High modulus magnesium-based composite material and its preparation method and application

Abstract

The application discloses a high-modulus magnesium-based composite material and a preparation method and application thereof, and belongs to the technical field of magnesium alloy materials. The preparation raw material of the magnesium-based composite material comprises micron Ti particles coated with nano Al and magnesium-aluminum-zinc alloy powder; the mass of the micron Ti particles and the nano Al powder is 10wt%-15wt% and 5wt%-9wt% of the mass of the magnesium-aluminum-zinc alloy powder respectively; the magnesium-aluminum-zinc alloy powder contains 1wt%-9wt% of Al and 0.5wt%-1.5wt% of Zn, and the balance is Mg; the magnesium-aluminum-zinc alloy powder forms a matrix of the magnesium-based composite material; the nano Al powder and the Mg in the matrix form an Al2O3 composite MgO nano layer with a semi-coherent orientation relationship at the interface; and the Al element is segregated at the grain boundary of the matrix. The magnesium-based composite material has excellent strength, plasticity and elastic modulus, and can meet the requirements of 3C electronic product structural parts.

Description

Technical Field

[0001] This invention relates to the field of magnesium alloy materials technology, and more specifically, to a high-modulus magnesium-based composite material, its preparation method, and its application. Background Technology

[0002] As consumer electronics (3C) products trend towards thinner, lighter, and higher-performance designs, the application of lightweight materials has become a significant industry trend. High-modulus magnesium-based composite materials, with their excellent specific strength, specific stiffness, electromagnetic shielding properties, and good heat dissipation, have become ideal structural materials for high-end 3C products such as laptops, smartphones, tablets, and wearable devices.

[0003] Traditional 3C products often use aluminum alloy or engineering plastics for their outer casing and internal support structure, but aluminum alloy has a high density (approximately 2.7 g / cm³). 3 Engineering plastics, on the other hand, lack sufficient stiffness and strength. In contrast, magnesium-based composites have a density of only 1.7 g / cm³. 3 ~2.0g / cm 3 By introducing high-modulus reinforcing phases, the elastic modulus of magnesium can be increased to over 60 GPa while maintaining excellent impact resistance and dimensional stability. However, the elastic modulus of pure magnesium and traditional magnesium alloys is relatively low (typically 40 GPa to 45 GPa), limiting their application in load-bearing structural components. Currently, the main methods for improving the elastic modulus of magnesium-based composites include alloying (such as adding rare earth elements) and compositing (such as introducing ceramic particles like SiO2, Al2O3, and ZrO2). However, composites prepared by traditional mechanical mixing methods are prone to problems such as uneven distribution of reinforcing phases and poor interfacial wettability, leading to unstable mechanical properties of the composites. In addition, the significant difference in thermal expansion coefficients between the reinforcing phase and the magnesium matrix can easily generate residual stress during hot working, affecting the mechanical properties and dimensional stability of the material.

[0004] In view of this, the present invention is proposed. Summary of the Invention

[0005] The purpose of this invention is to provide a high-modulus magnesium-based composite material, its preparation method, and its application, so as to solve or improve the above-mentioned technical problems.

[0006] This invention can be implemented as follows: In a first aspect, the present invention provides a high-modulus magnesium-based composite material, wherein the raw materials for preparing the high-modulus magnesium-based composite material include micron-sized Ti particles coated with nano-Al powder and magnesium-aluminum-zinc alloy powder. The micron-sized Ti particles coated with nano-Al powder are obtained by coating micron-sized Ti particles with nano-Al powder. The mass of the micron-sized Ti particles is 10wt%~15wt% of the magnesium-aluminum-zinc alloy powder, and the mass of the nano-Al powder is 5wt%~9wt% of the magnesium-aluminum-zinc alloy powder. The magnesium-aluminum-zinc alloy powder contains 1wt%~9wt% Al and 0.5wt%~1.5wt% Zn, with the balance being Mg. Magnesium-aluminum-zinc alloy powder forms a high-modulus magnesium-based composite matrix; Al element segregation exists at the grain boundaries of the matrix; Nano-Al particles coated with nano-Al powder form an Al2O3 composite MgO nanolayer in situ at the interface with Mg in the matrix. The Al2O3 composite MgO nanolayer includes an inner MgO layer and an outer Al2O3 layer. The thickness of the inner MgO layer is 10nm~30nm, and the thickness of the outer Al2O3 layer is 10nm~60nm.

[0007] In an optional embodiment, the high-modulus magnesium-based composite material has at least one of the following characteristics: Feature 1: The average particle size of the magnesium-aluminum-zinc alloy powder is 50μm~100μm; Feature 2: The average particle size of the nano-Al powder is 5nm~50nm; Feature 3: The average particle size of the micron-sized Ti particles is 5 μm to 15 μm; Feature 4: In the micron-sized Ti particles coated with nano-Al powder, the nano-Al powder is uniformly coated on the surface of the micron-sized Ti particles; Feature 5: The coating thickness of the nano-Al powder is 10nm~100nm; Feature 6: The Al element present at the grain boundaries of the matrix accounts for 6wt%~9wt% of the matrix mass; Feature 7: The grains of high-modulus magnesium-based composites are mainly in an equiaxed state after recrystallization, and there is no obvious texture orientation; Feature 8: The average grain size of the high-modulus magnesium-based composite material is 1.0 μm to 2.5 μm; Feature 9: The tensile strength of the high-modulus magnesium-based composite material is not less than 360 MPa; Feature 10: The yield strength of the high-modulus magnesium-based composite material is not less than 250 MPa; Feature 11: The elastic modulus of the high-modulus magnesium-based composite material is 60 GPa to 100 GPa.

[0008] Secondly, the present invention provides a method for preparing a high-modulus magnesium-based composite material as described in the foregoing embodiments, comprising the following steps: ball milling micron-sized Ti particles coated with nano-Al powder with magnesium-aluminum-zinc alloy powder, followed by spark plasma sintering, homogenization treatment and hot extrusion.

