A method for producing a layered composite material and a layered composite material

Abstract

The application provides a preparation method of a laminated composite material and the laminated composite material, and belongs to the technical field of composite materials, and comprises the following steps: stacking an annealed first plate, a second plate and a third plate to form a minimum unit, the second plate is located between the first plate and the third plate; the tensile strength of the second plate is 150-300 MPa; the thickness ratio of the first plate, the second plate and the third plate satisfies 20:(1-2):(10-15), and the thickness of the second plate is 0.05-0.80 mm; the minimum unit is rolled, and the reduction of the first pass rolling is 50%-75%. High-conductivity copper is introduced as an intermediate layer, through the crystal structure, the tensile strength of the second plate, the thickness ratio of the first plate to the third plate, and in combination with the subsequent rolling process, the first plate, the second plate and the third plate realize the matching of strength and plasticity, and the interface appears a deep corrugated structure.

Description

Technical Field

[0001] This invention belongs to the field of composite material technology, and specifically relates to a method for preparing layered composite materials and the layered composite material itself. Background Technology

[0002] The rapid development of fields such as deep space exploration, green transportation, and intelligent manufacturing has created new and urgent demands for novel integrated structural and functional materials. For lightweight metallic structural materials, new requirements are being placed on corrosion resistance, electromagnetic shielding, and radiation resistance, while ensuring mechanical properties. However, a single metal cannot meet these requirements. Therefore, combining different metallic materials to leverage their respective advantages and achieve complementary structural and functional properties is an important direction in current materials development.

[0003] Magnesium is the lightest metallic structural material. To meet the requirements of radiation resistance, electromagnetic shielding, corrosion resistance, and high conductivity, heavy metals such as tantalum, niobium, and tungsten, which have excellent corrosion resistance, radiation resistance, and electromagnetic shielding, are combined with magnesium. This enables the expansion of applications for high-energy particle radiation resistance and electromagnetic shielding in fields such as deep space exploration and green transportation, while significantly reducing the launch cost of detectors and improving the service life of devices. Research on electromagnetic shielding composite material systems shows that Mg / Ta composite materials have excellent electromagnetic shielding effects and can significantly reduce the overall weight of shielding devices (Wang Jianzhao, Ma Jinan, Zhang Qingxiang, et al. Radiation shielding optimization design method of multilayer materials in Jupiter system exploration [J]. Spacecraft Environmental Engineering, 2019, 36(6).).

[0004] Chinese invention patents with publication numbers CN115742485A and CN115740002A disclose a magnesium-tantalum metal composite method based on Al as the intermediate layer. However, the process involves the use of aluminum plates with B4C ceramic particles on the surface, deep cryogenic treatment of the plates by immersion in liquid nitrogen, and high-temperature diffusion annealing. The overall process is relatively complex. Furthermore, due to the introduction of the Al layer, Mg is generated at the Mg / Al interface during hot working and high-temperature diffusion annealing. 17 Al 12 The risk of brittle intermetallic compounds such as Mg2Al3 poses a potential threat to the performance stability of composite plates. Summary of the Invention

[0005] To address the shortcomings of the existing technology, this invention provides a method for preparing a layered composite material and the layered composite material itself. It innovatively introduces highly conductive copper as an intermediate layer and optimizes the interface control process to form a multi-layered heterogeneous interface. This interface effectively scatters and dissipates electromagnetic waves, achieving superior electromagnetic shielding performance. Furthermore, it possesses the excellent radiation resistance inherent in tantalum metal, thus greatly expanding the protective coverage of magnesium-based alloys. Simultaneously, it exhibits superior conductivity compared to conventional magnesium alloys, and the strong plasticity matching of the first, second, and third plates improves the interfacial bonding strength.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] On one hand, the present invention provides a method for preparing a layered composite material, comprising the following steps: stacking annealed first, second, and third plates to form a minimum unit, wherein the first plate has an HCP structure, the second plate has an FCC structure, and the third plate has a BCC structure, with the second plate located between the first and third plates; the tensile strength of the second plate is 150-300 MPa; the thickness ratio of the first, second, and third plates satisfies 20:(1-2):(10-15), and the thickness of the second plate is 0.05-0.80 mm; rolling the minimum unit, wherein the reduction in the first rolling pass is 50%-75%.

[0008] Furthermore, the smallest unit is preheated before rolling by wrapping it with aluminum foil, and the holding temperature is 150-350℃ for 15-35 minutes.

[0009] Furthermore, the first plate is one or more of AZ31, AZ91, ZK60 / 61, and Mg-RE series alloy plates; and / or, the second plate is one or more of copper or copper alloys; and / or, the third plate is tantalum.

[0010] Furthermore, the smallest unit is arranged using a first plate | second plate | third plate | second plate | first plate.

[0011] Furthermore, the minimum unit is rolled in subsequent passes no more than twice, and the reduction in each pass is 10%-20%; the minimum units after the first pass rolling are stacked and then rolled in layers, and the stacking and rolling are repeated no more than five times, and the reduction in the rolling is 50%-65%.

[0012] Furthermore, the smallest units after the first rolling pass are stacked at 90° and then subjected to stacking rolling. The stacking and rolling are repeated no more than five times, and each time they are stacked at 90°. The stacking reduction is 55%-65%.

[0013] Furthermore, the rolling speed of the first rolling pass, subsequent rolling passes, and stacking rolling is 0.015-0.05 m / s, and the roll temperature is 150-350℃.

[0014] Furthermore, before the stacking process, the surface of the composite material in the first rolling or the previous stacking is polished, and then it is heated in a vacuum environment or inert gas atmosphere at a temperature of 300-350℃ for a holding time of 10-20 minutes.

