Magnesium-aluminum composite sheet reinforced with zinc interlayer and method for producing the same

Abstract

The present application relates to the technical field of magnesium-aluminum layered composite material, in particular to a zinc interlayer reinforced magnesium-aluminum composite plate and a preparation method thereof.The preparation method comprises: respectively performing heat preservation treatment on a magnesium plate, an aluminum plate and a zinc foil at different temperatures; then stacking the magnesium plate, the aluminum plate and the zinc foil after the heat preservation treatment in the order of aluminum plate / zinc foil / magnesium plate / zinc foil / aluminum plate; and immediately performing single-pass rolling to form a magnesium-aluminum composite plate blank; and then performing multi-pass hot rolling on the magnesium-aluminum composite plate blank.The preparation method provided in the embodiments of the present application effectively improves the interface bonding performance and comprehensive mechanical properties of the magnesium-aluminum composite plate, wherein the interface bonding strength of the magnesium-aluminum composite plate is 75-90 MPa, the tensile strength is 320-340 MPa, and the elongation rate is 15-18%.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of magnesium-aluminum layered composite material, in particular to a zinc interlayer reinforced magnesium-aluminum composite plate and a preparation method thereof. BACKGROUND

[0002] Magnesium and magnesium alloys are widely used in the automotive, aerospace and consumer electronics industries due to their low density, high specific strength, excellent damping performance and electromagnetic shielding performance. However, their poor formability, poor corrosion resistance and low absolute strength seriously hinder their wide application. Magnesium-aluminum composite plates have broad application prospects in the fields of aerospace, automobiles, transportation, etc. due to their combination of the low density and high specific strength of magnesium alloys and the excellent formability and high corrosion resistance of aluminum alloys.

[0003] There are many methods for preparing magnesium-aluminum composite plates in the prior art, among which rolling composite has the advantages of high production efficiency, easy realization of large-scale industrial production, etc. Therefore, it has become the most rapidly developed and widely applied method for producing magnesium-aluminum composite plates.

[0004] However, there are still many problems in the preparation of magnesium-aluminum composite plates by rolling, such as the formation of a diffusion layer with a thickness of tens to hundreds of microns at the interface of the magnesium-aluminum composite plate during hot working and subsequent heat treatment. The main components of the diffusion layer are intermetallic compounds Mg 17 Al 12 and Mg2Al3, however, these intermetallic compounds are hard and brittle phases, and during the loading process of the composite plate, these intermetallic compounds are prone to become crack sources, greatly weakening the strength and plasticity of the composite plate. Therefore, how to avoid the formation of a large number of intermetallic compounds at the interface of the magnesium-aluminum composite plate has become a research hotspot at home and abroad.

[0005] Researchers have improved the interface structure of magnesium-aluminum composite plates by adding metal powder at the interface to reduce the number of intermetallic compounds and thereby improve the interface bonding strength of the composite plate. Compared with powder, metal interlayers can be more uniformly distributed in the interface of the composite plate, which is expected to fully play a role in improving the interface bonding strength. However, the question of what kind of metal interlayer to use and how to operate the metal interlayer to improve the performance of the magnesium-aluminum composite plate are technical difficulties that researchers need to solve.

[0006] In view of this, the present application is proposed. SUMMARY

[0007] The purpose of the present application is to provide a zinc interlayer reinforced magnesium-aluminum composite plate and a preparation method thereof. The present application provides a new preparation method which can improve the above-mentioned problems of the prior art.

[0008] The present application is implemented as follows:

[0009] In a first aspect, the present application provides a method for preparing a magnesium-aluminum composite sheet reinforced by a zinc interlayer, comprising:

[0010] Step 1: subjecting a magnesium sheet, an aluminum sheet and a zinc foil to heat preservation treatment at different temperatures, respectively, wherein the temperature of the aluminum sheet is lower than that of the magnesium sheet, and the temperature difference between the two is 80-100℃, and the temperature of the magnesium sheet is higher than that of the zinc foil, and the temperature difference between the two is 30-60℃;

[0011] Step 2: stacking the magnesium sheet, the aluminum sheet and the zinc foil after heat preservation treatment in the order of aluminum sheet / zinc foil / magnesium sheet / zinc foil / aluminum sheet, and then immediately performing single-pass rolling to form a magnesium-aluminum composite sheet blank;

[0012] Step 3: performing multi-pass hot rolling on the magnesium-aluminum composite sheet blank to form the magnesium-aluminum composite sheet.

