contact and sufficient pressure between the aluminum, magnesium, and aluminum layers during rolling, promoting atomic diffusion and interfacial bonding between the aluminum and magnesium, thereby forming a strong composite material. If the reduction ratio is too low, the contact pressure between the three layers will be insufficient, resulting in a loose bond and affecting the performance of the composite plate. If the reduction ratio is too high, the material may be excessively deformed, resulting in defects such as cracks.

[0040] Among them, the vibration frequency of the ultrasonic device is 15kHz~30kHz. Within this frequency range, 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 a device 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 being provided in the induction coil heating furnace 3, a push rod 1 being provided at the entrance of the induction coil heating furnace 3, and a heat preservation cover 5 being provided horizontally of the induction coil heating furnace 3, the push rod 1 being used to push the magnesium plate 4 into the induction coil heating furnace, and after heating is completed, the magnesium plate 4 is pushed out of the induction coil heating furnace 3 so that it enters the heat preservation cover 5, and two uncoilers 6 are provided on the side of the heat preservation cover away from the coil heating device, and the two uncoilers 6 are arranged up and down to facilitate placing two rolled combined aluminum strips 7 on the two uncoilers 6, and rollers 9 are respectively provided near the two uncoilers 6, and each roller 9 is provided with an ultrasonic device 8, and the two ultrasonic devices 8 drive the two rollers 9 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 of 30mm and a thickness of 0.1mm respectively;

[0045] The upper and lower surfaces of the magnesium plate are polished, cleaned with alcohol, and dried at room temperature in sequence 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 350°C for 40 minutes to obtain a heated magnesium plate. The two pretreated aluminum strips were welded and edge-sealed to obtain two rolled composite aluminum strips.

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

[0048] The aluminum / magnesium / aluminum three-layer slab was rolled using rollers, and an ultrasonic vibration frequency of 30 kHz was applied to the upper and lower rollers. The rolling was carried out at 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 90mm*30mm*10mm and two aluminum plates with a size of 90mm*30mm*0.1mm are selected; the upper and lower surfaces of the magnesium plate are polished, cleaned with alcohol and dried at room temperature in sequence 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; the two aluminum plates are then 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; it is rolled 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 on the mechanical properties of the finished aluminum / magnesium / aluminum three-layer composite plates obtained by the conventional rolling process and the ultrasonic-assisted differential temperature rolling process of the present invention are as follows:

[0053]

[0054] As can be seen from the table, 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 were polished, cleaned with acetone, and dried at room temperature to obtain a pretreated magnesium plate. At the same time, the surfaces of the two aluminum strips to be bonded were polished to remove the oxide film, cleaned with acetone, and dried at room temperature to obtain two pretreated aluminum strips.

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

[0059] Place the two rolled aluminum strips on the upper and lower uncoilers respectively, and push the heated magnesium plate into the insulation cover.

[0060] The aluminum / magnesium / aluminum three-layer slab was rolled using rollers, and an ultrasonic vibration frequency of 25kHz was applied to the upper and lower rollers. The rolling was carried out at 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] A magnesium plate measuring 100mm*40mm*15mm and two aluminum plates, each measuring 100mm*40mm*0.15mm, were selected. The upper and lower surfaces of the magnesium plate were polished, cleaned with acetone, and dried at room temperature to produce a pretreated magnesium plate. Simultaneously, the surfaces of the two aluminum plates to be bonded were polished to remove the oxide film, cleaned with acetone, and dried at room temperature. The two aluminum plates were then placed on the upper and lower surfaces of the magnesium plate, stacked in the order of aluminum-magnesium-aluminum, to produce an aluminum / magnesium / aluminum slab. The prepared slabs were heated in a tubular furnace at 400°C for 20 minutes. Rolling was performed at a reduction of 35% to produce a rolled aluminum / magnesium / aluminum three-layer composite plate. The rolled aluminum / magnesium / aluminum three-layer plate was then straightened, trimmed, segmented, and packaged to produce the finished aluminum / magnesium / aluminum three-layer composite plate.