[0015] Furthermore, the first and third plates after annealing are polished, including rolling and transverse polishing, and the transverse and longitudinal surface roughness Ra after polishing is 5-15μm.

[0016] The present invention also provides a layered composite material, which is prepared by the above-described preparation method.

[0017] Compared with the prior art, the technical solution provided by the present invention brings the following beneficial effects:

[0018] This application, through the analysis of the crystal structure of the material, the tensile strength of the second plate, the thickness ratio of the first to the third plate, and the subsequent rolling process, enables the first and third plates, which have significant differences in structure and physicochemical properties and are difficult to directly form an atomic interdiffusion interface, to achieve strong plastic matching by introducing the second plate. This results in a strongly bonded endogenous deep corrugated structure interface. Macroscopically, the interfaces are interlocked with high mechanical bonding strength. Microscopically, the interfaces exhibit mutual embedding or interlocking, achieving cross-scale mechanical interlocking and resulting in high mechanical bonding strength. This interface is the optimal result sought in the preparation of layered composite materials through rolling methods. In particular, the microscopic interlocked interface is the main reason for the high interfacial bonding strength under varying temperatures and the low susceptibility to cracking. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a SEM image of the layered composite material prepared in Example 1 of the present invention;

[0021] Figure 2 This is a SEM image of the layered composite material prepared in Example 5 of the present invention;

[0022] Figure 3A macroscopic view of the layered composite material prepared in Comparative Example 1;

[0023] Figure 4 The phase diagrams for the layered composite materials prepared in Comparative Example 2 are shown in Figure a, where a is the macroscopic morphology diagram and b is the microscopic morphology diagram. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The specific embodiments of this invention are not limited to those given herein, and those skilled in the art can make similar improvements without departing from the spirit of this invention. Therefore, this invention is not limited to the disclosed specific embodiments.

[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used is for describing particular embodiments only and does not limit the scope of the invention.

[0026] This invention provides a method for preparing a layered composite material, comprising the following steps:

[0027] S1 stacks the annealed first, second, and third plates to form the smallest unit. The first plate has an HCP structure, the second plate has an FCC structure, and the third plate has a BCC structure. The second plate is located between the first and third plates. The tensile strength of the second plate is 150-300 MPa. The thickness ratio of the first, second, and third plates satisfies 20:(1-2):(10-15), and the thickness of the second plate is 0.05-0.80 mm.

[0028] S2 rolls the smallest unit, and the reduction in the first rolling pass is 50%-75%.

[0029] This application achieves a strong-plastic match between the first, second, and third plates by optimizing the crystal structure of the material, the tensile strength of the second plate, the thickness ratio of the first to third plates, and combining these with subsequent rolling processes. This results in a deep wavy structure at the interface, meaning that from a macroscopic perspective, the interfaces are interlocked and exhibit high mechanical bonding strength. From a microscopic perspective, the interfaces also exhibit interlocking and high mechanical bonding strength. This interface is the optimal result sought in preparing layered composite materials through rolling methods. Firstly, the HCP crystal form has only four independent slip systems, making multi-directional slip difficult and resulting in poor plastic deformation capacity. The BCC crystal, on the other hand, has 48 independent slip systems, making multi-directional slip easy and thus exhibiting high plastic deformation capacity. Consequently, during rolling, these two crystal forms have poor strength-plasticity matching. Without the formation of an atomic diffusion interface, even under large deformation conditions, a deep corrugated structure cannot form at the interface. This is because the BCC crystal is easily deformed during deformation and cannot be kneaded with the difficult-to-process HCP crystal form to form a deep corrugated structure, resulting in low bonding strength and low interlaminar tear resistance. Typically, both metallurgical and mechanical bonding are required to achieve an engineerable layered composite material. However, this application... It is only possible to achieve a deep corrugated structure at the interface between the first and second plates, and between the second and third plates, by adding a second plate of the FCC crystal form between the first plate and the third plate of the BCC crystal form. To generate a deep corrugated structure at the interface, it is necessary to consider the rolling process, thickness setting, and the strength of the second plate, which work together to achieve a deep corrugated structure. This structure makes the deformation of the composite material more coordinated, and the atomic diffusion at the interface is more sufficient. The thickness of the second plate affects the stress state and atomic diffusion at the interface during the rolling process. If the second plate is too thick, under a large reduction, the deformation will be uncoordinated and the atomic diffusion will be insufficient, which may lead to interface tearing. If the second plate is too thin, the first plate may puncture the second plate, resulting in a decrease in interlayer bonding strength and conductivity.

[0030] It should be noted that the smallest unit in this application can be a structure of first plate | second plate | third plate. Although the difference in materials on both sides during the rolling process can cause bending deformation of the rolled composite material, it does not affect the formation of a deep corrugated structure at the interface between the first plate and the second plate, as well as between the second plate and the third plate. The annealing process for the first plate, second plate, and third plate in this application can be based on the actual material selection, setting the corresponding annealing temperature and holding time. This technology is common knowledge and can be obtained from existing literature.

[0031] The smallest unit is preheated before rolling, and is covered with aluminum foil. The holding temperature is 150-350℃, and the holding time is 15-35 minutes. Preheating before rolling reduces rolling stress and increases the fluidity of the metal. Covering with aluminum foil prevents oxidation of the stacked plates.

[0032] The first plate is one or more of AZ31, AZ91, ZK60 / 61, and Mg-RE series alloy plates; and / or, the second plate is one or more of copper or copper alloys; and / or, the third plate is tantalum. It should be noted that the first plate is a known material and is not the inventive point of this invention; the copper and copper alloys are existing materials, but their strength and crystal form need to meet the limitations of this application; the third plate is a pure tantalum plate to improve radiation resistance.