[0009] In an optional embodiment, the preparation of micron-sized Ti particles coated with nano-Al powder includes: coating the surface of micron-sized Ti particles with nano-Al powder by magnetron sputtering; The process parameters for magnetron sputtering are: sputtering power of 80W~200W, working pressure range of 0.5Pa~2Pa, and sputtering time of 20min~60min.

[0010] In an optional embodiment, the ball milling includes: a ball-to-material ratio of 20:1 to 30:1, a ball milling time of 1 h to 2 h, and a ball milling speed of 200 rpm to 250 rpm.

[0011] In an optional embodiment, the temperature of the discharge plasma sintering is 500℃~550℃, the pressure of the discharge plasma sintering is 30MPa~40MPa, the discharge plasma sintering time is 3min~6min, and the discharge plasma sintering is followed by air cooling.

[0012] In an optional embodiment, the homogenization temperature is 300℃~400℃, and the homogenization time is 1h~2h.

[0013] In an optional embodiment, the hot extrusion temperature is 300℃~350℃, and the hot extrusion rate is 0.1mm / s~0.5mm / s.

[0014] Thirdly, the present invention provides an application of a high-modulus magnesium-based composite material as described in the foregoing embodiments, which is used to prepare structural components for 3C products.

[0015] Fourthly, the present invention provides a 3C product structural component, the raw material for which the 3C product structural component is prepared includes the high-modulus magnesium-based composite material of the aforementioned embodiments.

[0016] The beneficial effects of this invention include: The high-modulus magnesium-based composite material provided by this invention is prepared by mixing micron-sized Ti particles coated with nano-Al powder and magnesium-aluminum-zinc alloy powder in a specific ratio. Specifically, the nano-Al powder uniformly coated on the surface of the Ti particles forms an in-situ Al2O3 composite MgO nanolayer at the interface. Because the Al2O3 layer is extremely thin, it can exhibit an amorphous or nanocrystalline structure with high interfacial energy, which is beneficial for enhancing interfacial bonding. Furthermore, Al2O3 is a typical high-hardness, high-melting-point oxide with excellent chemical stability in the magnesium matrix, effectively hindering element diffusion at the interface and maintaining interfacial stability. Notably, there is lattice matching between the Al2O3 layer and the MgO layer, and between the MgO layer and the magnesium matrix, forming a low-energy semi-coherent interface, reducing stress concentration and significantly improving interfacial bonding. Moreover, the Al2O3 composite MgO layer forms a gradient transition structure in terms of thermal expansion coefficients; the thermal expansion coefficients of Al2O3, MgO, and Mg are 8 × 10⁻⁶. -6 / K, 13.5×10 -6 / K、25×10 -6 / K, which is the Al2O3 / MgO / Mg structure, can alleviate the residual stress caused by the mismatch of thermal expansion coefficients at the interface and improve the interfacial bonding strength.

[0017] This invention specifically controls the mass of the nano-Al powder coating on the Ti particles to be 5wt%~9wt% of the magnesium-aluminum-zinc alloy powder. The reason is that as the Al content increases, the thickness of the Al2O3 layer formed by the interfacial reaction of the composite material increases. With increasing thickness, the bulk energy gradually dominates, tending to form thermodynamically stable α-Al2O3. Because of its high hardness and poor plasticity, α-Al2O3 exhibits typical ceramic particle characteristics, significantly weakening the interfacial structure of the composite material. If the amount of coated nano-Al powder is too small, it cannot promote the self-oxidation reaction at the interface to form an Al2O3 composite MgO nanolayer.

[0018] Magnetron sputtering technology utilizes plasma bombardment of an aluminum target to sputter Al atoms at high energy levels and uniformly deposit them on the surface of Ti particles, enabling controllable coating of nanoscale Al layers. In the initial stage of magnetron sputtering deposition, when Al atoms reach the Ti particle surface, parameters such as sputtering power, operating pressure, and deposition distance can directly influence the nucleation and growth behavior of individual Al particles, forming discrete Al nanoparticles. As deposition continues, these initial nanoparticles merge through surface diffusion, eventually forming a continuous Al coating layer. The thickness of the coating layer is affected by parameters such as sputtering power, operating pressure, and deposition time. Therefore, by adjusting the deposition process parameters, the thickness of the Al coating layer and the Al powder particle size can be precisely controlled, while simultaneously achieving higher coating density and bonding strength.

[0019] Therefore, using magnetron sputtering to uniformly coat an appropriate amount of nano-Al powder onto the surface of micron-sized Ti particles as a reinforcing phase to strengthen magnesium-aluminum-zinc alloys helps improve the mechanical properties of magnesium-based composites, especially the elastic modulus, further expanding the application potential of magnesium-based composites. Furthermore, the presence of Al enrichment at the grain boundaries of this magnesium-based composite matrix helps suppress the formation of large-sized oxide inclusions at the interface, improving grain boundary bonding. Simultaneously, Al, through the solute drag effect, hinders grain boundary movement and significantly inhibits grain growth.

[0020] The magnesium-based composite material provided by this invention has high yield strength, tensile strength and elastic modulus, which can meet the requirements of structural components for 3C electronic products. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a SEM image of the micron-sized Ti particles coated with nano-Al powder in Example 1; Figure 2 EDS image of micron-sized Ti particles coated with nano-Al powder in Example 1; Figure 3 This is a SEM image of the longitudinal section of the high-modulus magnesium-based composite material in Example 1; Figure 4 This is a TEM image showing the microstructure of the Al2O3 composite MgO nanolayer in the high-modulus magnesium-based composite material of Example 1. Figure 5 This is a TEM image of the Al2O3 / MgO / Mg semi-coherent interface structure of the high-modulus magnesium-based composite material in Example 1. Figure 6 The energy dispersive spectral line scan is the Al element segregation at the grain boundaries of the high-modulus magnesium-based composite matrix in Example 1; Figure 7 This is a grain size diagram of the high-modulus magnesium-based composite material prepared in Example 1. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0024] The high-modulus magnesium-based composite material, its preparation method, and its application provided by this invention will be described in detail below.

