High-performance magnesium-aluminum layered composite board material and preparation method thereof

Abstract

The invention relates to the technical field of metal layered composite plates, in particular to a high-performance magnesium-aluminum layered composite plate material and a preparation method thereof. The method aims at solving the problem that when the magnesium / aluminum layered composite material is prepared through an existing accumulative roll bonding technology, the mechanical property of the composite material is deteriorated due to the fact that a continuous brittle intermetallic compound layer is formed on an interface. According to the method, the specific asymmetric lamination initial design and the optimized accumulative roll bonding process are adopted to cooperatively regulate and control the atomic diffusion and shear deformation process at the heterogeneous interface, interface intermetallic compounds are promoted to be formed in a discontinuous blocky form, and meanwhile gradient distribution of the layered structure in the composite material is achieved. The layered composite material prepared through the method has high strength, good plasticity and excellent interface bonding performance, and the adverse effect of continuous brittleness on the comprehensive performance of the material is effectively avoided. The method is simple in process, low in cost and suitable for the fields of aerospace, automobile lightweight and the like.

Description

TECHNICAL FIELD

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

[0002] Magnesium alloy has good application prospects in aerospace, new energy vehicles, energy storage materials and other fields due to its lightweight, high specific strength and excellent damping performance as core competitiveness. However, due to its low plastic deformation capacity, it still faces the dilemma of difficulty in synergistic improvement of strength-plasticity-corrosion resistance in its application in load-bearing parts. At present, by adding specific alloying elements to Mg and combining with plastic deformation process, the tensile strength of the alloy can be greatly improved while maintaining the elongation. Among them, Mg-8Li-6Zn-1.2Y simultaneously introduces heterogeneous deformation induction (HDI) strengthening and second phase strengthening, so that the tensile strength of the alloy reaches 223 MPa, which is nearly 99% higher than that of the as-cast Mg-8Li alloy, and the elongation is maintained at 27%. However, the absolute strength and corrosion resistance of single magnesium-lithium alloy are still insufficient to support the application of high load-bearing parts. On the other hand, aluminum alloy in high corrosion-resistant light alloy can spontaneously form a dense protective film and exhibit excellent corrosion resistance, and its FCC structure endows it with good plastic deformation capacity. If aluminum alloy and magnesium-lithium alloy can be rolled together in a gradient thickness through a specific processing technology, it is expected to maintain the advantages of ultra-light core while maintaining the plasticity and toughness of the bottom and further strengthening the strength and corrosion resistance of the surface.

[0003] A light-weight high-performance layered composite armor plate material is prepared in Chinese invention CN202511093898.6, which is prepared by friction stir welding of aluminum plate and magnesium alloy to prepare a layered composite plate material. The composite plate material has light weight and high ballistic performance. However, this invention has the following disadvantages: although friction stir welding can achieve metallurgical bonding by using intense mechanical stirring and heat cycle, it is difficult to accurately suppress the growth of continuous brittle phase, and the interface is easy to become a performance short board; at the same time, it will leave a weld toe at the weld, which usually needs subsequent processing to obtain a flat surface, and needs to use consumable tools such as stirrers, which increases the production cost of the plate material and the complexity of the process.

[0004] In contrast, the accumulative roll-bonding process (ARB) relies on the mature rolling industry platform, can realize long-size and large-batch continuous production, and can directly produce flat plates through repeated rolling after cutting and stacking the plates, with high efficiency and without subsequent excessive processing. Although the layered material prepared by the accumulative roll-bonding process can significantly improve the mechanical properties of the composite plate, the intermetallic compounds formed by atomic diffusion during the heat preservation process will be broken and fractured during the stretching process due to the hard and brittle characteristics of the intermetallic compounds, thereby reducing the tensile strength of the composite plate. If the intermetallic compounds are distributed in the form of discontinuous blocks, the propagation of cracks on the interface can be limited to some extent, the strength and toughness of the interface region can be improved, and thus the bonding performance of the composite plate can be improved. Therefore, developing a method capable of accurately regulating the interfacial intermetallic compounds to exist in a beneficial form is crucial for promoting the application of high-performance layered composite materials. SUMMARY

[0005] The purpose of the present application is to provide a high-performance magnesium-aluminum layered composite plate material and a preparation method thereof to solve the problems raised in the above background.