[0033] The smallest unit is arranged in a first plate | second plate | third plate | second plate | first plate arrangement. This symmetrical arrangement can reduce or eliminate deformation curling caused by inconsistent deformation on both sides of the composite material during rolling. The first plates can be made of the same or different materials, such as all first plates being AZ31 (AZ31|Cu|Ta|Cu|AZ31), or the first plates being AZ31 and AZ91 respectively (AZ31|Cu|Ta|Cu|AZ91).

[0034] After rolling the minimum unit, rolling continues to prepare a high-performance layered composite material, but the number of layers is 5. Subsequent rolling passes for the minimum unit do not exceed two, and the reduction per pass is 10%-20%. On the other hand, the minimum units rolled in the first pass are stacked and then subjected to stacking and rolling, repeated no more than five times. The reduction in the stacking and rolling is 50%-65%, to increase the number of layers in the prepared layered composite material and improve its radiation resistance. Specifically, the first stacking and rolling involves stacking the minimum units, resulting in 10 layers; the second stacking and rolling involves continuing stacking and rolling, resulting in 20 layers; and the third stacking and rolling involves continuing stacking and rolling, resulting in 40 layers. Through subsequent rolling passes and stacking, the probability of generating a micro-wave structure is further increased. The micro-wave structure generated by subsequent rolling passes can improve tear resistance by at least 10%. However, the number of subsequent rolling passes, the amount of reduction per pass, and the number of stacking and rolling passes need to be strictly controlled. While improving the tear resistance of the layered composite material, it is necessary to avoid over-rolling which can lead to internal cracks, or too few rolling passes and too little reduction which can prevent the effective formation of the micro-wave structure, resulting in low bonding strength.

[0035] In a preferred embodiment, the smallest units after the first rolling pass are stacked at 90° and then rolled again. This stacking is repeated no more than five times, with each stack at 90°. The rolling reduction is 55%-65%. Compared to other stacking methods, using 90° stacking results in a richer micro-wave structure, thereby increasing the tear resistance by at least 5%.

[0036] The rolling speed for the first rolling pass, subsequent rolling passes, and stacking rolling is 0.015-0.05 m / s, and the roll temperature is 150-350℃. The rolling speed is related to the rate of heat generation during rolling. Strict control of the rolling speed and roll temperature ensures that the mechanical bonding strength between the interfaces of the layered composite material reaches the optimal level during rolling, preventing excessively high local temperatures that would reduce the formation of micro-wave-like structures, and preventing excessively low local temperatures that would reduce deformation capacity.

[0037] Furthermore, before the lamination process, the surface of the composite material from the first rolling pass or the previous lamination pass is polished, followed by heat treatment in a vacuum environment or inert gas atmosphere at a temperature of 300-350℃ for 10-20 minutes. This reduces oxides on the surface of the composite material and improves the mechanical bonding strength of the interface to be bonded after lamination.

[0038] The annealed first and third plates are polished, including rolling-direction and transverse polishing, resulting in a transverse and longitudinal surface roughness Ra of 5-15 μm. Although this invention can utilize the crystal form, strength, thickness, and rolling process between the plates to prepare a bonding interface with a deep corrugated structure, increasing the surface roughness can improve the macroscopic contact area of ​​the plate interface and enhance the interlayer bonding strength of the layered composite material. However, the second plate is relatively thin, and the probability of breakage or tearing during rolling is relatively high, leading to a significant reduction in the bonding strength between the first and second plates. Therefore, the surface roughness of the first and second plates is limited. The surface roughness should not be too small, as this would result in an insignificant strengthening effect and affect the formation of the micro-corrugated structure. Conversely, the roughness should not be too large, as this would increase the probability of breakage and tearing.

[0039] Preferably, the first rolling pass, subsequent rolling passes, and stacking are performed in a vacuum or inert gas atmosphere.

[0040] This invention also provides a layered composite material, which is prepared by the above-described preparation method.

[0041] Since the layered composite material prepared in this application is intended for use in deep space environments, high-radiation environments, and environments with drastic temperature fluctuations, the testing content includes:

[0042] DSC test: Heat from room temperature to 500℃ at a rate of 20℃ / s, hold for 1 hour, and check for cracks at the magnesium-copper-tantalum interface.

[0043] Mechanical property testing: The yield strength and tensile strength of the sheet are tested according to national standards.

[0044] Interfacial bond strength: The minimum tensile force required to tear a layered composite material is defined as the interfacial bond strength.

[0045] Conductivity test: The conductivity was tested according to national standards. The longitudinal sample of the prepared layered composite material was taken and tested by applying electricity to both ends.

[0046] To further illustrate the present invention, the following detailed description is provided in conjunction with embodiments, but these should not be construed as limiting the scope of protection of the present invention.

[0047] Example 1

[0048] This invention provides a method for preparing a layered composite material and the layered composite material itself. The preparation method includes:

[0049] S1 stacks the annealed AZ31B plate (first plate), Cu foil (second plate), and Ta plate (third plate) to form the smallest unit, with the Cu foil located between the AZ31B plate and the Ta plate; the tensile strength of the Cu foil is 220 MPa; the thickness of the AZ31B plate is 1 mm, the thickness of the Cu foil is 0.1 mm, and the thickness of the Ta plate is 0.5 mm.

[0050] The surfaces of AZ31B and Ta plates were polished along the rolling direction and transverse direction respectively. The surface roughness Ra of the transverse and longitudinal directions after polishing was 5-15μm. After polishing, the Ta plate, AZ31B plate and Cu foil were cleaned with anhydrous ethanol and then vacuum dried.

[0051] The pretreated plates were stacked in the order of AZ31B|Cu|Ta|Cu|AZ31B, and the edges were fixed by welding or rivets. Then they were placed in a heating furnace and kept at 350°C for 30 minutes.