[0025] The raw materials for preparing the high-modulus magnesium-based composite material provided by this invention include micron-sized Ti particles coated with nano-Al powder and magnesium-aluminum-zinc alloy powder.

[0026] In this invention, the mass of the micron-sized Ti particles is 10wt% to 15wt% of the magnesium-aluminum-zinc alloy powder, such as 10wt%, 10.5wt%, 11wt%, 11.5wt%, 12wt%, 12.5wt%, 13wt%, 13.5wt%, 14wt%, 14.5wt%, or 15wt%, or other values ​​within the range of 10wt% to 15wt%. If the amount of micron-sized Ti particles is too small, it is not conducive to improving the strength of the magnesium-based composite material; if the amount of micron-sized Ti particles is too large, there will be too many interfaces between the micron-sized Ti particles and the matrix, which is not conducive to improving the plasticity of the magnesium-based composite material.

[0027] The mass of nano-Al powder is 5wt% to 9wt% of the magnesium-aluminum-zinc alloy powder, such as 5wt%, 5.5wt%, 6wt%, 6.5wt%, 7wt%, 7.5wt%, 8wt%, 8.5wt%, or 9wt%, or other values ​​within the 5wt% to 9wt% range. If the amount of nano-Al powder is too small, the coating area of ​​the micron-sized Ti particles will be small, which is not conducive to the auto-oxidation reaction of Al at the interface, and cannot effectively improve the interfacial bonding and the mechanical properties of the magnesium-based composite material. If the amount of nano-Al powder is too large, it is not conducive to the formation of a uniformly dispersed coating on the surface of the micron-sized Ti particles. Furthermore, if the content of nano-Al powder is too high, excessive auto-oxidation reaction can easily occur at the interface, forming a thicker Al2O3 layer, which is not conducive to strong interfacial bonding, nor to grain refinement and improvement of the mechanical properties of the magnesium-based composite material.

[0028] By controlling the mass of nano-Al powder coating on the surface of Ti particles to 5wt%~9wt% of the magnesium-aluminum-zinc alloy powder, the thickness of the Al2O3 layer formed by the interfacial reaction of the composite material increases with the increase of the mass of nano-Al powder. With the increase of thickness, the bulk phase energy gradually dominates, and it is more inclined to form thermodynamically stable α-Al2O3. Because of its high hardness and poor plasticity, it exhibits typical ceramic particle characteristics, which significantly weakens the interfacial structure of the composite material. If the amount of nano-Al powder coating is too small, it cannot promote the self-oxidation reaction at the interface to form an Al2O3 composite MgO nanolayer. Therefore, selecting an appropriate amount of nano-Al powder to coat micron-sized Ti particles to reinforce magnesium-aluminum-zinc alloy helps to improve the mechanical properties of magnesium-based composite materials, especially the elastic modulus, and expands the application prospects of magnesium-based composite materials. In addition, Al element enrichment exists at the grain boundaries in the magnesium-based composite matrix, which inhibits the formation of large-sized oxide inclusions at the interface and improves the grain boundary bonding. The segregation of Al elements at the grain boundaries of the magnesium matrix can hinder grain boundary movement and significantly refine the grain size of the composite material. Continuing from the above, by adjusting the mass of nano-Al powder coating the surface of micron-sized Ti particles within the range provided by this invention, the thickness of the composite nanolayer at the interface of magnesium-based composite materials can be designed more precisely, the grain size can be refined, and the strength, plasticity, and especially the elastic modulus of high-modulus magnesium-based composite materials can be effectively controlled.

[0029] In this invention, the magnesium-aluminum-zinc alloy powder contains 1 wt% to 9 wt% Al and 0.5 wt% to 1.5 wt% Zn, with the balance being Mg. The mass of Al in the magnesium-aluminum-zinc alloy powder can be 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, 3 wt%, 3.5 wt%, 4 wt%, 4.5 wt%, 5 wt%, 5.5 wt%, 6 wt%, 6.5 wt%, 7 wt%, 7.5 wt%, 8 wt%, 8.5 wt%, or 9 wt%, or other values ​​within the range of 1 wt% to 9 wt%. The mass of Zn in the magnesium-aluminum-zinc alloy powder can be 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, 0.9 wt%, 1.0 wt%, 1.1 wt%, 1.2 wt%, 1.3 wt%, 1.4 wt%, or 1.5 wt%, or other values ​​within the range of 0.5 wt% to 1.5 wt%.

[0030] In this invention, nano-Al particles coated with nano-Al powder and Mg in the matrix form an Al2O3 composite MgO nanolayer in situ at the interface. The Al2O3 composite MgO nanolayer comprises an inner MgO layer and an outer Al2O3 layer. The thickness of the inner MgO layer is 10 nm to 30 nm (preferably 10 nm to 20 nm), such as 10 nm, 15 nm, 20 nm, 25 nm, or 30 nm, or other values ​​within the 10 nm to 30 nm range. The thickness of the outer Al2O3 layer is 10 nm to 60 nm (preferably 15 nm to 35 nm), such as 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, 55 nm, or 60 nm, or other values ​​within the 10 nm to 60 nm range.

[0031] Magnesium-aluminum-zinc alloy powder forms the matrix of a high-modulus magnesium-based composite material, with Al element segregation at the grain boundaries. This Al element segregation helps to suppress the formation of excessive oxide inclusions at the grain boundaries, thereby improving the interfacial bonding strength of the magnesium-based composite material. At the same time, the Al solute drag effect hinders grain boundary movement, refining the grain size of the magnesium-based composite material.