[0013] In an optional embodiment, the heat preservation temperature of the magnesium sheet is 300-380℃, and the heat preservation time is 24-45min;

[0014] The heat preservation temperature of the aluminum sheet is 250-300℃, and the heat preservation time is 20-30min;

[0015] The heat preservation temperature of the zinc foil is 290-350℃, and the heat preservation time is 10-15min.

[0016] In an optional embodiment, the heat preservation treatment in step 1 is performed in an air atmosphere.

[0017] In an optional embodiment, the thickness ratio of the aluminum sheet to the magnesium sheet in step 1 is (1:2)-(2:1), and the thickness of the zinc foil is 0.01-0.2mm;

[0018] Preferably, the thickness of the magnesium sheet is 1-2mm.

[0019] In an optional embodiment, the deformation amount of single-pass rolling in step 2 is 45-60%.

[0020] In an optional embodiment, the number of passes of rolling in step 3 is at least 2.

[0021] The conditions of each pass of rolling are as follows: the temperature is 230-280℃, the time is 10-15min, the deformation amount of each pass of rolling is 40-50%, and the heat preservation of each pass is performed in an air atmosphere.

[0022] In an optional embodiment, the aluminum sheet in step 1 is a 5000 series or 6000 series aluminum alloy sheet, the magnesium sheet is a Mg-Al-Zn series or Mg-Zn-Zr series magnesium alloy sheet, and the zinc foil is a pure zinc foil or a zinc alloy foil.

[0023] In a second aspect, the present application provides a magnesium-aluminum composite plate reinforced by a zinc interlayer, which is prepared by the method for preparing a magnesium-aluminum composite plate reinforced by a zinc interlayer according to any one of the preceding embodiments.

[0024] In an optional embodiment, the magnesium-aluminum composite plate has good interface bonding, no intermetallic compound is formed between the aluminum layer and the zinc layer, and a diffusion layer mainly composed of MgZn2 phase is formed between the magnesium layer and the zinc layer, and the thickness of the diffusion layer is less than or equal to 2 μm.

[0025] Preferably, the magnesium layer in the magnesium-aluminum composite plate has an average grain size less than or equal to 3.5 μm, the basal plane texture intensity of the magnesium layer is less than or equal to 9.2, and the texture intensity of the aluminum layer is less than or equal to 4.2.

[0026] In an optional embodiment, the magnesium-aluminum composite plate has an interface bonding strength of 75-90 MPa, a tensile strength of 320-340 MPa, and an elongation of 15-18%.

[0027] The present application has the following beneficial effects: the embodiments of the present application perform heat preservation treatment on the magnesium plate, the aluminum plate and the zinc foil at different temperatures, which helps to fully exert the plastic deformation capacity of the magnesium plate, the aluminum plate and the zinc foil, forms a clear temperature gradient among the magnesium plate, the aluminum plate and the zinc foil, reduces the difference in deformation resistance among the magnesium plate, the aluminum plate and the zinc foil during rolling, and makes the magnesium plate, the aluminum plate and the zinc foil obtain similar plastic deformation during single-pass rolling. The introduction of the ultra-thin zinc foil can further realize the rolling and compounding of the magnesium-aluminum composite plate at a lower temperature, coordinate the deformation of the magnesium plate and the aluminum plate, refine the average grain size of the magnesium layer, weaken the texture intensity of the composite plate, and improve the plastic forming capacity of the magnesium-aluminum composite plate. At the same time, single-pass rolling combined with multi-pass rolling is beneficial to realizing good metallurgical bonding at the interfaces between the magnesium layer and the zinc layer and between the aluminum layer and the zinc layer, and forming an extremely thin element interdiffusion layer near the interface between the magnesium layer and the zinc layer, which significantly improves the interface bonding performance of the magnesium-aluminum composite plate. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope, and other related drawings can also be obtained by those skilled in the art without paying creative labor on the premise of not deviating from the concept of the present application.