[0052] S2 stacks the preheated AZ31B|Cu|Ta|Cu|AZ31B, and the first rolling pass has a reduction of 65%, a roll temperature of 280℃, and a rolling speed of 0.02m / s.

[0053] First stacking: The smallest unit after the first rolling pass is surface treated with an angle grinder to remove the oxide layer and impurity layer. Then, it is cut into two pieces of equal length from 1 / 2 of the smallest unit. The two pieces of plate are stacked and fixed with electric welding or rivets. Then, they are placed in a heating furnace for heat preservation at 350℃ for 15 minutes. The above plates are then stacked and rolled at a roll temperature of 280℃, a reduction of 50%, and a rolling speed of 0.02m / s.

[0054] Second rolling: The composite material after the first rolling is surface treated with an angle grinder to remove the oxide layer and impurity layer. Then, it is cut into two pieces of equal length from 1 / 2 of the composite material. The two pieces of composite material are stacked and fixed with electric welding or rivets. Then, they are placed in a heating furnace for heat preservation at 350℃ for 15 minutes. The above plates are then rolled with a roll temperature of 280℃, a reduction of 50%, and a rolling speed of 0.02m / s.

[0055] Finally, the surface of the rolled sheet was treated with an angle grinder to remove the oxide layer and impurity layer, and a layered composite sheet with the smallest unit being AZ31B|Cu|Ta|Cu|AZ31B was obtained, containing a total of 20 layers of magnesium, copper and tantalum.

[0056] DSC testing showed that when the prepared layered composite board was heated from room temperature to 500℃ and held at that temperature for 1 hour, no cracks appeared at the magnesium-copper-tantalum interface. Figure 1 As shown.

[0057] Mechanical properties, electrical conductivity, and thermodynamics of the above-mentioned sheet were tested. The results showed that the tensile yield strength of the prepared sheet was 343.17 MPa, the tensile strength was 377.98 MPa, the elongation was 6.5%, the interfacial bond strength was 65 MPa, and the room temperature electrical conductivity was 28 ± 3 KS / mm.

[0058] Example 2

[0059] This invention provides a method for preparing a layered composite material and the layered composite material itself. The preparation method includes:

[0060] S1 stacks the annealed AZ31B plate (first plate), Cu foil (second plate), and Ta plate (third plate) to form the smallest unit, with the Cu foil located between the AZ31B plate and the Ta plate; the tensile strength of the Cu foil is 220 MPa; the thickness of the AZ31B plate is 1 mm, the thickness of the Cu foil is 0.05 mm, and the thickness of the Ta plate is 0.7 mm.

[0061] The surfaces of AZ31B and Ta plates were polished along the rolling direction and transverse direction respectively. The surface roughness Ra of the transverse and longitudinal directions after polishing was 5-15μm. After polishing, the Ta plate, AZ31B plate and Cu foil were cleaned with anhydrous ethanol and then vacuum dried.

[0062] The pretreated plates were stacked in the order of AZ31B|Cu|Ta|Cu|AZ31B, and the edges were fixed by welding or rivets. Then they were placed in a heating furnace and kept at 350°C for 30 minutes.

[0063] S2 stacks the preheated AZ31B|Cu|Ta|Cu|AZ31B, and the first rolling pass has a reduction of 60%, a roll temperature of 150℃, and a rolling speed of 0.02m / s.

[0064] First stacking: The smallest unit after the first rolling pass is surface treated with an angle grinder to remove the oxide layer and impurity layer. Then, it is cut into two pieces of equal length from 1 / 2 of the smallest unit. The two pieces of plate are stacked and fixed with electric welding or rivets. Then, they are placed in a heating furnace for heat preservation at 350℃ for 20 minutes. The above plates are then stacked and rolled at 150℃ with a roll temperature of 50% and a rolling speed of 0.02m / s.

[0065] Second rolling: The composite material after the first rolling is surface treated with an angle grinder to remove the oxide layer and impurity layer. Then, it is cut into two pieces of equal length from 1 / 2 of the composite material. The two pieces of composite material are stacked and fixed with electric welding or rivets. Then, they are placed in a heating furnace for heat preservation at 350°C for 15 minutes. The above plates are then rolled with a roll temperature of 150°C, a reduction of 50%, and a rolling speed of 0.02m / s.

[0066] Finally, the surface of the rolled sheet was treated with an angle grinder to remove the oxide layer and impurity layer, and a layered composite sheet with the smallest unit being AZ31B|Cu|Ta|Cu|AZ31B was obtained, containing a total of 20 layers of magnesium, copper and tantalum.

[0067] DSC testing showed that the magnesium-copper-tantalum interface did not crack when heated from room temperature to 500℃. The prepared plate had a tensile yield strength of 301.4 MPa, a tensile strength of 340.31 MPa, and an elongation of 6%; the interfacial bond strength was 56 MPa, and the room temperature conductivity was 28 ± 3 KS / mm.

[0068] Example 3

[0069] This invention provides a method for preparing a layered composite material and the layered composite material itself. The preparation method includes:

[0070] S1 stacks the annealed AZ31B plate (first plate), Cu foil (second plate), and Ta plate (third plate) to form the smallest unit, with the Cu foil located between the AZ31B plate and the Ta plate; the tensile strength of the Cu foil is 220 MPa; the thickness of the AZ31B plate is 10 mm, the thickness of the Cu foil is 0.5 mm, and the thickness of the Ta plate is 7.5 mm.

[0071] The surfaces of AZ31B and Ta plates were polished along the rolling direction and transverse direction respectively. The surface roughness Ra of the transverse and longitudinal directions after polishing was 5-15μm. After polishing, the Ta plate, AZ31B plate and Cu foil were cleaned with anhydrous ethanol and then vacuum dried.