[0032] It should be noted that the Al2O3 composite MgO nanolayer in this invention can facilitate continuous load transfer at the interface and improve interfacial bonding. MgO itself has an elastic modulus of 250 GPa, significantly higher than that of the magnesium matrix and Ti particles, which can significantly improve the elastic modulus of the composite material. If the MgO layer is thin, its effect on improving the elastic modulus is weak; if the MgO layer is thick, the structure is loose and contains pores, which can easily lead to stress concentration and deteriorate the interfacial bonding strength under load. Al2O3 itself has an elastic modulus of 380 GPa, therefore the outer Al2O3 layer can further improve the elastic modulus of the composite material. Simultaneously, the Al2O3 layer is relatively dense, with a relatively uniform thin band distribution, which can significantly hinder element diffusion between the inner MgO layer and the magnesium matrix, and the thickness of the inner MgO layer can be controlled. If the outer layer of Al2O3 is too thin, it will not be conducive to improving the elastic modulus and the effect of hindering element diffusion will be relatively weak, which will lead to stress concentration if the inner layer of MgO is too thick. If the outer layer of Al2O3 is too thick, since Al2O3 is a ceramic phase with high hardness, the plastic deformation capacity of a thicker Al2O3 layer is poor, which is not conducive to interface coordination plastic deformation, and the mechanical properties of the composite material will decrease.

[0033] In some optional embodiments, the average particle size of the magnesium-aluminum-zinc alloy powder is 50 μm to 100 μm, such as 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, 75 μm, 80 μm, 85 μm, 90 μm, 95 μm or 100 μm, or other values ​​in the range of 50 μm to 100 μm.

[0034] If the average particle size of magnesium-aluminum-zinc alloy powder is less than 50 μm, the magnesium alloy powder is relatively active, which is not conducive to ensuring the safety of the hot sintering and hot extrusion preparation process; if the average particle size of magnesium-zinc-zinc alloy powder is greater than 100 μm, it will result in larger pores between powders, which is not conducive to obtaining sintered dense magnesium-based composite materials with fine grain size.

[0035] In some alternative embodiments, the average particle size of the nano-Al powder is 5nm to 50nm, such as 5nm, 10nm, 15nm, 20nm, 25nm, 30nm, 35nm, 40nm, 45nm or 50nm, or other values ​​in the range of 5nm to 50nm.

[0036] If the average particle size of nano-Al powder is less than 5nm, its large surface area makes it prone to agglomeration, which is not conducive to uniform coating on the surface of micron-sized Ti particles, and the improvement of interfacial effect is significantly reduced. If the average particle size of nano-Al powder is greater than 50nm, the effect of coating micron-sized Ti particles is significantly reduced, and the coarse Al2O3 phase formed by the interfacial reaction is not conducive to further refining the grain size. The thicker interfacial layer will also significantly reduce the interfacial bonding force.

[0037] In some alternative implementations, the average particle size of the micron-sized Ti particles can be 5μm to 15μm, such as 5μm, 6μm, 7μm, 8μm, 9μm, 10μm, 11μm, 12μm, 13μm, 14μm or 15μm, or other values ​​within the range of 5μm to 15μm.

[0038] If the average particle size of micron-sized Ti particles is greater than 15 μm, the pores between the powder particles are too large, which is not conducive to the dense sintering of the composite material. If the average particle size of micron-sized Ti particles is less than 5 μm, they are prone to agglomeration and are difficult to disperse uniformly.

[0039] In some optional embodiments, in the micron-sized Ti particles coated with nano-Al powder, the nano-Al powder is uniformly coated on the surface of the micron-sized Ti particles, and the coating thickness of the nano-Al powder is 10nm~100nm, such as 10nm, 30nm, 50nm, 80nm or 100nm, or other values ​​in the range of 10nm~100nm.

[0040] If the coating thickness of the nano-Al powder is too thin, it is not conducive to the self-reaction at the interface of the composite material to form a dense Al2O3 layer. This has a negative impact on hindering the diffusion of elements at the interface and controlling the thickness of the MgO inner layer. It also does not significantly improve the elastic modulus of the magnesium-based composite material. If the coating thickness of the nano-Al powder is too thick, it is not conducive to the uniform dispersion of nano-Al on the surface of micron-sized Ti particles. After the self-oxidation reaction, it cannot form a thin strip-shaped Al2O3 layer at the interface of the magnesium-based composite material. A thicker Al2O3 layer is not conducive to the coordinated deformation with the magnesium matrix, resulting in a significant decrease in the interfacial bonding strength.

[0041] In some alternative embodiments, the Al elements segregated at the grain boundaries of the matrix account for 6wt% to 9wt% of the matrix mass, such as 6wt%, 6.5wt%, 7wt%, 7.5wt%, 8wt%, 8.5wt%, or 9wt%, or other values ​​within the range of 6wt% to 9wt%.

[0042] If there is too little Al segregation at the matrix grain boundaries, it cannot significantly inhibit grain growth; if there is too much Al segregation at the matrix grain boundaries, it will promote the formation of brittle intermetallic compounds such as Mg. 17 Al 12 The precipitation of excess Mg 17 Al 12 The phases tend to form a continuous network distribution, which disrupts the continuity of the matrix and is not conducive to improving the mechanical properties of composite materials.

[0043] In some alternative embodiments, the grains of the high-modulus magnesium-based composite material are mainly equiaxed after recrystallization and have no obvious texture orientation.

[0044] In some alternative embodiments, the average grain size of the high-modulus magnesium-based composite material can be 1.0 μm to 2.5 μm (e.g., 1.0 μm, 1.5 μm, 2 μm or 2.5 μm, etc.).

[0045] In some alternative implementations, the high-modulus magnesium-based composite material has a tensile strength of not less than 360 MPa.

[0046] In some alternative implementations, the yield strength of the high-modulus magnesium-based composite material is not less than 250 MPa.

[0047] In some alternative embodiments, the elastic modulus of the high-modulus magnesium-based composite material is 60 GPa to 100 GPa.

