Magnesium-aluminum composite foil and preparation method and application thereof
Magnesium-aluminum composite foil was prepared by pulsed current heating and multi-pass annealing, which solved the problems of interface oxidation and edge cracking in the rolling process of magnesium-aluminum composite foil, and realized the preparation of high-performance magnesium-aluminum composite foil, which is suitable for applications such as audio diaphragms, magnesium batteries and electromagnetic shielding.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-24
- Publication Date
- 2026-04-07
AI Technical Summary
Magnesium-aluminum composite foils suffer from problems such as interface oxidation defects, interface delamination, edge cracks, and strip breaks during the rolling process, leading to overall material failure. Furthermore, magnesium alloys have poor plastic deformation capabilities and high processing costs, which limit their application.
Magnesium-aluminum composite foil was prepared by heating pretreated magnesium and aluminum plates with pulsed current, and then by single-pass rolling and multi-pass annealing combined with cold rolling. The residual stress and texture during the rolling process were controlled to improve the interfacial bonding performance.
It achieves good interfacial bonding of magnesium-aluminum composite foil, reduces the deformation resistance of magnesium alloy, and has lightweight, corrosion resistance, good damping and electromagnetic shielding properties, making it suitable for applications such as audio diaphragms, magnesium batteries and electromagnetic shielding.
Smart Images
Figure CN121802138A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of magnesium-aluminum composite materials technology, and more specifically, to a magnesium-aluminum composite foil, its preparation method, and its application. Background Technology
[0002] Magnesium alloys possess advantages such as low density, high specific strength, and good vibration damping properties, making them widely used in the automotive and aerospace industries. However, their poor plastic deformation capacity, high processing costs, and poor corrosion resistance limit their further applications. Aluminum alloys are lightweight, have good plasticity, and strong corrosion resistance; moreover, aluminum is the most abundant metallic element in the Earth's crust, making it a readily available resource. Magnesium-aluminum layered composite materials combine the advantages of both magnesium and aluminum, showing broad application prospects in the defense industry and microelectronics.
[0003] The main methods for preparing metal composite foils and strips include spray deposition, diffusion welding, magnetron sputtering, and rolling composite methods. Among these, rolling composite methods are simple and low-cost, and are widely used in the preparation of layered metal composite materials. However, due to the different crystal structures of magnesium and aluminum, and the fact that magnesium is a close-packed hexagonal crystal, magnesium tends to form a strong basal texture during continuous rolling, resulting in strong anisotropy in multi-pass rolling processes. This leads to defects such as edge cracks and strip breaks during foil and strip rolling. In addition, the sliding friction resistance of the rolls during the shear deformation of magnesium plates causes uneven distribution of residual stress in the rolled magnesium plates, easily resulting in defects such as plate waviness. In the rolling process of magnesium / aluminum composite foils, interfacial bonding is particularly important; if defects such as interfacial oxidation exist during the rolling process of plates and strips, it will lead to interfacial delamination in subsequent foil rolling processes, causing the material to fail as a whole.
[0004] In view of this, the present invention is proposed. Summary of the Invention
[0005] The purpose of this invention is to provide a magnesium-aluminum composite foil, its preparation method, and its application, so as to solve or improve the above-mentioned technical problems.
[0006] This invention can be implemented as follows: In a first aspect, the present invention provides a method for preparing magnesium-aluminum composite foil, comprising the following steps: The original magnesium plate and the original aluminum plate were pre-annealed and the surface oxide layer was removed to obtain pre-treated magnesium plate and pre-treated aluminum plate. Pretreated magnesium plate and pretreated aluminum plate were heated by pulsed current to obtain hot magnesium plate and hot aluminum plate; A magnesium-aluminum composite plate is obtained by single-pass rolling of hot magnesium plate and hot aluminum plate; Magnesium-aluminum composite sheet is subjected to first annealing, straightening, multi-pass rolling and intermediate annealing to obtain magnesium-aluminum composite strip; Magnesium-aluminum composite strip is subjected to a second annealing and cold rolling to obtain magnesium-aluminum composite foil.
[0007] In an optional embodiment, both the original magnesium plate and the original aluminum plate are pre-annealed at 250°C to 350°C for 1 to 3 hours.
[0008] In an optional embodiment, the pulse current density corresponding to the pretreated magnesium plate is 100 A / mm². 2 ~150A / mm 2 The pulse current density corresponding to the pretreated aluminum plate is 60A / mm². 2 ~100A / mm 2 The surface temperature of the hot aluminum plate is 300℃~350℃.
[0009] In an optional embodiment, the preparation of the magnesium-aluminum composite plate includes at least one of the following features: Feature 1: The reduction in a single rolling pass is 40%~50%; Feature 2: The rolling tension during single-pass rolling is 45N~55N; Feature 3: After a single rolling pass, the surface temperature of the magnesium-aluminum composite plate is 160℃~180℃; Feature 4: The thickness of the magnesium-aluminum composite plate is 1mm~2.5mm.