[0029] Figure 1 FIG. 1 shows the interface SEM image of the magnesium-aluminum composite plate prepared in Example 1;

[0030] Figure 2 FIG. 2 shows the interface EBSD image of the magnesium-aluminum composite plate prepared in Example 1;

[0031] Figure 3 Figure 1 shows the tensile mechanical properties of the magnesium-aluminum composite plate prepared in Example 1. DETAILED DESCRIPTION

[0032] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below. If specific conditions are not specified in the embodiments, the conventional conditions or the conditions recommended by the manufacturers are adopted. If the manufacturers of the reagents or instruments are not specified, the conventional products that can be purchased in the market are adopted.

[0033] The embodiments of the present application provide a preparation method of a zinc-interlayer-reinforced magnesium-aluminum composite plate, comprising:

[0034] Step 1, heat preservation treatment;

[0035] The magnesium plate, the aluminum plate and the zinc foil are subjected to heat preservation treatment at different temperatures. The melting point of zinc is low (about 420℃), and the use of zinc as the intermediate layer of the magnesium / aluminum composite plate is beneficial to the good bonding of the composite plate at a lower temperature. Moreover, zinc and magnesium are both close-packed hexagonal crystal structures, which is beneficial to the coordination of the deformation of magnesium and aluminum during the deformation process, and is expected to improve the plastic forming ability of the magnesium / aluminum composite plate.

[0036] The temperature of the aluminum plate is lower than that of the magnesium plate, and the temperature difference between the two is 80-100℃, such as 80℃, 85℃, 90℃, 95℃ and 100℃, or any value between 80-100℃. The temperature of the magnesium plate is higher than that of the zinc foil, and the temperature difference between the two is 30-60℃, such as 30℃, 35℃, 40℃, 45℃, 50℃, 55℃ and 60℃, or any value between 30-60℃.

[0037] The heat preservation temperature of the magnesium plate is 300-380℃, and the heat preservation time is 24-45min; for example, the temperature is 300℃, 310℃, 320℃, 330℃, 340℃, 350℃, 360℃, 370℃ and 380℃, or any value between 300-380℃. The time is 24min, 30min, 35min, 40min and 45min, or any value between 24-45min.

[0038] The heat preservation temperature of the aluminum plate is 250-300℃, and the heat preservation time is 20-30min; for example, the temperature is 250℃, 260℃, 270℃, 280℃, 290℃ and 300℃, or any value between 250-300℃. The time is 20min, 21min, 22min, 23min, 24min, 25min, 26min, 27min, 28min, 29min and 30min, or any value between 20-30min.

[0039] The holding temperature of the zinc foil is 290-350℃, and the holding time is 10-15min. For example, 290℃, 300℃, 310℃, 320℃, 330℃, 340℃ and 350℃, etc. between any value of 290-350℃. Time is 10min, 11min, 12min, 13min, 14min and 15min, etc. between any value of 10-15min.

[0040] The present application limits the holding temperature of the magnesium plate, the aluminum plate and the zinc foil and limits the temperature difference, which helps to fully exert the plastic deformation capacity of the magnesium plate, the aluminum plate and the zinc foil, so that the magnesium plate, the aluminum plate and the zinc foil form a clear temperature gradient, which is beneficial to reduce the difference in deformation resistance between the magnesium plate, the aluminum plate and the zinc foil during rolling, so that the magnesium plate, the aluminum plate and the zinc foil obtain similar plastic deformation during rolling, which is beneficial to improve the performance of the magnesium-aluminum composite plate.

[0041] Further, the above-mentioned holding heat treatment is carried out in an air atmosphere. The present application adopts an air atmosphere, and the zinc foil can still maintain good oxidation resistance, which is beneficial to the interface bonding of the composite plate during rolling, thereby improving the comprehensive mechanical properties of the composite plate.