[0006] In order to solve the above technical problems, the present application provides the following technical scheme: a preparation method of a high-performance magnesium-aluminum layered composite plate, comprising the following steps: Step 1: S11: cutting and polishing the surface of the magnesium-lithium alloy plate and the pure aluminum or aluminum alloy plate for standby; S12: stacking the alloy plate with the polished surface in the order of "Al / Mg-Li" to obtain a laminated plate; Step 2: S21: rolling the laminated plate for the first pass to obtain a composite plate, denoted as HARB 0; S22: cutting the composite plate HARB 0 into two equal parts, polishing the surface again, stacking and fixing in the order of Al / Mg-Li / Al / Mg-Li, and rolling under the same process conditions as in S21 to obtain a composite plate HARB 1; sequentially, the above method is repeated for a positive integer N times of stacking, the composite plate HARB N-1 is cut into two equal parts, and the composite plate HARB N is prepared according to the above method; S23: stacking the composite plate HARB N-1 and the composite plate HARB N after cutting the two plates to make their length and width dimensions consistent, and rolling under the same process conditions as in S21, folding the rolled plate and placing it to complete the final rolling, denoted as GARB N.

[0007] Further, in S11, the thickness ratio of the aluminum plate to the magnesium-lithium alloy plate is (0.01-0.1):1.

[0008] Further, in S21, the specific method of the first pass rolling is: the laminated plate is preheated to 300-400 DEG C, and kept for 10-20 min in argon atmosphere, the pass reduction is 40-60%, and the rolling speed is 3-6 rad / min.

[0009] Further, in S23, the HARB N plate is always stacked above the HARB N-1 plate.

[0010] Further, in S23, the Mg-Li layer in the HARB N-1 plate is placed in the core after folding and placing, and then finish rolling is performed.

[0011] Further, the high-performance magnesium-aluminum laminated composite plate material comprises 6×2 N -1 Mg-Li / Al hetero layer and 6×2 N -2 hetero interfaces, and N is the number of stacking times repeated in step S22.

[0012] Further, the Mg-Li / Al hetero layer refers to a layered structure composed of magnesium-lithium alloy layers and aluminum layers alternately, and each combination of a magnesium-lithium alloy layer and an aluminum layer constitutes a "hetero layer".

[0013] Further, the Mg-Li / Al hetero interface is the contact area between the magnesium-lithium alloy layer and the aluminum layer, that is, the interface area where the two different materials are connected to each other, and the interface intermetallic compound layer formed by the aluminum layer and the magnesium layer after several times of rolling.

[0014] Further, the interface intermetallic compound layer is composed of Mg 17 Al 12 , and Al3Mg2.

[0015] Further, the thickness of the interface intermetallic compound layer is 5-15 μm.

[0016] Compared with the prior art, the beneficial effects achieved by the present application are: the present application adopts a gradient structure design (GARB), and through a specific non-symmetrical stacking cycle, the HARB N composite plate is always stacked above the HARB N-1 composite plate for stacking and rolling. Since the HARB N plate is further rolled after being bisected from the HARB N-1 plate (the reduction is 40-60%), the spacing between the layers of the HARB N plate is about 40-60% of the HARB N-1 plate. In the finish rolling process, the folding and placing of the HARB N-1 composite plate is to place the Mg-Li layer in the core for rolling, so that the layer thickness and the layer spacing of the composite material present a gradient change from the surface to the core, which is different from the uniform structure of the traditional symmetrical stacking (HARB). This structure helps to optimize the stress distribution and inhibit crack propagation.