[0010] In an optional embodiment, the preparation of the magnesium-aluminum composite strip includes at least one of the following features: Feature 5: The first annealing is carried out at 280℃~320℃ for 1h~3h; Feature 6: In multi-pass rolling, the reduction per pass is 10%~15%; Feature 7: The rolling tension during multi-pass rolling is 18N~22N; Feature 8: The intermediate annealing is performed 3 to 5 times, and each intermediate annealing is held at 280℃ to 320℃ for 0.5h to 1h; Feature 9: The thickness of the magnesium-aluminum composite strip is 0.5mm~0.8mm; Feature 10: The flatness of the magnesium-aluminum composite strip does not exceed 0.2 mm / m.
[0011] In an optional embodiment, the preparation of the magnesium-aluminum composite foil includes at least one of the following features: Feature 11: The second annealing is carried out at 180℃~220℃ for 0.5h~1h; Feature 12: The rolling tension during the cold rolling process is 4N~6N; Feature 13: The reduction in cold rolling is 5%~10%; Feature 14: The thickness of the magnesium-aluminum composite foil is 0.05mm~0.15mm; Feature 15: The flatness of the magnesium-aluminum composite foil does not exceed 5μm / m.
[0012] Secondly, the present invention provides a magnesium-aluminum composite foil, which is prepared by any of the preparation methods described in the foregoing embodiments.
[0013] In an optional embodiment, the ratio of the thickness of the original aluminum plate to the thickness of the original magnesium plate in the magnesium-aluminum composite foil is 0.25:(0.5~1).
[0014] In an optional embodiment, the magnesium-aluminum composite foil has at least one of the following characteristics: Feature 16: The density of magnesium-aluminum composite foil is ≤2.5 g / cm³. 3 ; Feature 17: When the damping of the magnesium-aluminum composite foil is 0.1, Q -1 Value ≥ 0.01; Feature 18: The electromagnetic shielding effectiveness of magnesium-aluminum composite foil is 75dB~100dB in the range of 0MHz~2000MHz; Feature 19: The tensile strength of magnesium-aluminum composite foil is 250MPa~320MPa; Feature 20: The elongation of the magnesium-aluminum composite foil is 3%~5%.
[0015] Thirdly, the present invention provides an application of the magnesium-aluminum composite foil as described in any of the foregoing embodiments, wherein the magnesium-aluminum composite foil is used in audio diaphragms, magnesium batteries or electromagnetic shielding products.
[0016] The beneficial effects of this invention include: In the preparation of magnesium-aluminum composite foil, this invention employs pulsed current to heat pretreated magnesium and aluminum plates separately, resulting in hot magnesium and hot aluminum plates. The pulsed current serves as the heat source during the composite plate rolling process, providing rapid heating. The rapid electron flow also helps reduce the formation of magnesium texture during rolling, lowering residual stress in the composite plate and facilitating subsequent deformation. By introducing pulsed current, this invention effectively achieves coordinated deformation during the magnesium and aluminum composite rolling process, reducing the deformation resistance of the magnesium alloy. The resulting magnesium-aluminum composite foil exhibits excellent interfacial bonding properties and plate shape. Furthermore, it possesses lightweight, corrosion resistance, and excellent damping, electromagnetic shielding, and high energy density properties, making it widely applicable in fields such as audio diaphragms, magnesium batteries, and electromagnetic shielding. Attached Figure Description
[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.
[0018] Figure 1 This is a SEM image of the interface of the magnesium-aluminum composite foil prepared in Example 2 of the present invention; Figure 2 This is an EBSD microstructure of the magnesium-aluminum composite foil prepared in Example 2 of the present invention; Figure 3 The tensile curves of the magnesium-aluminum composite strip and magnesium-aluminum composite foil prepared in Example 2 of the present invention are shown. Detailed Implementation
[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.
[0020] The magnesium-aluminum composite foil provided by this invention, its preparation method, and its application are described in detail below.
[0021] This invention provides a method for preparing magnesium-aluminum composite foil, comprising the following steps: S1: The original magnesium plate and the original aluminum plate are pre-annealed and the surface oxide layer is removed to obtain pre-treated magnesium plate and pre-treated aluminum plate.
[0022] In some alternative embodiments, the original magnesium plate may be pre-annealed at 250°C to 350°C (e.g., 250°C, 280°C, 300°C, 320°C or 350°C, etc.) for 1 hour to 3 hours (e.g., 1 hour, 2 hours or 3 hours, etc.).
[0023] The original aluminum sheet can also be pre-annealed at 250℃~350℃ (such as 250℃, 280℃, 300℃, 320℃ or 350℃, etc.) for 1h~3h (such as 1h, 2h or 3h, etc.).
[0024] Pre-annealing the raw magnesium and aluminum plates softens them, facilitating subsequent rolling processes. Furthermore, it removes the oxide layer from the surfaces of the magnesium and aluminum plates after pre-annealing, promoting better interfacial bonding between them.
[0025] In some alternative implementations, the original aluminum plate can be a pure aluminum plate, and the original magnesium plate can be a Mg-Li plate or a pure magnesium plate, etc.