[0048] Continuing from the above, the high-modulus magnesium-based composite material provided by this invention is prepared by mixing micron-sized Ti particles coated with nano-Al powder and magnesium-aluminum-zinc alloy powder in a specific ratio. The nano-Al powder uniformly coated on the surface of the Ti particles forms an Al2O3 composite MgO nanolayer in situ at the interface of the composite material. Because the Al2O3 layer is extremely thin, it may exhibit an amorphous or nanocrystalline structure, possessing high interfacial energy, which is beneficial for enhancing interfacial bonding strength. Furthermore, Al2O3 is a typical high-hardness, high-melting-point oxide with excellent chemical stability in the magnesium matrix, effectively hindering element diffusion at the interface and maintaining interfacial stability. Notably, there is lattice matching between the Al2O3 layer and the MgO layer, and between the MgO layer and the magnesium matrix, forming a low-energy semi-coherent interfacial structure, reducing stress concentration. The Al2O3 composite MgO nanolayer forms a gradient transition structure in the coefficient of thermal expansion, namely Al2O3 / MgO / Mg, which can alleviate residual stress caused by the mismatch in the coefficient of thermal expansion and improve interfacial bonding strength.

[0049] The magnesium-based composite material provided by this invention has high yield strength, tensile strength and elastic modulus. The high elastic modulus can improve the structural stability of 3C electronic products, prevent large deformations during practical applications, enhance durability and achieve product lightweighting.

[0050] Accordingly, the present invention also provides a method for preparing the above-mentioned high-modulus magnesium-based composite material, comprising the following steps: ball milling micron-sized Ti particles coated with nano-Al powder with magnesium-aluminum-zinc alloy powder, followed by spark plasma sintering, homogenization treatment and hot extrusion.

[0051] In some alternative embodiments, the preparation of micron-sized Ti particles coated with nano-Al powder may include: coating the surface of micron-sized Ti particles with nano-Al powder by magnetron sputtering.

[0052] In-situ generation of ceramic phases in magnesium-based composites through interface design can achieve both uniform distribution of the reinforcing phase and significant improvement in the material's elastic modulus. Powder metallurgy offers advantages over traditional casting methods by precisely controlling the degree of interfacial reaction and product content during solid-state sintering. Among these methods, surface modification of reinforcing particles is one of the most effective means of interface control. Compared to the non-uniform coatings of electroblast deposition and the solution contamination problems of electroplating, magnetron sputtering has significant advantages. Its vacuum environment avoids oxidation, and the low-temperature process prevents thermal damage to Ti particles. The principle of magnetron sputtering technology is to use Ar plasma to bombard Al targets, causing sputtered Al atoms / nanoclusters to deposit on the surface of Ti particles to form a controllable coating layer. The sputtering power (too high a pressure leads to Al nanoparticle agglomeration) and the working pressure (higher pressure increases collisions and reduces particle size) jointly regulate the Al particle size, while the sputtering time directly affects the coating layer thickness. This precise control of the Al layer particle size and thickness can optimize the thermodynamic driving force and diffusion kinetics of subsequent interfacial reactions, thereby effectively improving the strength, toughness, and elastic modulus of the composite material. The process parameters for magnetron sputtering are: sputtering power of 80W~200W, working pressure of 0.5Pa~2Pa, and sputtering time of 20min~60min.

[0053] The sputtering power can be 80W, 100W, 120W, 140W, 160W, 180W or 200W, or other values ​​within the range of 80W to 200W.

[0054] In magnetron sputtering deposition, sputtering power has a significant impact on the particle size of Al particles. Increasing sputtering power can greatly increase the sputtering yield of Al atoms and significantly improve the deposition rate. Higher sputtering power will significantly promote the surface migration and grain coalescence of Al particles, resulting in the formation of coarse Al particles; while lower power is conducive to obtaining fine and dispersed nanoscale Al particles, but may result in loose bonding between particles.

[0055] The working pressure can be 0.5Pa, 1Pa, 1.5Pa and 2Pa, or other values ​​within the range of 0.5Pa to 2Pa.

[0056] During magnetron sputtering, the working pressure has a significant impact on the particle size of deposited Al. High pressure conditions slow down the deposition rate due to particle scattering effects. When the working pressure is too high, the frequent collisions between sputtered particles and gas molecules reduce the kinetic energy of Al atoms, resulting in insufficient migration of particles to the surface and the formation of a loose structure with large particle size. On the other hand, if the pressure is too low, Al atoms maintain a high energy, promoting surface diffusion and forming fine nanoparticles.

[0057] The sputtering time can be 20 min, 30 min, 40 min, 50 min or 60 min, or other values ​​within the range of 20 min to 60 min.

[0058] In magnetron sputtering deposition, sputtering time plays a crucial role in regulating the thickness of the Al coating. With prolonged sputtering time, the initially deposited Al nanoparticles undergo continuous atomic deposition and surface diffusion. Through Ostwald ripening and grain boundary migration, the particles merge and grow, eventually forming a stable grain structure. Extending the sputtering time can significantly increase the Al layer thickness. However, excessively long deposition times can lead to the formation of coarse columnar crystals and an excessively thick interfacial layer, causing significant stress accumulation. Therefore, controlling the sputtering time within a suitable range is essential to achieve an Al coating of ideal thickness, ensuring that the coating possesses both good density and strong interfacial bonding.

[0059] It should be noted that simply mechanically mixing nano-Al powder with micron-sized Ti particles, instead of preparing a form where nano-Al powder coats micron-sized Ti particles, will result in the formation of Ti-Al intermetallic compounds after mechanical ball milling, weakening the reinforcing effect of the Ti particles themselves. Furthermore, in subsequent preparation processes, Al element segregation cannot occur at the matrix grain boundaries, thus failing to improve grain boundary bonding strength and significantly reducing the effect of weakening grain size. The magnetron sputtering method of this invention can uniformly coat nano-Al powder onto the surface of micron-sized Ti particles, facilitating the formation of a thin strip-shaped Al₂O₃ layer and a MgO layer of suitable thickness in the composite material.