[0017] The present application realizes effective control of the discontinuous intermetallic compound interface by synergistically controlling the preheating temperature (300-400℃) and large single-pass reduction (40-60%), mechanically breaking the intermetallic compound layer formed between passes by large shear deformation force, and maintaining the discontinuous block morphology in the subsequent "breakage-diffusion-rebreakage" cycle, rather than the harmful continuous layer. BRIEF DESCRIPTION OF DRAWINGS

[0018] The accompanying drawings are included to provide a further understanding of the present application, and are incorporated in and constitute a part of the specification, illustrate embodiments of the present application and explain the present application, and do not constitute a limitation of the present application. In the drawings: Figure 1 X-ray diffraction spectrum of the composite plate in the present application examples 1-3; Figure 2 Scanning electron micrograph of the composite plate in the present application examples 1-3; Figure 3 Backscattered electron image and EDS line scan results of the composite plate in the present application examples 1-3.

[0019] Figure 4 Preparation flowchart of high-performance magnesium-aluminum layered composite plate material in the present application. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0021] Materials and sources used in the present application: The magnesium-lithium alloy used in the present application is prepared by laboratory smelting. The magnesium-lithium alloy has the following components by mass fraction: Li: 8%; Zn: 6%; Y: 1.2%, and the balance is Mg. The pure aluminum plate used in the embodiments of the present application is a 1060 brand industrial pure aluminum plate provided by Shenzhen Deli Machinery Hardware Co., Ltd.

[0022] Example 1: A preparation method of a high-performance magnesium-aluminum layered composite plate, comprising the following steps: Step 1: S11: Cut the magnesium-lithium alloy plate and the pure aluminum plate into samples with the same length and width size (35mm x 60mm) and different thicknesses, wherein the thickness ratio of the aluminum plate to the magnesium-lithium alloy plate is 0.01:1; use a steel ball to polish the bonding surface to remove the oxide layer and obtain a fresh metal surface; S12: After the processed samples are stacked in the order of "Al / Mg-Li", four holes are drilled, and then aluminum wires are used for fixation to prevent relative sliding during rolling; Step 2: S21: After the fixed plate blank is kept in a holding furnace with an argon atmosphere at 300°C for 10 min, it is sent to a rolling mill, and the plate is rolled at a reduction of 40% to complete the first pass to achieve initial bonding, with a rolling speed of 3 rad / min; a composite plate HARB0 is prepared; S22: The composite plate HARB0 is cut into two equal parts, and after surface polishing treatment, it is stacked and fixed in the order of Al / Mg-Li / Al / Mg-Li, and then sent to the rolling mill after being kept at 300°C for 10 min; the plate is rolled at a reduction of 40% to complete the pass, and a composite plate HARB1 is prepared; S23: After the composite plate HARB0 and the composite plate HARB1 are cut to have the same length and width dimensions, they are stacked in the order of HARB1 / HARB0, and then rolled; the prepared plate is folded and placed, and the Mg-Li layer in the HARB0 plate is placed in the core for final rolling; after final rolling, the prepared plate is denoted as GARB1.

[0023] In this embodiment, a gradient heterogeneous layered plate containing 11 Mg-Li / Al heterogeneous layers and 10 heterogeneous interfaces is prepared.

[0024] Embodiment 2: A method for preparing a high-performance magnesium-aluminum layered composite plate, comprising the following steps: Step 1: S11: Magnesium-lithium alloy plates and pure aluminum plates are cut into samples with the same length and width dimensions (35 mm x 60 mm) and different thicknesses, and the thickness ratio of the aluminum plate to the magnesium-lithium alloy plate is 0.05:1; a steel ball is used to polish the bonding surface to remove the oxide layer and obtain a fresh metal surface; S12: After the processed samples are stacked in the order of "Al / Mg-Li", four holes are drilled, and then aluminum wires are used for fixation to prevent relative sliding during rolling; Step 2: S21: After the fixed plate blank is kept in a holding furnace with an argon atmosphere at 350°C for 15 min, it is sent to a rolling mill, and the plate is rolled at a reduction of 50% to complete the first pass to achieve initial bonding, with a rolling speed of 5 rad / min; a composite plate HARB0 is prepared; S22: The composite plate HARB 0 is cut into two equal parts, and after surface polishing treatment again, it is stacked and fixed in the order of Al / Mg-Li / Al / Mg-Li, and after 15 min of heat preservation at 350°C, it is sent to the rolling mill. The plate is rolled with a reduction of 50% to complete the pass, and the composite plate HARB 1 is prepared; the composite plate HARB 1 is cut into two equal parts in the same way, and after surface polishing treatment again, it is stacked and rolled again in the same way of stacking, heat preservation temperature, time, and reduction, and the composite plate HARB 2 is prepared; S23: The composite plate HARB 1 and the composite plate HARB 2 are cut to have the same length and width, and then stacked in the order of HARB 2 / HARB 1 and rolled, and the prepared plate is folded and placed, and the Mg-Li layer in the HARB 1 plate is placed in the core for finish rolling; after finish rolling, the prepared plate is denoted as GARB 2.