[0026] S2: The pretreated magnesium plate and the pretreated aluminum plate are heated by pulsed current to obtain hot magnesium plate and hot aluminum plate.
[0027] Pulsed current serves as the heat source during the composite plate rolling process, providing rapid heating. The rapid electron flow also helps reduce the formation of magnesium texture during rolling, lowering residual stress in the composite plate and facilitating subsequent deformation. This invention, by introducing pulsed current, effectively achieves coordinated deformation during the magnesium and aluminum composite rolling process, reducing the deformation resistance of the magnesium alloy.
[0028] In some alternative implementations, the pulse current density corresponding to the pretreated magnesium plate can be 100 A / mm². 2 ~150A / mm 2 For example, 100A / mm 2 110A / mm 2 120A / mm 2 130A / mm 2 140A / mm 2 Or 150A / mm 2 etc., can also be 100A / mm 2 ~150A / mm 2 Other values within the range.
[0029] In some alternative implementations, the pulse current density corresponding to the pre-treated aluminum plate can be 60 A / mm². 2 ~100A / mm 2 For example, 60A / mm 2 70A / mm 2 80A / mm 2 90A / mm 2 Or 100A / mm 2 etc., or 60A / mm 2 ~100A / mm 2 Other values within the range.
[0030] After the pretreated aluminum plate is heated by pulsed current, the surface temperature of the resulting hot aluminum plate can be 300℃~350℃, such as 300℃, 310℃, 320℃, 330℃, 340℃ or 350℃, or other values within the range of 300℃~350℃.
[0031] If the pulse current density corresponding to the pre-treated aluminum plate is too small, or the surface temperature of the hot aluminum plate is too low, the aluminum plate will be difficult to deform within this temperature range; if the pulse current density corresponding to the pre-treated aluminum plate is too large, or the surface temperature of the hot aluminum plate is too high, the deformation of the aluminum plate will be much greater than that of the magnesium plate, causing the thickness ratio of the composite plate to not meet the preset value.
[0032] S3: Hot magnesium plate and hot aluminum plate are rolled in a single pass to obtain magnesium-aluminum composite plate.
[0033] In some optional embodiments, the magnesium plate in the magnesium-aluminum composite panel can be one layer or multiple layers; the aluminum plate can be one layer or multiple layers. For example, the magnesium-aluminum composite panel can be a stacked aluminum plate-magnesium plate, or a stacked aluminum plate-magnesium plate-aluminum plate.
[0034] In some alternative implementations, the reduction in a single rolling pass can be 40% to 50%, such as 40%, 42%, 45%, 48%, or 50%, or other values within the range of 40% to 50%.
[0035] If the reduction in a single rolling pass is less than 40%, it is not conducive to the composite of magnesium-aluminum composite plates, resulting in defects such as local pores in the composite plates; if the reduction in a single rolling pass is greater than 50%, it is not conducive to the subsequent rolling of composite strips.
[0036] In some alternative implementations, the rolling tension during a single pass can be 45N to 55N, such as 45N, 48N, 50N, 52N or 55N, or other values within the range of 45N to 55N.
[0037] The aforementioned single-pass rolling can be performed, for example, using a twin-roll reversible rolling mill. The rolling process is carried out under a protective atmosphere, which may include, for example, argon, ammonia decomposition gas, or carbon dioxide. This protective atmosphere during the rolling process prevents interfacial oxidation, thus facilitating a good interfacial bond in the magnesium-aluminum composite plate.
[0038] In some alternative embodiments, after a single rolling pass, the surface temperature of the magnesium-aluminum composite plate can be 160°C to 180°C, such as 160°C, 165°C, 170°C, 175°C, or 180°C, or other values within the range of 160°C to 180°C.
[0039] In some alternative implementations, the thickness of the magnesium-aluminum composite plate can be 1mm to 2.5mm, such as 1mm, 1.5mm, 2mm or 2.5mm, or other values within the range of 1mm to 2.5mm.
[0040] S4: The magnesium-aluminum composite plate is subjected to first annealing, straightening, multi-pass rolling and intermediate annealing to obtain magnesium-aluminum composite strip.
[0041] In some alternative embodiments, the first annealing is carried out at 280°C to 320°C (e.g., 280°C, 290°C, 300°C, 310°C or 320°C, etc.) for 1 hour to 3 hours (e.g., 1 hour, 1.5 hours, 2 hours, 2.5 hours or 3 hours, etc.).
[0042] In some alternative implementations, during the multi-pass rolling process, the reduction per pass can be 10% to 15%, such as 10%, 11%, 12%, 13%, 14%, or 15%, or other values within the range of 10% to 15%.
[0043] In multi-pass rolling, if the reduction in each pass is less than 10%, it is not conducive to further improving the interfacial bonding of the composite strip; if the reduction in each pass is greater than 15%, it is easy to cause edge cracking and local failure of the composite strip.
[0044] In some alternative implementations, the rolling tension during multi-pass rolling can be 18N~22N, such as 18N, 19N, 20N, 21N or 22N, or other values within the range of 18N~22N.