[0060] In some optional embodiments, the ball milling includes: a ball-to-material ratio of 20:1 to 30:1, a ball milling time of 1 h to 2 h, and a ball milling speed of 200 rpm to 250 rpm.

[0061] Among them, the ball-to-material ratio can be 20:1, 25:1 or 30:1 by mass, or other values ​​within the range of 20:1 to 30:1.

[0062] The ball milling time can be 1 hour, 1.5 hours, or 2 hours, or other values ​​within the range of 1 hour to 2 hours.

[0063] The ball mill speed can be 200rpm, 210rpm, 220rpm, 230rpm, 240rpm or 250rpm, or other values ​​within the range of 200rpm to 250rpm.

[0064] The ball milling speed directly affects the thickness of the Al2O3 composite MgO thin layer. If the ball milling speed is too low, it is not conducive to the formation of thin strip-shaped Al2O3 phase, and the interface is mainly composed of MgO layer. If the ball milling speed is too high, it is easy to destroy the structure of the Al2O3 phase composite MgO layer of the composite material, and the structural advantages of the composite cannot be fully utilized.

[0065] In some optional embodiments, the temperature of the discharge plasma sintering is 500℃~550℃, the pressure of the discharge plasma sintering is 30MPa~40MPa, the discharge plasma sintering time is 3min~6min, and the discharge plasma sintering is followed by air cooling.

[0066] The pressure for spark plasma sintering can be 30MPa, 32MPa, 35MPa, 38MPa or 40MPa, or other values ​​within the range of 30MPa to 40MPa.

[0067] The time for spark plasma sintering can be 3 min, 3.5 min, 4 min, 4.5 min, 5 min, 5.5 min or 6 min, or other values ​​within the range of 3 min to 6 min.

[0068] The time of the above-mentioned spark plasma sintering directly affects the thickness of the Al2O3 composite MgO thin layer. If the spark plasma sintering time is too short, it is not conducive to the formation of nanoscale Al2O3 thin strips. If the spark plasma sintering time is too long, it is easy to cause the thickness of the Al2O3 composite MgO layer to exceed 1μm, which significantly deteriorates the interfacial bonding strength.

[0069] In some optional embodiments, the homogenization temperature is 300°C to 400°C, and the homogenization time is 1 hour to 2 hours.

[0070] The homogenization temperature can be 300℃, 320℃, 350℃, 380℃ or 400℃, or other values ​​within the range of 300℃ to 400℃.

[0071] The homogenization time can be 1 hour, 1.5 hours, or 2 hours, or other values ​​within the range of 1 hour to 2 hours.

[0072] In some alternative embodiments, the hot extrusion temperature is 300°C to 350°C, and the hot extrusion rate is 0.1 mm / s to 0.5 mm / s.

[0073] The hot extrusion temperature can be 300℃, 310℃, 320℃, 330℃, 340℃ or 350℃, or other values ​​within the range of 300℃ to 350℃.

[0074] The hot extrusion rate can be 0.1 mm / s, 0.2 mm / s, 0.3 mm / s, 0.4 mm / s or 0.5 mm / s, or other values ​​within the range of 0.1 mm / s to 0.5 mm / s.

[0075] The hot extrusion rate directly affects the shape of Al2O3 and the compactness of MgO. If the hot extrusion rate is too slow, it promotes the diffusion of Al into the Mg matrix, forming Mg at the interface. 17 Al 12 The brittle phase replaces part of the Al2O3 / MgO layer, leading to excessive growth of the MgO layer and reducing the interfacial bonding strength. 17 Al 12 Brittle phases easily become crack propagation paths, leading to a decrease in the mechanical properties of composite materials. If the hot extrusion rate is too fast, the plastic deformation is severe, and the local temperature rise is high, which may result in: abnormal thickening of the Al2O3 layer, because high temperature promotes Al diffusion and reacts with residual oxygen to generate more Al2O3, but the distribution is uneven. At the same time, rapid deformation leads to stress concentration at the interface between the Mg matrix and Ti particles, and the MgO layer may fracture. Ultimately, the interface cracks and unbonded areas become stress concentration sources, leading to early fracture.

[0076] In conclusion, the preparation method provided by this invention is simple to operate, can effectively obtain Al2O3 composite MgO nanolayers with controllable thickness, and is beneficial to obtaining magnesium-based composite materials with excellent strength, plasticity and elastic modulus.

[0077] Furthermore, the present invention also provides an application of the above-mentioned high-modulus magnesium-based composite material, for example, the high-modulus magnesium-based composite material can be used to prepare structural parts for 3C products.

[0078] Accordingly, the present invention also provides a 3C product structural component, the raw materials for which the 3C product structural component is prepared include the above-mentioned high-modulus magnesium-based composite material.

[0079] For example, the 3C product structural component can be the shell of a 3C product.

[0080] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0081] Example 1 This embodiment provides a high-modulus magnesium-based composite material, the preparation method of which includes: S1: Preparation of micron-sized Ti particles coated with nano-Al powder.

[0082] Micron-sized Ti particles coated with nano-Al powder were obtained by magnetron sputtering with the following process parameters: sputtering power of 80W, working pressure of 0.5Pa, and sputtering time of 20min.

[0083] The average particle size of the nano-Al powder is 5 nm, and the mass of the nano-Al powder is 5 wt% of the magnesium-aluminum-zinc alloy powder.

[0084] SEM image of the nano-Al-coated micron-sized Ti particles is shown below. Figure 1 As shown, by Figure 1 It can be seen that nano-Al powder was successfully coated on the surface of micron-sized Ti particles. The coating thickness of the nano-Al powder is 10 nm. The EDS image of the micron-sized Ti particles coated with nano-Al is shown below. Figure 2 As shown, by Figure 2 It can be seen that the Al element distribution on the surface of micron-sized Ti particles is relatively uniform, proving the effectiveness of the magnetron sputtering method.