[0042] The thickness ratio of the aluminum plate and the magnesium plate in step 1 is (1:2)-(2:1), for example, 1:2, 1:1 and 2:1, etc. between any value of (1:2)-(2:1). The thickness of the magnesium plate is 1-2mm, for example, 1mm, 1.5mm and 2mm, etc. between any value of 1-2mm.

[0043] The thickness of the zinc foil is 0.01-0.2mm. For example, 0.01mm, 0.05mm, 0.1mm, 0.15mm and 0.2mm, etc. between any value of 0.01-0.2mm. Selecting an ultra-thin zinc foil can further realize the rolling and compounding of the magnesium-aluminum composite plate at a lower temperature, coordinate the deformation of the magnesium plate and the aluminum plate, refine the average grain size of the magnesium layer, weaken the texture strength of the composite plate, and improve the plastic forming ability of the magnesium-aluminum composite plate.

[0044] The above-mentioned aluminum plate is a 5000 series or 6000 series aluminum alloy plate, the magnesium plate is a Mg-Al-Zn series or Mg-Zn-Zr series magnesium alloy plate, and the zinc foil is a pure zinc foil or a zinc alloy foil.

[0045] Step 2, single-pass rolling;

[0046] The magnesium plate, the aluminum plate and the zinc foil after the heat preservation treatment are stacked in the order of aluminum plate / zinc foil / magnesium plate / zinc foil / aluminum plate, and then immediately subjected to single-pass rolling to form a magnesium-aluminum composite plate blank; wherein the deformation amount of the single-pass rolling is 45-60%, for example, 45%, 50%, 55% and 60% or any value between 45-60%.

[0047] Step 3, multi-pass rolling;

[0048] The magnesium-aluminum composite plate blank is subjected to multi-pass hot rolling to form the magnesium-aluminum composite plate. The multi-pass hot rolling adopted in the embodiment of the present application is beneficial to achieving good metallurgical bonding at the interfaces of the magnesium layer and the zinc layer and the aluminum layer and the zinc layer, and forming an extremely thin element interdiffusion layer near the interface of the magnesium layer and the zinc layer, thereby significantly improving the interface bonding performance of the magnesium-aluminum composite plate.

[0049] Specifically, the number of passes of the multi-pass hot rolling is at least 2; and the conditions of each pass are as follows: the temperature is 230-280℃, the time is 10-15min, and the deformation amount of each pass is 40-50%. Specifically, the temperature is 230℃, 240℃, 250℃, 260℃, 270℃ and 280℃ or any value between 230-280℃. The time is 10min, 11min, 12min, 13min, 14min and 15min or any value between 10-15min. The deformation amount is 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49% and 50% or any value between 40-50%.

[0050] Each pass of heat preservation is carried out in an air atmosphere.

[0051] In a second aspect, the present application provides a zinc-interlayer-enhanced magnesium-aluminum composite plate prepared by the preparation method of the zinc-interlayer-enhanced magnesium-aluminum composite plate according to any one of the preceding embodiments.

[0052] Specifically, the magnesium-aluminum composite plate has good interface bonding, no intermetallic compound is formed between the aluminum layer and the zinc layer, a diffusion layer mainly composed of MgZn2 phase is formed between the magnesium layer and the zinc layer, and the thickness of the diffusion layer is ≤2μm; the average grain size of the magnesium layer in the magnesium-aluminum composite plate is ≤3.5μm, the basal plane texture strength of the magnesium layer is ≤9.2, and the texture strength of the aluminum layer is ≤4.2. The interface bonding strength of the magnesium-aluminum composite plate is 75-90MPa, the tensile strength is 320-340MPa, and the elongation is 15-18%.

[0053] The features and performances of the present application are further described in detail below in combination with embodiments.