[0045] The aforementioned multi-pass rolling can be carried out, for example, using a four-high reversible rolling mill, and the rolling process is cold rolling.
[0046] In some alternative embodiments, the intermediate annealing can be performed 3 to 5 times, such as 3, 4 or 5 times. Each intermediate annealing can be held at 280℃ to 320℃ (such as 280℃, 290℃, 300℃, 310℃ or 320℃, etc.) for 0.5h to 1h (such as 0.5h, 0.75h or 1h, etc.).
[0047] By performing the aforementioned intermediate annealing, the residual stress and hardness of the composite strip can be reduced, which is beneficial for further rolling.
[0048] In some alternative embodiments, the thickness of the magnesium-aluminum composite strip can be 0.5mm to 0.8mm, such as 0.5mm, 0.6mm, 0.7mm or 0.8mm, or other values within the range of 0.5mm to 0.8mm.
[0049] In some alternative implementations, the flatness of the magnesium-aluminum composite strip does not exceed 0.2 mm / m.
[0050] S5: The magnesium-aluminum composite strip is subjected to a second annealing and cold rolling to obtain magnesium-aluminum composite foil.
[0051] In some alternative embodiments, the second annealing can be carried out at 180°C to 220°C (e.g., 180°C, 190°C, 200°C, 210°C, or 220°C) for 0.5h to 1h (e.g., 0.5h, 0.75h, or 1h).
[0052] If the temperature of the second annealing exceeds 220℃, it will be detrimental to the control of the strength and hardness of the composite foil.
[0053] In some alternative implementations, the rolling tension during the cold rolling process can be 4N to 6N, such as 4N, 4.5N, 5N, 5.5N or 6N, or other values within the range of 4N to 6N.
[0054] In some alternative implementations, the cold rolling reduction can be 5% to 10%, such as 5%, 6%, 7%, 8%, 9% or 10%, or other values within the range of 5% to 10%.
[0055] If the cold rolling reduction is less than 5%, the number of rolling passes and processes increases; if the cold rolling reduction is greater than 10%, it is not conducive to the control of the composite foil shape.
[0056] The aforementioned cold rolling process can be carried out, for example, on a 20-roll precision rolling mill.
[0057] In some alternative embodiments, the thickness of the magnesium-aluminum composite foil can be 0.05mm to 0.15mm, such as 0.05mm, 0.1mm or 0.15mm, or other values within the range of 0.05mm to 0.15mm.
[0058] In some alternative implementations, the flatness of the magnesium-aluminum composite foil does not exceed 5 μm / m.
[0059] During the above preparation process, the precision, flatness, and thickness of each composite material can be tested using a plate shape tester.
[0060] Accordingly, the present invention also provides a magnesium-aluminum composite foil, which is prepared by the above-described preparation method.
[0061] In this magnesium-aluminum composite foil, magnesium and aluminum layers are arranged alternately, and the total number of magnesium and aluminum layers can be 2, 3, 4, or more. Preferably, the outermost layer is an aluminum layer.
[0062] In some alternative embodiments, the ratio of the thickness of the original aluminum plate to the thickness of the original magnesium plate in the magnesium-aluminum composite foil is 0.25:(0.5~1), such as 0.25:0.5, 0.25:0.6, 0.25:0.7, 0.25:0.8, 0.25:0.9 or 0.25:1, etc., or other values within the range of 0.25:(0.5~1).
[0063] In some alternative embodiments, the density of the magnesium-aluminum composite foil is ≤2.5 g / cm³. 3 For example, 1.7g / cm 3 ~2.4g / cm 3.
[0064] In some alternative implementations, when the damping of the magnesium-aluminum composite foil is 0.1, Q -1 Value ≥ 0.01, such as 0.012~0.025.
[0065] In some alternative implementations, the electromagnetic shielding effectiveness of the magnesium-aluminum composite foil is 75dB to 100dB at 0MHz to 2000MHz.
[0066] In some alternative embodiments, the tensile strength of the magnesium-aluminum composite foil is 250 MPa to 320 MPa.
[0067] In some alternative embodiments, the elongation of the magnesium-aluminum composite foil is 3% to 5%.
[0068] In addition, the present invention also provides an application of the magnesium-aluminum composite foil as described above, for example, the magnesium-aluminum composite foil can be used in audio diaphragms, magnesium batteries or electromagnetic shielding products.
[0069] The features and performance of the present invention will be further described in detail below with reference to embodiments.
[0070] In the following examples and comparative examples, the magnesium plate was purchased from Shanxi Huasheng Yinguang Magnesium Industry; the aluminum plate was purchased from Shenzhen Shunjinda Metal Materials Co., Ltd.
[0071] Example 1 This embodiment provides a magnesium-aluminum composite foil, the preparation method of which includes: S1: The original magnesium plate and the original aluminum plate are pre-annealed respectively, and the surface oxide layer is removed by grinding to obtain the pre-treated magnesium plate and the pre-treated aluminum plate.