[0085] S2: Micron-sized Ti particles coated with nano-Al powder are ball-milled with magnesium-aluminum-zinc alloy powder.

[0086] The magnesium-aluminum-zinc alloy powder contains 9 wt% Al and 1 wt% Zn, with the balance being Mg. The average particle size of the magnesium-aluminum-zinc alloy powder is 80 μm, the average particle size of the micron-sized Ti particles is 10 μm, and the mass of the micron-sized Ti particles accounts for 10 wt% of the magnesium-aluminum-zinc alloy powder.

[0087] The ball-to-material ratio was 25:1, the ball milling time was 1.5 hours, and the ball milling speed was 220 rpm.

[0088] S3: Perform spark plasma sintering on the material obtained from ball milling.

[0089] The temperature of the discharge plasma sintering was 500℃, the pressure of the discharge plasma sintering was 35MPa, the discharge plasma sintering time was 5min, and the discharge plasma sintering was followed by air cooling.

[0090] S4: Homogenize the material after spark plasma sintering.

[0091] The homogenization process was carried out at a temperature of 350℃ for 1.5 hours.

[0092] S5: Hot extrusion of the homogenized material.

[0093] The hot extrusion temperature is 350℃, and the hot extrusion rate is 0.1 mm / s.

[0094] The longitudinal section SEM image of the high-modulus magnesium-based composite material prepared in this embodiment is shown below. Figure 3 As shown, by Figure 3 It can be seen that Ti particles are uniformly distributed within the composite material, forming a composite ceramic layer at the interface. The bonding is relatively dense, and no voids or other defects were found at the interface. A TEM image of the nanoscale Al₂O₃ composite MgO nanolayer in this high-modulus magnesium-based composite material is shown below. Figure 4 As shown, by Figure 4As can be seen, a composite layer is formed at the interface, with the outer layer being a nanoribbon-like structure. The thickness of the inner MgO layer is 30 nm, and the thickness of the outer Al2O3 layer is 10 nm. A TEM image of the Mg / Al2O3 / MgO semi-coherent structure is shown below. Figure 5 As shown, by Figure 5 It can be seen that the interplanar spacing of the (102) crystal plane of the Mg phase is 0.19 nm, the interplanar spacing of the (113) crystal plane of the Al2O3 phase is 0.20 nm, and the interplanar spacing of the (222) crystal plane of the MgO phase is 0.21 nm. The Al2O3 / Mg interface exhibits a semi-coherent orientation relationship, and the Al2O3 / MgO interface also exhibits a semi-coherent orientation relationship, with a mismatch degree of about 5% in both cases. The segregating energy spectrum of Al elements at the grain boundaries of the matrix in this high-modulus magnesium-based composite material is shown in the following image. Figure 6 As shown, by Figure 6 It can be seen that Al elements exhibit significant segregation at the grain boundaries of the matrix, accounting for 6 wt% of the matrix mass. The grain size diagram of this high-modulus magnesium-based composite material is shown below. Figure 7 As shown, by Figure 7 It can be seen that the grains are mainly equiaxed after recrystallization, and the grain size is relatively small.

[0095] Example 2 This embodiment provides a high-modulus magnesium-based composite material, the preparation method of which includes: S1: Preparation of micron-sized Ti particles coated with nano-Al powder.

[0096] Micron-sized Ti particles coated with nano-Al powder were obtained by magnetron sputtering with the following process parameters: sputtering power of 140W, working pressure of 1.25Pa, and sputtering time of 40min.

[0097] The average particle size of the nano-Al powder is 30 nm, and the mass of the nano-Al powder is 7 wt% of the magnesium-aluminum-zinc alloy powder. The coating thickness of the nano-Al powder is 60 nm.

[0098] S2: Micron-sized Ti particles coated with nano-Al powder are ball-milled with magnesium-aluminum-zinc alloy powder.

[0099] The magnesium-aluminum-zinc alloy powder contains 7 wt% Al and 0.5 wt% Zn, with the balance being Mg. The average particle size of the magnesium-aluminum-zinc alloy powder is 50 μm, the average particle size of the micron-sized Ti particles is 5 μm, and the mass of the micron-sized Ti particles accounts for 12 wt% of the magnesium-aluminum-zinc alloy powder.

[0100] The ball-to-material ratio was 20:1, the ball milling time was 2 hours, and the ball milling speed was 200 rpm.

[0101] S3: Perform spark plasma sintering on the material obtained from ball milling.

[0102] The temperature of the discharge plasma sintering was 500℃, the pressure of the discharge plasma sintering was 30MPa, the discharge plasma sintering time was 6min, and the discharge plasma sintering was followed by air cooling.

[0103] S4: Homogenize the material after spark plasma sintering.

[0104] The homogenization process was carried out at a temperature of 300℃ for 2 hours.

[0105] S5: Hot extrusion of the homogenized material.

[0106] The hot extrusion temperature is 300℃, and the hot extrusion rate is 0.1mm / s.

[0107] In this embodiment, the thickness of the MgO inner layer is 21 nm, and the thickness of the Al2O3 outer layer is 28 nm. The Al element present at the grain boundaries of the matrix accounts for 7.5 wt% of the matrix mass.

[0108] Example 3 This embodiment provides a high-modulus magnesium-based composite material, the preparation method of which includes: S1: Preparation of micron-sized Ti particles coated with nano-Al powder.

[0109] Micron-sized Ti particles coated with nano-Al powder were obtained by magnetron sputtering with the following process parameters: sputtering power of 200W, working pressure of 2Pa, and sputtering time of 60min.

[0110] The average particle size of the nano-Al powder is 50 nm, and the mass of the nano-Al powder is 9 wt% of the magnesium-aluminum-zinc alloy powder. The coating thickness of the nano-Al powder is 100 nm.

[0111] S2: Micron-sized Ti particles coated with nano-Al powder are ball-milled with magnesium-aluminum-zinc alloy powder.