[0025] In this embodiment, a gradient heterogeneous layered plate containing 23 Mg-Li / Al heterogeneous layers and 22 heterogeneous interfaces is prepared.

[0026] Example 3: A method for preparing a high-performance magnesium-aluminum layered composite plate, comprising the following steps: Step 1: S11: The magnesium-lithium alloy plate and the pure aluminum plate are cut into samples with the same length and width (35 mm x 60 mm) and different thicknesses, and the thickness ratio of the aluminum plate to the magnesium-lithium alloy plate is 0.1:1; steel balls are used to polish the bonding surface to remove the oxide layer and obtain a fresh metal surface; S12: The treated samples are stacked in the order of "Al / Mg-Li", and then fixed with aluminum wire around the hole to prevent relative sliding during rolling; Step 2: S21: The fixed plate blank is sent to the rolling mill after heat preservation at 400°C for 20 min in an argon atmosphere, and the plate is rolled with a reduction of 60% to complete the first pass to achieve initial bonding, and the rolling speed is 6 rad / min; the composite plate HARB 0 is prepared; S22: The composite plate HARB 0 is cut into two equal parts, and after surface grinding treatment again, it is stacked and fixed in the order of Al / Mg-Li / Al / Mg-Li, and after 20 min of heat preservation at 400 DEG C, it is sent to the rolling mill, and the plate is rolled with a reduction of 60%, to obtain the composite plate HARB 1; the composite plate HARB 1 is cut into two equal parts in the same way, and after surface grinding treatment again, it is stacked and rolled again in the same way, and the composite plate HARB 2 is obtained; the composite plate HARB 2 is cut into two equal parts in the same way, and after surface grinding treatment, it is stacked and rolled again in the same way to obtain the composite plate HARB 3; S23: The composite plate HARB 2 and the composite plate HARB 3 are cut to make their length and width dimensions consistent, and then stacked in the order of HARB 3 / HARB 2 and rolled, and the obtained plate is folded to make the Mg-Li layer in the HARB 2 plate in the core, and then finish rolling; after finish rolling, the obtained plate is denoted as GARB 3.

[0027] In this embodiment, a gradient heterogeneous layered plate containing 47 Mg-Li / Al heterogeneous layers and 46 heterogeneous interfaces is prepared.

[0028] Experiment: The high-performance magnesium-aluminum layered composite plates prepared in Examples 1-3 are tested by X-ray diffraction spectrum, scanning electron microscope image, backscattered electron image and EDS line scanning results.

[0029] For Example 1, the xrd detection spectrum is as shown in Figure 1 It can be seen that the main components of the intermetallic compound of the plate are Mg 17 Al 12 and Al3Mg2, and the SEM is as shown in Figure 2 2(a) and 2(d); the EDS line scanning image is as shown in Figure 3 3(a), 3(b), 3(c); from the figure, it can be seen that the thickness of the core magnesium-lithium alloy is obviously higher than that of the surface layer, the cross section of the plate shows a gradient thickness distribution, there is no obvious gap at the bonding layer, the interfacial intermetallic compound is discontinuously distributed in the form of blocks, the thickness is about 10.77 μm, the bonding condition is good, and no obvious defects are found.