[0072] The original magnesium plate consisted of one roll of pure magnesium plate measuring 2mm × 150mm × 40m, which underwent pre-annealing at 350℃ for 2 hours. The original aluminum plate consisted of two rolls of pure aluminum plate measuring 1mm × 150mm × 40m, which underwent pre-annealing at 350℃ for 2 hours.
[0073] S2: The pretreated magnesium plate and the pretreated aluminum plate are heated by pulsed current to obtain hot magnesium plate and hot aluminum plate.
[0074] The pulse current density corresponding to the pretreated magnesium plate is 120 A / mm². 2 The pulse current density corresponding to the pretreated aluminum plate is 80A / mm². 2 The surface temperature of the resulting hot aluminum plate is 320℃.
[0075] S3: Hot magnesium plate and hot aluminum plate are rolled in a single pass on a twin-roll reversible rolling mill in the order of aluminum plate-magnesium plate-aluminum plate to obtain magnesium-aluminum composite plate (specifically aluminum-magnesium-aluminum composite plate).
[0076] The single-pass rolling reduction was 50%, and the rolling tension was 50N. The rolling process was carried out under ammonia decomposition gas. After single-pass rolling, the surface temperature of the magnesium-aluminum composite plate was 160℃. The thickness of the magnesium-aluminum composite plate was 2mm.
[0077] S4: The magnesium-aluminum composite plate is subjected to first annealing, straightening, multi-pass rolling and intermediate annealing to obtain magnesium-aluminum composite strip.
[0078] The first annealing was performed at 300℃ for 1 hour. Multi-pass rolling was carried out on a four-high reversible mill, with a reduction of 15% per pass and a rolling tension of 20N; the rolling process was cold rolling. The intermediate annealing was performed five times, with each intermediate annealing held at 300℃ for 0.5 hours. The thickness of the magnesium-aluminum composite strip was 0.8 mm, and the straightness of the magnesium-aluminum composite strip did not exceed 0.2 mm / m.
[0079] S5: The magnesium-aluminum composite strip is subjected to a second annealing and cold rolling to obtain magnesium-aluminum composite foil.
[0080] The second annealing was carried out at 200℃ for 0.5 hours. The cold rolling process was performed on a 20-roll precision rolling mill equipped with AGC (while the shape accuracy and thickness accuracy of the composite foil were simultaneously tested using a shape gauge), with a rolling tension of 5N. The cold rolling reduction was 10%. The thickness of the magnesium-aluminum composite foil was 0.1mm, and the flatness of the magnesium-aluminum composite foil did not exceed 5μm / m.
[0081] Example 2 This embodiment provides a magnesium-aluminum composite foil, the preparation method of which includes: S1: The original magnesium plate and the original aluminum plate are pre-annealed respectively, and the surface oxide layer is removed by grinding to obtain the pre-treated magnesium plate and the pre-treated aluminum plate.
[0082] The original magnesium plate was a Mg-Li alloy sheet with dimensions of 1.5mm × 150mm × 40m, in one roll, and its pre-annealing treatment was carried out at 250℃ for 1 hour. The original aluminum plate was a pure aluminum sheet with dimensions of 0.5mm × 150mm × 40m, in one roll, and its pre-annealing treatment was carried out at 300℃ for 1 hour.
[0083] S2: The pretreated magnesium plate and the pretreated aluminum plate are heated by pulsed current to obtain hot magnesium plate and hot aluminum plate.
[0084] The pulse current density corresponding to the pretreated magnesium plate is 100 A / mm². 2The pulse current density corresponding to the pretreated aluminum plate is 100A / mm². 2 The surface temperature of the resulting hot aluminum plate is 350℃.
[0085] S3: Hot magnesium plate and hot aluminum plate are rolled in a single pass on a twin-roll reversible rolling mill in the order of aluminum plate-magnesium plate to obtain magnesium-aluminum composite plate (specifically aluminum-magnesium composite plate).
[0086] The single-pass rolling reduction was 50%, and the rolling tension was 50 N. The rolling process was carried out under a carbon dioxide atmosphere. After single-pass rolling, the surface temperature of the magnesium-aluminum composite plate was 160℃. The thickness of the magnesium-aluminum composite plate was 1 mm.
[0087] S4: The magnesium-aluminum composite plate is subjected to first annealing, straightening, multi-pass rolling and intermediate annealing to obtain magnesium-aluminum composite strip.
[0088] The first annealing was performed at 300℃ for 1 hour. Multi-pass rolling was carried out on a four-high reversible mill, with a reduction of 15% per pass and a rolling tension of 20N; the rolling process was cold rolling. The intermediate annealing was performed five times, with each intermediate annealing held at 300℃ for 0.5 hours. The thickness of the magnesium-aluminum composite strip was 0.5 mm, and the straightness of the magnesium-aluminum composite strip did not exceed 0.2 mm / m.
[0089] S5: The magnesium-aluminum composite strip is subjected to a second annealing and cold rolling to obtain magnesium-aluminum composite foil.