[0072] The pretreated plates were stacked in the order of AZ31B|Cu|Ta|Cu|AZ31B, and the edges were fixed by welding or rivets. Then they were placed in a heating furnace and kept at 150°C for 35 minutes.

[0073] S2 stacks the preheated AZ31B|Cu|Ta|Cu|AZ31B, and the first rolling pass has a reduction of 60%, a roll temperature of 150℃, and a rolling speed of 0.015m / s.

[0074] First stacking: The smallest unit after the first rolling pass is surface treated with an angle grinder to remove the oxide layer and impurity layer. Then, it is cut into two pieces of equal length from 1 / 2 of the smallest unit. The two pieces of plate are stacked and fixed with electric welding or rivets. Then, they are placed in a heating furnace for heat preservation at 350℃ for 20 minutes. The above plates are then stacked and rolled at 150℃ with a roll temperature of 50% and a rolling speed of 0.015m / s.

[0075] Finally, the rolled sheet was surface-treated with an angle grinder to remove the oxide layer and impurity layer, and a layered composite sheet with the smallest unit being AZ31B|Cu|Ta|Cu|AZ31B was obtained, containing a total of 10 layers of magnesium, copper and tantalum.

[0076] DSC testing showed that the magnesium-copper-tantalum interface did not crack when heated from room temperature to 500℃. The prepared plate had a tensile yield strength of 178.5 MPa, a tensile strength of 280 MPa, and an elongation of 6%; the interfacial bond strength was 51 MPa, and the room temperature conductivity was 31 ± 2 KS / mm.

[0077] Example 4

[0078] This invention provides a method for preparing a layered composite material and the layered composite material itself. The preparation method includes:

[0079] S1 stacks the annealed AZ31B plate (first plate), Cu foil (second plate), and Ta plate (third plate) to form the smallest unit, with the Cu foil located between the AZ31B plate and the Ta plate; the tensile strength of the Cu foil is 220 MPa; the thickness of the AZ31B plate is 2 mm, the thickness of the Cu foil is 0.1 mm, and the thickness of the Ta plate is 1 mm.

[0080] The surfaces of AZ31B and Ta plates were polished along the rolling direction and transverse direction respectively. The surface roughness Ra of the transverse and longitudinal directions after polishing was 5-15μm. After polishing, the Ta plate, AZ31B plate and Cu foil were cleaned with anhydrous ethanol and then vacuum dried.

[0081] The pretreated plates were stacked in the order of AZ31B|Cu|Ta|Cu|AZ31B, and the edges were fixed by welding or rivets. Then they were placed in a heating furnace and kept at 300℃ for 30 minutes.

[0082] S2 stacks the preheated AZ31B|Cu|Ta|Cu|AZ31B, and the first rolling pass has a reduction of 50%, a roll temperature of 300℃, and a rolling speed of 0.015m / s.

[0083] First stacking: The smallest unit after the first rolling pass is surface treated with an angle grinder to remove the oxide layer and impurity layer. Then, it is cut into two pieces of equal length from 1 / 2 of the smallest unit. The two pieces are stacked and fixed with electric welding or rivets. Then, they are placed in a heating furnace for heat preservation at 300℃ for 15 minutes. The above-mentioned pieces are then stacked and rolled at 300℃, with a reduction of 50% and a rolling speed of 0.05m / s.

[0084] Second rolling: The composite material after the first rolling is surface treated with an angle grinder to remove the oxide layer and impurity layer. Then, it is cut into two pieces of equal length from 1 / 2 of the composite material. The two pieces are stacked and fixed with electric welding or rivets. Then, they are placed in a heating furnace for heat preservation at 300℃ for 15 minutes. The above-mentioned pieces are then rolled with a roll temperature of 300℃, a reduction of 50%, and a rolling speed of 0.05m / s.

[0085] Third rolling: The composite material after the second rolling is surface treated with an angle grinder to remove the oxide layer and impurity layer. Then, it is cut into two pieces of equal length from 1 / 2 of the composite material. The two pieces are stacked and fixed with electric welding or rivets. Then, they are placed in a heating furnace for heat preservation at 300℃ for 15 minutes. The above-mentioned pieces are then rolled with a roll temperature of 300℃, a reduction of 50%, and a rolling speed of 0.05m / s.

[0086] Finally, the surface of the rolled sheet was treated with an angle grinder to remove the oxide layer and impurity layer, and a layered composite sheet with the smallest unit being AZ31B|Cu|Ta|Cu|AZ31B was obtained, containing a total of 40 layers of magnesium, copper and tantalum.

[0087] DSC testing showed that the magnesium-copper-tantalum interface did not crack when heated from room temperature to 500℃. The prepared plate had a tensile yield strength of 150MPa, a tensile strength of 280MPa, an elongation of 6%, an interfacial bond strength of 46.83MPa, and a room temperature conductivity of 26±2KS / mm.

[0088] Example 5

[0089] This invention provides a method for preparing a layered composite material and the layered composite material itself. The preparation method includes:

[0090] S1 stacks the annealed ZK61 plate (first plate), Cu foil (second plate), and Ta plate (third plate) to form the smallest unit, with the Cu foil located between the ZK61 plate and the Ta plate; the tensile strength of the Cu foil is 220 MPa; the thickness of the ZK61 plate is 10 mm, the thickness of the Cu foil is 0.8 mm, and the thickness of the Ta plate is 6 mm.

[0091] The surfaces of ZK61 and Ta plates were polished along the rolling direction and transverse direction respectively. The surface roughness Ra of the transverse and longitudinal directions after polishing was 5-15μm. After polishing, the Ta plate, ZK61 plate and Cu foil were cleaned with anhydrous ethanol and then vacuum dried.

[0092] The pretreated plates were stacked in the order of ZK61|Cu|Ta|Cu|ZK61, and the edges were fixed by welding or rivets. Then they were placed in a heating furnace and kept at 350°C for 15 minutes.