[0054] Embodiment 1

[0055] This invention provides a method for preparing a zinc interlayer reinforced magnesium-aluminum composite plate, comprising:

[0056] S1, Thermal insulation and heat treatment;

[0057] 1mm thick 6061 aluminum plate, 0.05mm thick zinc foil, and 2mm thick AZ31 magnesium plate were subjected to heat treatment at different temperatures and for different times. The heat treatment of AZ31 magnesium plate was 350℃ for 30min, the heat treatment of 6061 aluminum plate was 260℃ for 25min, and the heat treatment of zinc foil was 300℃ for 10min. All heat treatments were carried out in an air heat treatment furnace.

[0058] S2, single-pass rolling;

[0059] After heat insulation treatment, magnesium plates, aluminum plates, and zinc foils are stacked in the order of aluminum plate / zinc foil / magnesium plate / zinc foil / aluminum plate and immediately subjected to single-pass rolling forming, wherein the single-pass rolling deformation is 60%, forming a magnesium-aluminum composite slab blank.

[0060] S3, multi-pass rolling;

[0061] The prepared magnesium-aluminum composite slab was then subjected to two rolling passes. The first rolling pass was at a temperature of 250℃ and a holding time of 10 minutes, with the holding treatment being carried out in an air atmosphere. The rolling deformation was 40%. The second rolling pass was at a temperature of 240℃ and a holding time of 10 minutes, with the holding treatment being carried out in an air atmosphere. The rolling deformation was 50%. Finally, a magnesium-aluminum composite slab reinforced with a zinc interlayer was obtained.

[0062] Characterization

[0063] The magnesium-aluminum composite plate prepared in Example 1 was characterized, and the results are shown in [reference needed]. Figures 1 to 3 ,in Figure 1 SEM image showing the interface of magnesium-aluminum composite plate; Figure 2 EBSD diagram showing the interface of magnesium-aluminum composite panel; Figure 3 This diagram shows the tensile mechanical properties of magnesium-aluminum composite panels.

[0064] like Figures 1 to 3 As shown, the magnesium-aluminum composite plate exhibits good interfacial bonding. The zinc layer is approximately 7 μm thick, and no intermetallic compounds form between the aluminum and zinc layers. A diffusion layer, primarily composed of the MgZn2 phase, forms at the magnesium-zinc interface, with a thickness of approximately 1 μm. The average grain size of the magnesium layer is 3 μm, and the texture strength of the magnesium layer is 9.11, while that of the aluminum layer is 4.11. The magnesium-aluminum composite plate has a tensile strength of 330 MPa, an elongation of 16%, and an interfacial bonding strength of 85 MPa.

[0065] Example 2

[0066] The embodiment provides a preparation method of a zinc-interlayer-reinforced magnesium-aluminum composite plate, and the method comprises the following steps:

[0067] S1, heat preservation heat treatment;

[0068] 1mm-thick 6082 aluminum plates, 0.1mm-thick zinc foils and 2mm-thick AZ31 magnesium plates are subjected to heat preservation treatment at different temperatures and for different time, wherein the heat preservation temperature of the AZ31 magnesium plate is 380 DEG C, the heat preservation time is 27min, the heat preservation temperature of the 6082 aluminum plate is 290 DEG C, the heat preservation time is 30min, the heat preservation temperature of the zinc foil is 320 DEG C, and the heat preservation time is 10min, and the heat preservation treatment is performed in an air heat treatment furnace.

[0069] S2, single-pass rolling;

[0070] After the heat preservation treatment, the magnesium plate, the aluminum plate and the zinc foil are stacked in the order of aluminum plate / zinc foil / magnesium plate / zinc foil / aluminum plate and are immediately subjected to single-pass rolling to form a magnesium-aluminum composite plate blank, wherein the single-pass rolling deformation is 45%.

[0071] S3, multi-pass rolling;

[0072] Subsequently, the prepared magnesium-aluminum composite plate blank is subjected to three-pass rolling, the first-pass rolling temperature is 250 DEG C, the heat preservation time is 10min, the heat preservation treatment is performed in an air atmosphere, the rolling deformation is 40%, the second-pass rolling temperature is 240 DEG C, the heat preservation time is 15min, the heat preservation treatment is performed in an air atmosphere, the rolling deformation is 40%, the third-pass rolling temperature is 235 DEG C, the heat preservation time is 12min, the heat preservation treatment is performed in an air atmosphere, and the rolling deformation is 45%, and finally, a zinc-interlayer-reinforced magnesium-aluminum composite plate is obtained.