[0090] The second annealing was carried out at 200℃ for 0.5 hours. The cold rolling process was performed on a 20-roll precision rolling mill equipped with AGC (while the shape accuracy and thickness accuracy of the composite foil were simultaneously checked by a shape gauge), with a rolling tension of 5N. The cold rolling reduction was 8%. The thickness of the magnesium-aluminum composite foil was 0.05mm, and the flatness of the magnesium-aluminum composite foil did not exceed 5μm / m.
[0091] SEM images of the magnesium-aluminum composite foil are as follows: Figure 1 As shown, by Figure 1 It can be seen that: Figure 1 (a) is a magnesium / aluminum composite strip. Figure 1 In the middle (b), the composite foil material is shown. As can be seen from the figure, the composite strip and the composite foil material have a good interface bond, and the aluminum layer and magnesium layer have uniform thickness.
[0092] The EBSD microstructure of the magnesium-aluminum composite foil is shown below. Figure 2 As shown, by Figure 2 It can be seen that: magnesium layer ( Figure 2 (as shown in a) and aluminum layer ( Figure 2 (As shown in b) all have fine equiaxed crystal structures.
[0093] In this embodiment, the tensile curves of the magnesium-aluminum composite strip and the magnesium-aluminum composite foil are as follows: Figure 3 As shown, by Figure 3 It can be seen that as the rolling reduction increases, the strength of magnesium / aluminum composite foil increases, while the elongation decreases.
[0094] Example 3 This embodiment provides a magnesium-aluminum composite foil, the preparation method of which includes: S1: The original magnesium plate and the original aluminum plate are pre-annealed respectively, and the surface oxide layer is removed by grinding to obtain the pre-treated magnesium plate and the pre-treated aluminum plate.
[0095] The original magnesium plate consisted of one roll of pure magnesium plate measuring 3mm × 150mm × 40m, which underwent pre-annealing at 350℃ for 2 hours. The original aluminum plate consisted of two rolls of pure aluminum plate measuring 1mm × 150mm × 40m, which underwent pre-annealing at 350℃ for 2 hours.
[0096] S2: The pretreated magnesium plate and the pretreated aluminum plate are heated by pulsed current to obtain hot magnesium plate and hot aluminum plate.
[0097] The pulse current density corresponding to the pretreated magnesium plate is 150 A / mm². 2 The pulse current density corresponding to the pretreated aluminum plate is 100A / mm². 2 The surface temperature of the resulting hot aluminum plate is 350℃.
[0098] S3: Hot magnesium plate and hot aluminum plate are rolled in a single pass on a twin-roll reversible rolling mill in the order of aluminum plate-magnesium plate-aluminum plate to obtain magnesium-aluminum composite plate (specifically aluminum-magnesium-aluminum composite plate).
[0099] The reduction in a single pass is 50%, and the rolling tension during a single pass is 50 N; the rolling process is carried out under ammonia decomposition gas. After a single pass, the surface temperature of the magnesium-aluminum composite plate is 160℃. The thickness of the magnesium-aluminum composite plate is 2.5 mm.
[0100] S4: The magnesium-aluminum composite plate is subjected to first annealing, straightening, multi-pass rolling and intermediate annealing to obtain magnesium-aluminum composite strip.
[0101] The first annealing was performed at 300℃ for 1 hour. Multi-pass rolling was carried out on a four-high reversible mill, with a reduction of 15% per pass and a rolling tension of 20N. The rolling process was cold rolling. The intermediate annealing was performed five times, with each intermediate annealing held at 300℃ for 0.5 hours. The thickness of the magnesium-aluminum composite strip was 0.6 mm, and the straightness of the magnesium-aluminum composite strip did not exceed 0.2 mm / m.
[0102] S5: The magnesium-aluminum composite strip is subjected to a second annealing and cold rolling to obtain magnesium-aluminum composite foil.
[0103] The second annealing was carried out at 200℃ for 0.5 hours. The cold rolling process was performed on a 20-roll precision rolling mill equipped with AGC (while the shape accuracy and thickness accuracy of the composite foil were simultaneously checked by a shape gauge), with a rolling tension of 5N. The cold rolling reduction was 10%. The thickness of the magnesium-aluminum composite foil was 0.05mm, and the flatness of the magnesium-aluminum composite foil did not exceed 5μm / m.
[0104] Example 4 This embodiment provides a magnesium-aluminum composite foil, the preparation method of which includes: S1: The original magnesium plate and the original aluminum plate are pre-annealed respectively, and the surface oxide layer is removed by grinding to obtain the pre-treated magnesium plate and the pre-treated aluminum plate.
[0105] The original magnesium plate consisted of one roll of pure magnesium plate measuring 2mm × 150mm × 40m, which underwent pre-annealing at 250℃ for 3 hours. The original aluminum plate consisted of two rolls of pure aluminum plate measuring 1mm × 150mm × 40m, which underwent pre-annealing at 250℃ for 3 hours.
[0106] S2: The pretreated magnesium plate and the pretreated aluminum plate are heated by pulsed current to obtain hot magnesium plate and hot aluminum plate.