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

[0065]

[0066] As can be seen from the table, 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 has the following advantages when heating the magnesium plate by an induction coil heating furnace:

[0068] 1. Efficient and fast

[0069] Induction heating uses the principle of electromagnetic induction to generate eddy currents within the magnesium sheet, generating heat. Heat is generated directly within the magnesium sheet, resulting in an extremely rapid temperature rise. Compared to traditional heating methods, it can significantly shorten heating time and improve production efficiency.

[0070] 2. Precise temperature control

[0071] Induction coil furnaces enable precise control of the magnesium sheet heating temperature by precisely controlling the power output and frequency of the power supply. This is crucial for magnesium sheet processing, as magnesium has a low melting point and is sensitive to temperature fluctuations. Accurate temperature control prevents overheating and uneven temperatures during heating, thus ensuring product quality.

[0072] 3. Energy saving and environmental protection

[0073] Energy saving: Induction heating is highly efficient and has minimal energy loss. Since heat is generated directly 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 through heat conduction as in traditional heating methods. This can significantly reduce energy waste.

[0074] Environmental protection: The induction heating process has no open flame, no smoke, and no exhaust gas emissions, which is environmentally friendly. In the current situation where environmental protection requirements are becoming increasingly stringent, 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, causing all parts of the magnesium plate to be heated simultaneously, thus achieving uniform heating. This can make the magnesium plate's structure more uniform, improve its mechanical properties and corrosion resistance, which is crucial to ensuring the performance and quality of the magnesium plate. Uneven heating may cause defects such as deformation and cracks in the magnesium plate, but induction coil heating furnaces can effectively avoid these problems.

[0077] 5. Easy to operate

[0078] Induction coil heating furnaces typically utilize automated control systems, offering easy operation. Simply set the heating parameters for automatic heating. This not only reduces operator workload but also mitigates the impact of human factors on the heating process, improving heating stability and reliability. Furthermore, automated control systems can monitor parameters such as temperature and power in real time during the heating process, facilitating timely adjustment and optimization of the heating process.

[0079] 6. Strong adaptability

[0080] Induction coil heating furnaces can be customized to accommodate magnesium sheet sizes and shapes, offering a wide range of adaptability. Whether thin, thick, or even irregularly shaped, efficient heating can be achieved by adjusting the shape and layout of the induction coils. Furthermore, induction coil heating furnaces can be integrated with other production equipment to achieve automated production line integration.

[0081] The present invention has the following advantages:

[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 differential temperature rolling: Properly controlling the temperature of each layer allows the aluminum and magnesium layers to maintain optimal deformation during rolling, further enhancing interfacial bonding. Heating only the magnesium layer to a higher temperature to improve its plasticity, while maintaining the aluminum layer at a relatively lower temperature to ensure strength, ensures a good bond while also maintaining 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: Differential rolling allows the temperature to be adjusted according to the characteristics of the different metal layers, resulting in a composite plate with improved plastic deformation during the rolling process. This helps reduce cracks and defects during rolling and improves yield. Furthermore, ultrasonic assistance can further improve the metal's fluidity, making it easier to process the composite plate into various complex shapes.

[0090] Reduced processing difficulty: Due to the improved mechanical properties of the composite board, lower processing force and simpler process can be used in subsequent processing, such as stamping and bending, thereby reducing processing costs.

[0091] It will be understood that the present invention is described by way of some embodiments, and it will be appreciated by 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 to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are intended to be protected by the present invention.

Claims

1. A method for ultrasonically assisted differential temperature 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 subjected to online grinding, alcohol cleaning and room temperature drying to obtain a pretreated magnesium plate. 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. The pretreated magnesium plate is placed in an induction coil heating furnace for heating to obtain a heat-treated 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 uncoilers respectively, and the heated magnesium plate is placed between the two rolled combined aluminum strips to obtain an aluminum / magnesium / aluminum three-layer plate; Rolling an aluminum / magnesium / aluminum three-layer plate using rollers and applying ultrasonic vibration to the upper and lower rollers to obtain a 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; 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; The heating temperature is 300°C to 550°C, and the heating time is 5min to 60min; The vibration frequency of the ultrasonic device is 15kHz~30kHz.

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 cleaning the surface of the magnesium plate and the surfaces to be bonded of the two aluminum strips 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 bonded 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: When the pretreated magnesium plate is placed in an induction coil heating furnace for heating, transverse magnetic induction heating is used for heating.

4. 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%~50%.

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