[0073] Characterization

[0074] The magnesium-aluminum composite plate is well bonded at the interface, the thickness of the zinc layer is about 11um, no intermetallic compound is formed between the aluminum layer and the zinc layer, a diffusion layer mainly composed of MgZn2 phase is formed at the interface between the magnesium layer and the zinc layer, the thickness of the diffusion layer is about 1.5um, the average grain size of the magnesium layer is 2.7um, the texture intensity of the magnesium layer is 9.02, and the texture intensity of the aluminum layer is 4.01. The tensile strength of the magnesium-aluminum composite plate is 335MPa, the elongation is 17%, and the interface bonding strength is 90MPa.

[0075] Embodiment 3

[0076] The embodiment provides a preparation method of a zinc-interlayer-reinforced magnesium-aluminum composite plate, and the method comprises the following steps:

[0077] S1, heat preservation heat treatment;

[0078] The 1mm-thick 5052 aluminum plate, the 0.1mm-thick zinc foil and the 1mm-thick ZK60 magnesium plate were respectively subjected to heat preservation treatment at different temperatures and for different time, wherein the heat preservation temperature of the ZK60 magnesium plate was 340℃, the heat preservation time was 40min, the heat preservation temperature of the 5052 aluminum plate was 260℃, the heat preservation time was 30min, and the heat preservation temperature of the zinc foil was 300℃, the heat preservation time was 12min, and the heat preservation treatment was performed in an air heat treatment furnace.

[0079] S2, single-pass rolling;

[0080] After the heat preservation treatment, the magnesium plate, the aluminum plate and the zinc foil were immediately subjected to single-pass rolling forming in the order of aluminum plate / zinc foil / magnesium plate / zinc foil / aluminum plate, wherein the single-pass rolling deformation was 55%, and a magnesium-aluminum composite plate blank was formed.

[0081] S3, multi-pass rolling;

[0082] Subsequently, the prepared magnesium-aluminum composite plate blank was subjected to two-pass rolling, the first-pass rolling temperature was 235℃, the heat preservation time was 15min, the heat preservation treatment was performed in an air atmosphere, the rolling deformation was 45%, the second-pass rolling temperature was 230℃, the heat preservation time was 12min, the heat preservation treatment was performed in an air atmosphere, the rolling deformation was 50%, and finally a zinc-interlayer-reinforced magnesium-aluminum composite plate was obtained.

[0083] Characterization

[0084] The magnesium-aluminum composite plate had good interface bonding, the thickness of the zinc layer was about 15μm, intermetallic compounds were not formed between the aluminum layer and the zinc layer, a diffusion layer mainly composed of MgZn2 phase was formed at the interface between the magnesium layer and the zinc layer, the thickness of the diffusion layer was about 0.5μm, the average grain size of the magnesium layer was 3.3μm, the texture strength of the magnesium layer was 9.14, and the texture strength of the aluminum layer was 4.12. The tensile strength of the magnesium-aluminum composite plate was 328MPa, the elongation was 16%, and the interface bonding strength was 80MPa.

[0085] Comparative Example 1

[0086] The present comparative example provides a method for preparing a magnesium-aluminum composite plate, comprising:

[0087] The method is basically consistent with the method for preparing a composite plate provided in Example 1 in operation and conditions, and the difference lies in that no zinc foil is added between the magnesium plate and the aluminum plate.

[0088] The experimental results show that the addition of the low-melting-point zinc foil makes it difficult to achieve good bonding of the magnesium-aluminum composite plate at a lower rolling temperature, resulting in poor interface bonding performance and mechanical properties of the composite plate.