[0107] The pulse current density corresponding to the pretreated magnesium plate is 100 A / mm². 2 The pulse current density corresponding to the pretreated aluminum plate is 100A / mm². 2 The surface temperature of the resulting hot aluminum plate is 350℃.
[0108] S3: Hot magnesium plate and hot aluminum plate are rolled in a single pass on a twin-roll reversible rolling mill in the order of aluminum plate-magnesium plate-aluminum plate to obtain magnesium-aluminum composite plate (specifically aluminum-magnesium-aluminum composite plate).
[0109] The single-pass rolling reduction was 40%, and the rolling tension was 45 N. The rolling process was carried out under an argon atmosphere. After single-pass rolling, the surface temperature of the magnesium-aluminum composite plate was 160℃. The thickness of the magnesium-aluminum composite plate was 1 mm.
[0110] S4: The magnesium-aluminum composite plate is subjected to first annealing, straightening, multi-pass rolling and intermediate annealing to obtain magnesium-aluminum composite strip.
[0111] The first annealing was performed at 280℃ for 2 hours. Multi-pass rolling was carried out on a four-high reversible mill, with a reduction of 10% per pass and a rolling tension of 18N; the rolling process was cold rolling. Intermediate annealing was performed three times, with each intermediate annealing held at 280℃ for 1 hour. The thickness of the magnesium-aluminum composite strip was 0.5 mm, and the straightness of the magnesium-aluminum composite strip did not exceed 0.2 mm / m.
[0112] S5: The magnesium-aluminum composite strip is subjected to a second annealing and cold rolling to obtain magnesium-aluminum composite foil.
[0113] The second annealing was carried out at 180℃ for 1 hour. The cold rolling process was performed on a 20-roll precision rolling mill equipped with AGC (while the shape accuracy and thickness accuracy of the composite foil were simultaneously checked by a shape gauge), with a rolling tension of 4N. The cold rolling reduction was 5%. The thickness of the magnesium-aluminum composite foil was 0.05mm, and the flatness of the magnesium-aluminum composite foil did not exceed 5μm / m.
[0114] Comparative Example 1 This comparative example provides a magnesium-aluminum composite foil, the preparation method of which is as follows: magnesium plates and aluminum plates are annealed at 350℃ for 2 hours to remove the oxide layer on the surface of magnesium plates and aluminum plates. Then, the magnesium plates and aluminum plates are heated to 400℃ for single-pass rolling and composite bonding with a reduction of 50%. The edge cracks of the composite plate are trimmed, and the rolled composite plate is annealed. The annealing temperature of each intermediate pass is 300℃ and the time is 0.5 hours. The plate is rolled to 0.1 mm in multiple passes with a reduction of 25% in each pass and a rolling temperature of 350℃.
[0115] Comparative Example 2 The difference between this comparative example and Example 1 is that in S2, a tunnel furnace is used to heat the pretreated magnesium plate and the pretreated aluminum plate respectively.
[0116] Comparative Example 3 The difference between this comparative example and Example 1 is that in S2, the pulse current density corresponding to the pretreated magnesium plate is 80 A / mm². 2 The pulse current density corresponding to the pretreated aluminum plate is 40A / mm². 2 The surface temperature of the resulting hot aluminum plate is 200℃ after the corresponding pulse current heats the pretreated aluminum plate.
[0117] Comparative Example 4 The difference between this comparative example and Example 1 is that in S2, the pulse current density corresponding to the pretreated magnesium plate is 180 A / mm². 2 The pulse current density corresponding to the pretreated aluminum plate is 120A / mm². 2 The surface temperature of the resulting hot aluminum plate is 400℃ after the corresponding pulse current heats the pretreated aluminum plate.
[0118] Comparative Example 5 The difference between this comparative example and Example 1 is that in S3, the reduction in a single rolling pass is 35%.
[0119] Comparative Example 6 The difference between this comparative example and Example 1 is that in S3, the reduction in a single rolling pass is 55%.
[0120] Comparative Example 7 The difference between this comparative example and Example 1 is that in S4, the reduction amount per pass during the multi-pass rolling process is 5%.
[0121] Comparative Example 8 The difference between this comparative example and Example 1 is that in S4, the reduction in each pass during the multi-pass rolling process is 20%.
[0122] Comparative Example 9 The difference between this comparative example and Example 1 is that intermediate annealing was not performed in S4.
[0123] Comparative Example 10 The difference between this comparative example and Example 1 is that in S5, a second annealing was not performed.
[0124] Comparative Example 11 The difference between this comparative example and Example 1 is that in S5, the temperature of the second annealing is 250°C.
[0125] Test case The performance of the magnesium-aluminum composite foils prepared in Examples 1-4 and Comparative Examples 1-11 was compared, and the results are shown in Table 1.
[0126] Density was tested using the Archimedes displacement method; mechanical properties were tested on a universal testing machine according to the GB / T 228.1-2021 standard; damping performance was tested using a DMA device according to the GB / T 18258 method; and electromagnetic shielding performance was tested on a vector network tester according to the GB / T 30142-2013 standard.