[0093] S2 stacks the preheated ZK61|Cu|Ta|Cu|ZK61, and the first rolling pass has a reduction of 60%, a roll temperature of 350℃, and a rolling speed of 0.02m / s.

[0094] First stacking: The smallest unit after the first rolling pass is surface treated with an angle grinder to remove the oxide layer and impurity layer. Then, it is cut into two pieces of equal length from 1 / 2 of the smallest unit. The two pieces are stacked and fixed with electric welding or rivets. Then, they are placed in a heating furnace for heat preservation at 350°C for 15 minutes. The above-mentioned pieces are then stacked and rolled at 350°C, with a reduction of 50% and a rolling speed of 0.02m / s.

[0095] Finally, the surface of the rolled plate was treated with an angle grinder to remove the oxide layer and impurity layer, and a layered composite plate with the smallest unit being ZK61|Cu|Ta|Cu|ZK61 was obtained, containing a total of 10 layers of magnesium, copper and tantalum.

[0096] DSC testing showed that the magnesium-copper-tantalum interface did not crack when heated from room temperature to 500℃. Figure 2 As shown. The prepared sheet has a tensile yield strength of 200 MPa, a tensile strength of 280 MPa, an elongation of 6%, an interfacial bond strength of 62 MPa, and a room temperature conductivity of 45 ± 3 KS / mm.

[0097] Example 6

[0098] This invention provides a method for preparing a layered composite material and the layered composite material itself. The preparation method includes:

[0099] S1 stacks the annealed ZK61 plate (first plate), Cu foil (second plate), and Ta plate (third plate) to form the smallest unit, with the Cu foil located between the ZK61 plate and the Ta plate; the tensile strength of the Cu foil is 220 MPa; the thickness of the ZK61 plate is 5 mm, the thickness of the Cu foil is 0.5 mm, and the thickness of the Ta plate is 3 mm.

[0100] The surfaces of ZK61 and Ta plates were polished along the rolling direction and transverse direction respectively. The surface roughness Ra of the transverse and longitudinal directions after polishing was 5-15μm. After polishing, the Ta plate, ZK61 plate and Cu foil were cleaned with anhydrous ethanol and then vacuum dried.

[0101] The pretreated plates were stacked in the order of ZK61|Cu|Ta|Cu|ZK61, and the edges were fixed by welding or rivets. Then they were placed in a heating furnace and kept at 300°C for 30 minutes.

[0102] S2 stacks the preheated ZK61|Cu|Ta|Cu|ZK61, and the first rolling pass has a reduction of 60%, a roll temperature of 250℃, and a rolling speed of 0.02m / s.

[0103] First stacking: The smallest unit after the first rolling pass is surface treated with an angle grinder to remove the oxide layer and impurity layer. Then, it is cut into two pieces of equal length from 1 / 2 of the smallest unit. The two pieces of plate are stacked and fixed with electric welding or rivets. Then, they are placed in a heating furnace for heat preservation at 250°C for 15 minutes. The above plates are then stacked and rolled at 250°C, with a reduction of 50% and a rolling speed of 0.02m / s.

[0104] Second rolling: The composite material after the first rolling is surface treated with an angle grinder to remove the oxide layer and impurity layer. Then, it is cut into two pieces of equal length from 1 / 2 of the composite material. The two pieces are stacked and fixed with electric welding or rivets. Then, they are placed in a heating furnace for heat preservation at 250°C for 15 minutes. The above-mentioned pieces are then rolled with a roll temperature of 250°C, a reduction of 50%, and a rolling speed of 0.02m / s.

[0105] Third rolling: The composite material after the second rolling is surface treated with an angle grinder to remove the oxide layer and impurity layer. Then, it is cut into two pieces of equal length from 1 / 2 of the composite material. The two pieces are stacked and fixed with electric welding or rivets. Then, they are placed in a heating furnace for heat preservation at 250°C for 15 minutes. The above-mentioned pieces are then rolled with a roll temperature of 250°C, a reduction of 50%, and a rolling speed of 0.02m / s.

[0106] Fourth rolling: The composite material after the third rolling is surface treated with an angle grinder to remove the oxide layer and impurity layer. Then, it is cut into two pieces of equal length from 1 / 2 of the composite material. The two pieces are stacked and fixed with electric welding or rivets. Then, they are placed in a heating furnace for heat preservation at 250°C for 15 minutes. The above-mentioned pieces are then rolled with a roll temperature of 250°C, a reduction of 50%, and a rolling speed of 0.02m / s.

[0107] Fifth rolling: The composite material after the fourth rolling is surface treated with an angle grinder to remove the oxide layer and impurity layer. Then, it is cut into two pieces of equal length from 1 / 2 of the composite material. The two pieces are stacked and fixed with electric welding or rivets. Then, they are placed in a heating furnace for heat preservation at 250°C for 15 minutes. The above-mentioned pieces are then rolled with a roll temperature of 250°C, a reduction of 50%, and a rolling speed of 0.02m / s.

[0108] Finally, the rolled sheet was surface-treated with an angle grinder to remove the oxide layer and impurity layer, and a layered composite sheet with the smallest unit being AZ31B|Cu|Ta|Cu|AZ31B was obtained, containing a total of 160 layers of magnesium, copper and tantalum.

[0109] DSC testing showed that the magnesium-copper-tantalum interface did not crack when heated from room temperature to 500℃. The prepared plate had a tensile yield strength of 200MPa, a tensile strength of 280MPa, an elongation of 6%, an interfacial bond strength of 46.83MPa, and a room temperature conductivity of 38±3KS / mm.