[0089] Comparative Example 2

[0090] The present comparative example provides a method for preparing a zinc-interlayer-reinforced magnesium-aluminum composite plate, comprising:

[0091] The method is basically consistent with the operation and conditions of the method for preparing the composite plate provided in Embodiment 1, except that the holding temperature of the magnesium plate and the aluminum plate is 350 DEG C.

[0092] The experimental results show that the plastic deformation ability of the magnesium plate and the aluminum plate is quite different at the same holding temperature, and it is difficult to realize the synergistic deformation of the two metals in the rolling process, resulting in a large difference in the deformation amount of the magnesium layer and the aluminum layer in the rolling process, and further significantly weakening the interface bonding performance and the comprehensive mechanical properties of the composite plate.

[0093] Comparative Example 3

[0094] The comparative example provides a method for preparing a zinc interlayer reinforced magnesium-aluminum composite plate, comprising:

[0095] The method is basically consistent with the operation and conditions of the method for preparing the composite plate provided in Embodiment 1, except that subsequent multi-pass rolling is not performed.

[0096] The experimental results show that low-temperature and short-time multi-pass rolling is beneficial to the grain refinement of the magnesium layer and the aluminum layer in the composite plate, and significantly improves the interface bonding performance and the mechanical properties of the composite plate. The interface bonding performance and the mechanical properties of the composite plate without subsequent low-temperature and short-time multi-pass rolling are poor.

[0097] Comparative Example 4

[0098] The comparative example provides a method for preparing a zinc interlayer reinforced magnesium-aluminum composite plate, comprising:

[0099] The method is basically consistent with the operation and conditions of the method for preparing the composite plate provided in Embodiment 1, except that the magnesium plate, the aluminum plate and the zinc foil are stacked in the order of aluminum plate / zinc foil / magnesium plate.

[0100] The experimental results show that the magnesium / aluminum composite plate with a two-layer structure is prone to warping during rolling, resulting in poor interface bonding of the composite plate, and greatly reducing the interface bonding performance and the comprehensive mechanical properties of the composite plate.

[0101] Comparative Example 5

[0102] The comparative example provides a method for preparing a zinc interlayer reinforced magnesium-aluminum composite plate, comprising:

[0103] The method is basically consistent with the operation and conditions of the method for preparing the composite plate provided in Embodiment 1, except that the first-pass rolling temperature of the magnesium-aluminum composite plate during multi-pass rolling is 400 DEG C.

[0104] The experimental results show that when the first pass of the multi-pass rolling is at 400 DEG C, the interface is easy to form diffusion layers with a thickness of more than tens of microns, and these diffusion layers are mainly Mg-Zn and Al-Zn-based intermetallic compounds. These hard and brittle intermetallic compounds are significantly broken in the subsequent second pass of rolling, which greatly weakens the interface bonding performance and mechanical properties of the composite plate.

[0105] Comparative Example 6

[0106] The comparative example provides a preparation method of a zinc interlayer reinforced magnesium-aluminum composite plate, comprising:

[0107] The method is basically consistent with the operation and conditions of the method for preparing the composite plate provided in Example 1, and the difference lies in that the single-pass rolling deformation is 30%.

[0108] The experimental results show that when the single-pass rolling deformation is 30%, the magnesium layer and the zinc layer and the aluminum layer and the zinc layer in the composite plate are difficult to achieve good bonding, resulting in poor interface bonding performance and mechanical properties of the composite plate.

[0109] Comparative Example 7

[0110] The comparative example provides a preparation method of a zinc interlayer reinforced magnesium-aluminum composite plate, comprising:

[0111] The method is basically consistent with the operation and conditions of the method for preparing the composite plate provided in Example 1, and the difference lies in that the aluminum plate and the zinc foil are both at a holding temperature of 260 DEG C.

[0112] The experimental results show that the plastic deformation ability of the aluminum plate and the zinc foil is quite different at the same holding temperature, and it is difficult to realize the cooperative deformation of the two metals during rolling, resulting in a large difference in the deformation amount of the aluminum layer and the zinc layer during rolling, and further significantly weakening the interface bonding performance and comprehensive mechanical properties of the composite plate.