[0127] Table 1 Performance Results
[0128] As can be seen from Table 1, the magnesium-aluminum composite foils prepared in Examples 1-4 of the present invention have better corrosion resistance, damping and electromagnetic shielding effects compared with the magnesium-aluminum composite foils prepared in Comparative Examples 1-11.
[0129] In summary, the method provided by this invention can achieve good interfacial bonding and plate shape control of magnesium-aluminum composite foil. The resulting magnesium-aluminum composite foil has lightweight, corrosion resistance, and good damping, electromagnetic shielding, and high energy density properties, and can be widely used in audio diaphragms, magnesium batteries, electromagnetic shielding and other fields.
[0130] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.
Claims
1. A method for preparing a magnesium-aluminum composite foil, characterized in that, Includes the following steps: The original magnesium plate and the original aluminum plate were pre-annealed and the surface oxide layer was removed to obtain pre-treated magnesium plate and pre-treated aluminum plate. The pretreated magnesium plate and the pretreated aluminum plate are heated by pulsed current to obtain hot magnesium plate and hot aluminum plate; The hot magnesium plate and the hot aluminum plate are rolled in a single pass to obtain a magnesium-aluminum composite plate. The magnesium-aluminum composite plate is subjected to a first annealing, straightening, multi-pass rolling and intermediate annealing to obtain magnesium-aluminum composite strip; The magnesium-aluminum composite strip is subjected to a second annealing and cold rolling to obtain magnesium-aluminum composite foil.
2. The preparation method according to claim 1, characterized in that, Both the original magnesium plate and the original aluminum plate were pre-annealed at 250℃~350℃ for 1h~3h.
3. The preparation method according to claim 1, characterized in that, The pulse current density corresponding to the pretreated magnesium plate is 100A / mm². 2 ~150A / mm 2 The pulse current density corresponding to the pretreated aluminum plate is 60A / mm². 2 ~100A / mm 2 The surface temperature of the hot aluminum plate is 300℃~350℃.
4. The preparation method according to claim 1, characterized in that, The preparation of the magnesium-aluminum composite plate includes at least one of the following characteristics: Feature 1: The reduction in a single rolling pass is 40%~50%; Feature 2: The rolling tension during single-pass rolling is 45N~55N; Feature 3: After a single rolling pass, the surface temperature of the magnesium-aluminum composite plate is 160℃~180℃; Feature 4: The thickness of the magnesium-aluminum composite plate is 1mm~2.5mm.
5. The preparation method according to claim 1, characterized in that, The preparation of the magnesium-aluminum composite strip includes at least one of the following characteristics: Feature 5: The first annealing is carried out at 280℃~320℃ for 1h~3h; Feature 6: In multi-pass rolling, the reduction per pass is 10%~15%; Feature 7: The rolling tension during multi-pass rolling is 18N~22N; feature 8: The intermediate annealing is performed 3 to 5 times, and each intermediate annealing is held at 280℃ to 320℃ for 0.5h to 1h; Feature 9: The thickness of the magnesium-aluminum composite strip is 0.5mm~0.8mm; Feature 10: The flatness of the magnesium-aluminum composite strip does not exceed 0.2 mm / m.
6. The preparation method according to claim 1, characterized in that, The preparation of the magnesium-aluminum composite foil includes at least one of the following features: Feature 11: The second annealing is carried out at 180℃~220℃ for 0.5h~1h; Feature 12: The rolling tension during the cold rolling process is 4N~6N; Feature 13: The reduction in cold rolling is 5%~10%; Feature 14: The thickness of the magnesium-aluminum composite foil is 0.05mm~0.15mm; Feature 15: The flatness of the magnesium-aluminum composite foil does not exceed 5 μm / m.
7. A magnesium-aluminum composite foil, characterized in that, The magnesium-aluminum composite foil is prepared by the preparation method according to any one of claims 1 to 6.
8. The magnesium-aluminum composite foil according to claim 7, characterized in that, In the magnesium-aluminum composite foil, the ratio of the thickness of the original aluminum plate to the thickness of the original magnesium plate is 0.25:(0.5~1).
9. The magnesium-aluminum composite foil according to claim 7 or 8, characterized in that, The magnesium-aluminum composite foil has at least one of the following characteristics: Feature 16: The density of the magnesium-aluminum composite foil is ≤2.5 g / cm³. 3 ; Feature 17: When the damping of the magnesium-aluminum composite foil is 0.1, Q -1 Value ≥ 0.01; Feature 18: The electromagnetic shielding effectiveness of the magnesium-aluminum composite foil at 0MHz~2000MHz is 75dB~100dB; Feature 19: The tensile strength of the magnesium-aluminum composite foil is 250MPa~320MPa; Feature 20: The elongation of the magnesium-aluminum composite foil is 3%~5%.
10. An application of the magnesium-aluminum composite foil as described in any one of claims 7 to 9, characterized in that, The magnesium-aluminum composite foil is used in audio diaphragms, magnesium batteries, or electromagnetic shielding products.