[0110] Example 7

[0111] This invention provides a method for preparing a layered composite material and the layered composite material itself. The preparation method includes:

[0112] S1 stacks the annealed AZ31B plate (first plate), Cu foil (second plate), and Ta plate (third plate) to form the smallest unit, with the Cu foil located between the AZ31B plate and the Ta plate; the tensile strength of the Cu foil is 220 MPa; the thickness of the AZ31B plate is 1 mm, the thickness of the Cu foil is 0.1 mm, and the thickness of the Ta plate is 0.5 mm.

[0113] The surfaces of AZ31B and Ta plates were polished along the rolling direction and transverse direction respectively. The surface roughness Ra of the transverse and longitudinal directions after polishing was 5-15μm. After polishing, the Ta plate, AZ31B plate and Cu foil were cleaned with anhydrous ethanol and then vacuum dried.

[0114] The pretreated plates were stacked in the order of AZ31B|Cu|Ta|Cu|AZ31B, and the edges were fixed by welding or rivets. Then they were placed in a heating furnace and kept at 350°C for 30 minutes.

[0115] S2 stacks the preheated AZ31B|Cu|Ta|Cu|AZ31B. The first rolling pass has a reduction of 50%, a roll temperature of 150℃, and a rolling speed of 0.015m / s. The second rolling pass has a reduction of 10%, a roll temperature of 150℃, and a rolling speed of 0.015m / s. The third rolling pass has a reduction of 10%, a roll temperature of 150℃, and a rolling speed of 0.015m / s.

[0116] Finally, the surface of the rolled sheet is treated with an angle grinder to remove the oxide layer and impurity layer, and a layered composite sheet with the smallest unit being AZ31B|Cu|Ta|Cu|AZ31B is obtained.

[0117] DSC testing showed no cracking at the magnesium-copper-tantalum interface when heated from room temperature to 500℃. The prepared sheet exhibited a tensile yield strength of 210 MPa, a tensile strength of 306 MPa, an elongation of 6%, an interfacial bond strength of 57.5 MPa, and a room temperature conductivity of 32 ± 2 KS / mm.

[0118] Example 8

[0119] This invention provides a method for preparing a layered composite material and the layered composite material itself. The preparation method includes:

[0120] S1 stacks the annealed AZ31B plate (first plate), Cu foil (second plate), and Ta plate (third plate) to form the smallest unit, with the Cu foil located between the AZ31B plate and the Ta plate; the tensile strength of the Cu foil is 220 MPa; the thickness of the AZ31B plate is 1 mm, the thickness of the Cu foil is 0.1 mm, and the thickness of the Ta plate is 0.5 mm.

[0121] The surfaces of AZ31B and Ta plates were polished along the rolling direction and transverse direction respectively. The surface roughness Ra of the transverse and longitudinal directions after polishing was 5-15μm. After polishing, the Ta plate, AZ31B plate and Cu foil were cleaned with anhydrous ethanol and then vacuum dried.

[0122] The pretreated plates were stacked in the order of AZ31B|Cu|Ta|Cu|AZ31B, and the edges were fixed by welding or rivets. Then they were placed in a heating furnace and kept at 350°C for 30 minutes.

[0123] S2 stacks the preheated AZ31B|Cu|Ta|Cu|AZ31B. The first rolling pass has a reduction of 75%, a roll temperature of 350℃, and a rolling speed of 0.05m / s. The second rolling pass has a reduction of 20%, a roll temperature of 350℃, and a rolling speed of 0.05m / s. The third rolling pass has a reduction of 20%, a roll temperature of 350℃, and a rolling speed of 0.05m / s.

[0124] Finally, the surface of the rolled sheet is treated with an angle grinder to remove the oxide layer and impurity layer, and a layered composite sheet with the smallest unit being AZ31B|Cu|Ta|Cu|AZ31B is obtained.

[0125] DSC testing showed that the magnesium-copper-tantalum interface did not crack when heated from room temperature to 500℃. The prepared plate had a tensile yield strength of 278 MPa, a tensile strength of 345 MPa, an elongation of 8%, an interfacial bond strength of 67 MPa, and a room temperature conductivity of 29 ± 2 KS / mm.

[0126] Example 9

[0127] Unlike Example 1, in this example, during the stacking process of the rolling process, the smallest unit after the first rolling pass is stacked at 90° and then rolled. The stacking and rolling are repeated, and each time they are stacked at 90°. The reduction during the rolling process is 60%.

[0128] DSC testing showed no cracking at the magnesium-copper-tantalum interface when heated from room temperature to 500℃. The prepared sheet exhibited a tensile yield strength of 345 MPa, a tensile strength of 425 MPa, an elongation of 8%, an interfacial bond strength of 75 MPa, and a room temperature conductivity of 39 ± 3 KS / mm.

[0129] Comparative Example 1

[0130] Unlike Example 1, Cu foil is not added to the layered composite material in this comparative example.

[0131] The prepared layered composite material, such as Figure 3 As shown, the Mg / Ta rolled plate exhibits delamination, making effective bonding impossible.

[0132] Comparative Example 2

[0133] Unlike Example 1, this comparative example uses a cold rolling process, which eliminates the need for preheating, heat preservation, and setting of roll temperature.

[0134] The prepared layered composite material, such as Figure 4 As shown in 4a and 4b, it can be seen that the Mg / Cu / Ta / Cu / Mg rolled plate exhibits severe delamination, along with numerous surface cracks and fissures, making effective bonding impossible. This indicates that selecting appropriate heating and rolling temperatures is a key factor in the successful preparation of the multi-interface scattering loss electromagnetic shielding composite material in this invention.

[0135] Comparative Example 3

[0136] Unlike Example 1, in this comparative example, the thickness of the AZ31B plate is 0.8 mm, the thickness of the Cu foil is 0.04 mm, and the thickness of the Ta plate is 0.4 mm.