[0113] The tensile mechanical properties and interface bonding properties of the composite plates prepared in Comparative Examples 1-7 are shown in Table 1.

[0114] Table 1 Mechanical properties test of magnesium-aluminum composite plates of Comparative Examples 1-7

[0115]

[0116] According to Table 1, compared with Comparative Examples 1-7, the magnesium-aluminum composite plate prepared in the example has higher tensile strength, elongation and interface bonding strength. It is shown that by introducing a zinc foil at the interface of the magnesium-aluminum composite plate and combining single-pass rolling and multi-pass hot rolling, the interface bonding performance and comprehensive mechanical properties of the composite plate are effectively improved.

[0117] The above merely provides the preferred embodiments of the present application, and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the principles and technical scope of the present application shall fall into the scope of the present application.

Claims

1. A method for preparing a zinc interlayer reinforced magnesium-aluminum composite plate, characterized in that, include: Step 1: The magnesium plate, aluminum plate, and zinc foil are subjected to heat preservation treatments at different temperatures. The temperature of the aluminum plate is lower than that of the magnesium plate, with a temperature difference of 80-100℃. The temperature of the magnesium plate is higher than that of the zinc foil, with a temperature difference of 30-60℃. The heat preservation temperature of the magnesium plate is 300-380℃; the heat preservation temperature of the aluminum plate is 250-300℃; and the heat preservation temperature of the zinc foil is 290-350℃. The thickness ratio of the aluminum plate to the magnesium plate in Step 1 is (1:2)-(2:1), the thickness of the zinc foil is 0.01-0.2mm, and the thickness of the magnesium plate is 1-2mm. Step 2: Stack the heat-insulated magnesium plate, aluminum plate, and zinc foil in the order of aluminum plate / zinc foil / magnesium plate / zinc foil / aluminum plate, and then immediately perform single-pass rolling to form a magnesium-aluminum composite slab; the deformation amount of single-pass rolling is 45-60%; Step 3: The magnesium-aluminum composite slab is subjected to multiple hot rolling passes to form the magnesium-aluminum composite plate; the conditions for each hot rolling pass are: temperature 230-280℃, and deformation of 40-50% per pass; The resulting magnesium-aluminum composite panel has an interfacial bonding strength of 75-90 MPa, a tensile strength of 320-340 MPa, and an elongation of 15-18%.

2. The preparation method according to claim 1, characterized in that, The heat preservation time of the magnesium plate is 24-45 minutes; The heat preservation time of the aluminum plate is 20-30 minutes; The zinc foil is kept warm for 10-15 minutes.

3. The preparation method according to claim 1 or 2, characterized in that, The heat treatment in step 1 was carried out in an air atmosphere.

4. The preparation method according to claim 1, characterized in that, In step 3, the number of rolling passes in the multi-pass hot rolling process is at least 2. The conditions for each rolling process are as follows: the time is 10-15 minutes, and each heat preservation is carried out in an air atmosphere.

5. The preparation method according to claim 1, characterized in that, The aluminum plate mentioned in step 1 is a 5000 series or 6000 series aluminum alloy plate, the magnesium plate is a Mg-Al-Zn series or Mg-Zn-Zr series magnesium alloy plate, and the zinc foil is a pure zinc foil or a zinc alloy foil.

6. A magnesium-aluminum composite plate reinforced with a zinc interlayer, characterized in that, It is prepared by the method of zinc interlayer reinforced magnesium-aluminum composite plate according to any one of claims 1-5.

7. The zinc interlayer reinforced magnesium-aluminum composite plate according to claim 6, characterized in that, The magnesium-aluminum composite plate has good interfacial bonding. No intermetallic compounds are formed between the aluminum layer and the zinc layer. A diffusion layer with MgZn2 phase as the main component is formed between the magnesium layer and the zinc layer. The thickness of the diffusion layer is ≤2μm. The magnesium-aluminum composite plate has an average grain size of ≤3.5μm for the magnesium layer, a base texture strength of ≤9.2 for the magnesium layer, and a texture strength of ≤4.2 for the aluminum layer.

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