[0030] For Example 2, the xrd detection spectrum is as shown in Figure 1 It can be seen that the main components of the intermetallic compound of the plate are Mg 17 Al 12 and Al3Mg2, and the SEM is as shown in Figure 2 2(b) and 2(e); the EDS line scanning image is as shown in Figure 3As shown in Figures 3(d), 3(e), and 3(f), it can be seen from the figures that the thickness of the magnesium-lithium alloy in the core is significantly higher than that of the surface layer. The cross-section of the plate shows a gradient thickness distribution, there are no obvious gaps at the bonding layer, and the intermetallic compound at the interface is distributed in a discontinuous blocky shape with a thickness of approximately 13.14 μm. The bonding is good, and no obvious defects are observed.

[0031] For Example 3, its XRD detection spectrum is as follows: Figure 1 It can be seen that the main component of the intermetallic compound in the sheet metal is Mg. 17 Al 12 And Al3Mg2, its SEM is as follows Figure 2 As shown in Figures 2(c) and 2(f); EDS line scan diagrams are as follows. Figure 3 Figures 3(g), 3(h), and 3(i) show that the core magnesium-lithium alloy is significantly thicker than the surface layer, and the plate cross-section exhibits a gradient thickness distribution. There are no obvious gaps at the bonding layer, and the intermetallic compound at the interface is distributed in a discontinuous blocky pattern with a thickness of approximately 11.12 μm. The bonding is good, and no obvious defects are observed.

[0032] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0033] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing high performance magnesium-aluminum layered composite board material, characterized by: The method comprises the following steps: Step 1: S11: cutting and polishing the magnesium-lithium alloy plate and the pure aluminum or aluminum alloy plate, for standby; S12: stacking the alloy plates with polished surfaces in the order of "Al / Mg-Li" to obtain a laminated plate; Step 2: S21: rolling the laminated plate for the first pass to obtain a composite plate, denoted as HARB 0; S22: cutting the composite plate HARB 0 into two equal parts, polishing the surfaces again, stacking and fixing in the order of Al / Mg-Li / Al / Mg-Li, and rolling under the same process conditions as in S21 to obtain a composite plate HARB 1; in turn, the above method is repeated for a positive integer N times of stacking, the composite plate HARB N-1 is cut into two equal parts, and the composite plate HARB N is prepared according to the above method; S23: cutting the composite plate HARB N-1 in S22 and the composite plate HARB N plate to make the length and width dimensions consistent, then stacking, and rolling under the same process conditions as in S21, folding the obtained plate and placing it to complete the final rolling, denoted as GARB N.

2. The method for preparing high-performance Mg-Al layered composite board material according to claim 1, characterized in that: In S11, the thickness ratio of the aluminum plate to the magnesium-lithium alloy plate is (0.01~0.1):

1.

3. The method for preparing high-performance Mg-Al layered composite board material according to claim 1, characterized in that: In S21, the specific method of the first pass rolling is: preheating the laminated plate to 300~400℃, keeping it in an argon atmosphere for 10~20min, the pass reduction is 40~60%, and the rolling speed is 3~6rad / min.

4. The method for preparing high-performance Mg-Al layered composite board material according to claim 1, characterized in that: In S23, the HARB N plate is always stacked above the HARB N-1 plate.

5. The method for preparing high-performance Mg-Al layered composite board material according to claim 1, characterized in that: In S23, when folding and placing, the Mg-Li layer in the HARB N-1 plate is placed in the core before final rolling.

6. The high-performance magnesium-aluminum layered composite plate material prepared by the method according to any one of claims 1~5.

7. The high performance magnesium-aluminum layered composite board material according to claim 6, characterized in that: The high-performance Mg-Al layered composite board material comprises 6x2 N -1 Mg-Li / Al heterolayer and 6x2 N -2 heterointerfaces.

8. The high-performance magnesium-aluminum layered composite board material according to claim 7, characterized in that: The heterogeneous interface is an intermetallic compound layer formed by the aluminum layer and the magnesium layer after several times of rolling.

9. The high-performance magnesium-aluminum layered composite board material according to claim 8, characterized in that: The interfacial intermetallic compound layer consists of Mg 17 Al 12 and Al3Mg2.

10. The high-performance magnesium-aluminum layered composite board material according to claim 8, characterized in that: The thickness of the intermetallic compound layer is 5~15μm.

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