[0137] In the prepared layered composite material interface, the Cu layer was partially penetrated. The prepared sheet had a tensile yield strength of 136 MPa, a tensile strength of 185 MPa, an elongation of 5%, and an interfacial bond strength of 26 MPa.

[0138] Comparative Example 4

[0139] Unlike Example 1, in this comparative example, the thickness of the AZ31B plate is 12mm, the thickness of the Cu foil is 0.9mm, and the thickness of the Ta plate is 6mm.

[0140] DSC testing showed that the magnesium-copper-tantalum interface cracked after being heated from room temperature to 500℃ and held for 30 minutes. Meanwhile, the prepared plate had a tensile yield strength of 136 MPa, a tensile strength of 156 MPa, an elongation of 4%, and an interfacial bond strength of 31 MPa.

[0141] Comparative Example 5

[0142] Unlike Example 1, in this comparative example, Cu foil was replaced with Al foil. Its tensile strength is 45 MPa.

[0143] DSC testing showed that when the temperature was increased from room temperature to 500℃, cracks appeared at the interface, but no micro-ripple structure was found. The prepared sheet had a tensile yield strength of 145 MPa, a tensile strength of 225 MPa, an elongation of 7%, and an interfacial bond strength of 28 MPa.

[0144] Comparative Example 6

[0145] Unlike Example 1, in this comparative example, the thickness of the AZ31B plate is 2.2 mm, the thickness of the Cu foil is 0.1 mm, and the thickness of the Ta plate is 0.5 mm.

[0146] DSC testing showed that the magnesium-copper-tantalum interface cracked when heated from room temperature to 500℃. The prepared plate had a tensile yield strength of 166 MPa, a tensile strength of 235 MPa, an elongation of 6%, and an interfacial bond strength of only 28 MPa.

[0147] Comparative Example 7

[0148] Unlike Example 1, in this comparative example, the thickness of the AZ31B plate is 1 mm, the thickness of the Cu foil is 0.1 mm, and the thickness of the Ta plate is 1 mm.

[0149] DSC testing showed that the magnesium-copper-tantalum interface cracked when heated from room temperature to 500℃. The prepared plate had a tensile yield strength of 171 MPa, a tensile strength of 243 MPa, an elongation of 6%, and an interfacial bond strength of 31 MPa.

[0150] Comparing Comparative Examples 1-2 with Example 1, it is evident that a reasonable rolling process combined with the addition of Cu foil can produce layered composite materials. Cold rolling or direct rolling cannot effectively bond the various plates. Comparing Example 1 with Comparative Examples 3-4, it is clear that if the Cu foil is too thin, some Cu layers are penetrated, resulting in low bonding strength of the layered composite material and cracking of the magnesium-copper-tantalum interface in DSC testing. Conversely, if the Cu foil is too thick, the micro-corrugated structure cannot be effectively generated during subsequent rolling, leading to cracking of the magnesium-copper-tantalum interface in subsequent DSC testing. Comparing Example 1 with Comparative Examples 5-7, it is evident that the strength of the second plate and the thickness settings between layers affect the subsequent depth of the corrugated structure, resulting in a reduced rate of macroscopic or microscopic corrugated structure formation.

[0151] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. 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 a layered composite material, characterized in that, Includes the following steps: The first, second, and third plates after annealing are stacked to form the smallest unit. The first plate has an HCP crystal structure, the second plate has an FCC crystal structure, and the third plate has a BCC crystal structure. The second plate is located between the first and third plates. The tensile strength of the second plate is 150MPa-300MPa; The thickness ratio of the first plate, the second plate, and the third plate satisfies 20:(1-2):(10-15), and the thickness of the second plate is 0.05mm-0.80mm; The smallest unit is rolled, and the reduction in the first rolling pass is 50%-75%. The smallest unit is preheated before rolling, and is covered with aluminum foil. The heat preservation temperature is 150℃-350℃ and the heat preservation time is 15min-35min. The roll temperature is 150℃-350℃.

2. The preparation method according to claim 1, characterized in that, The first plate is one or more of the AZ31, AZ91, ZK60, ZK61, and Mg-RE series alloy plates; And / or, the second plate is one or more of copper or copper alloy; And / or, the third plate is tantalum.

3. The preparation method according to any one of claims 1-2, characterized in that, The smallest unit is arranged using a first plate, a second plate, a third plate, a second plate, and a first plate.

4. The preparation method according to claim 3, characterized in that, The minimum unit shall be rolled in no more than two subsequent passes, and the reduction per pass shall be 10%-20%. or The smallest unit after the first rolling is stacked and then subjected to stacking rolling. The stacking and rolling are repeated no more than five times, and the reduction of the stacking rolling is 50%-65%.

5. The preparation method according to claim 4, characterized in that, The smallest units after the first rolling are stacked at 90° and then rolled together. The stacking is repeated no more than five times, and each time they are stacked at 90°. The rolling reduction is 55%-65%.

6. The preparation method according to claim 4 or 5, characterized in that, The rolling speed for the first rolling pass, subsequent rolling passes, and stacking rolling is 0.015 m / s to 0.05 m / s.

7. The preparation method according to claim 4 or 5, characterized in that, Before the stacking process, the surface of the composite material in the first rolling or the previous stacking process is polished, and then it is heated in a vacuum environment or an inert gas atmosphere at a temperature of 300℃-350℃ for a holding time of 10min-20min.

8. The preparation method according to claim 1, characterized in that, The first and third plates after annealing are polished, including rolling and transverse polishing. The surface roughness Ra of the transverse and rolling surfaces after polishing is 5µm-15µm.

9. A layered composite material, characterized in that, The layered composite material is prepared by any one of the preparation methods described in claims 1-8.

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