[0112] The magnesium-aluminum-zinc alloy powder contains 1 wt% Al and 1.0 wt% Zn, with the balance being Mg. The average particle size of the magnesium-aluminum-zinc alloy powder is 100 μm, the average particle size of the micron-sized Ti particles is 15 μm, and the mass of the micron-sized Ti particles accounts for 15 wt% of the magnesium-aluminum-zinc alloy powder.

[0113] The ball-to-material ratio was 30:1, the ball milling time was 1 hour, and the ball milling speed was 250 rpm.

[0114] S3: Perform spark plasma sintering on the material obtained from ball milling.

[0115] The temperature of the discharge plasma sintering was 550℃, the pressure of the discharge plasma sintering was 40MPa, the discharge plasma sintering time was 3min, and the discharge plasma sintering was followed by air cooling.

[0116] S4: Homogenize the material after spark plasma sintering.

[0117] The homogenization process was carried out at a temperature of 400℃ for 1 hour.

[0118] S5: Hot extrusion of the homogenized material.

[0119] The hot extrusion temperature is 350℃, and the hot extrusion rate is 0.5mm / s.

[0120] In this embodiment, the thickness of the MgO inner layer is 10 nm, and the thickness of the Al2O3 outer layer is 50 nm. The Al element present at the grain boundaries of the matrix accounts for 9 wt% of the matrix mass.

[0121] Comparative Example 1 The difference between this comparative example and Example 1 is that the mass of the micron-sized Ti particles is 20 wt% of the magnesium-aluminum-zinc alloy powder.

[0122] Comparative Example 2 The difference between this comparative example and Example 1 is that the average particle size of the micron-sized Ti particles is 20 μm.

[0123] Comparative Example 3 The difference between this comparative example and Example 1 is that the average particle size of the magnesium-aluminum-zinc alloy powder is 20 μm.

[0124] Comparative Example 4 The difference between this comparative example and Example 1 is that the average particle size of the magnesium-aluminum-zinc alloy powder is 120 μm.

[0125] Comparative Example 5 The difference between this comparative example and Example 1 is that the magnetron sputtering power is 250W.

[0126] Comparative Example 6 The difference between this comparative example and Example 1 is that the magnetron sputtering power is 50W.

[0127] Comparative Example 7 The difference between this comparative example and Example 1 is that the working voltage of magnetron sputtering is 5 Pa.

[0128] Comparative Example 8 The difference between this comparative example and Example 1 is that the working voltage of magnetron sputtering is 0.1 Pa.

[0129] Comparative Example 9 The difference between this comparative example and Example 1 is that the deposition time of magnetron sputtering is 2 hours.

[0130] Comparative Example 10 The difference between this comparative example and Example 1 is that the deposition time of magnetron sputtering is 10 min.

[0131] Comparative Example 11 The difference between this comparative example and Example 1 is that the micron-sized Ti particles coated with nano-Al powder are directly replaced with micron-sized Ti particles.

[0132] Comparative Example 12 The difference between this comparative example and Example 1 is that the micron-sized Ti particles coated with nano-Al powder are directly replaced with a mixture obtained by mechanically mixing micron-sized Ti particles and nano-Al powder.

[0133] Test case The results of Examples 1-3 and Comparative Examples 1-12 were statistically compared, and the results are shown in Table 1. The average grain size, yield strength, tensile strength, and elastic modulus of the high-modulus magnesium-based composite materials prepared in Examples 1-3 and Comparative Examples 1-12 were compared, and the results are shown in Table 2. The average grain size was tested according to GB / T 38532-2020 "Determination of Average Grain Size by Electron Backscatter Diffraction in Microbeam Analysis," the yield strength and tensile strength were tested according to GB / T228.1-2010 "Metallic Materials - Tensile Testing - Part 1: Room Temperature Test Method," and the elastic modulus was tested according to GB / T 38897-2020 "Ultrasonic Measurement Method for Elastic Modulus and Poisson's Ratio in Nondestructive Testing."

[0134] Table 1 Comparison of the microstructure of magnesium-based composite materials

[0135] Table 2 Test results of mechanical properties

[0136] As can be seen from Table 2, the high-modulus magnesium-based composite materials obtained in Examples 1-3 of the present invention have higher yield strength, tensile strength and elastic modulus than the magnesium-based composite materials obtained in Comparative Examples 1-12.

[0137] A comparison of Example 1 with Comparative Examples 1-12 shows that an Al2O3 thin strip nanolayer of appropriate thickness can effectively control the thickness of the MgO inner layer, while an Al2O3 composite MgO layer of suitable thickness facilitates the continuous transfer of load at the interface, synergistically improving the strength and toughness of the composite material. Simultaneously, the addition of the high-modulus Al2O3 phase, high-mass Ti particles, and the interface strengthening effect ultimately result in an elastic modulus exceeding 60 GPa for the composite material.

[0138] In summary, the high-modulus magnesium-based composite material provided by this invention has high yield strength, tensile strength and high elastic modulus, which can meet the requirements of structural components for 3C electronic products.

[0139] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A high-modulus magnesium-based composite material, characterized in that, The raw materials for preparing the high-modulus magnesium-based composite material include micron-sized Ti particles coated with nano-Al powder and magnesium-aluminum-zinc alloy powder. The micron-sized Ti particles coated with nano-Al powder are obtained by coating micron-sized Ti particles with nano-Al powder. The mass of the micron-sized Ti particles is 10wt%~15wt% of the magnesium-aluminum-zinc alloy powder, and the mass of the nano-Al powder is 5wt%~9wt% of the magnesium-aluminum-zinc alloy powder. The magnesium-aluminum-zinc alloy powder contains 1wt%~9wt% Al and 0.5wt%~1.5wt% Zn, with the balance being Mg. The magnesium-aluminum-zinc alloy powder forms the matrix of the high-modulus magnesium-based composite material; Al element segregation exists at the grain boundaries of the matrix; The nano-Al in the micron-sized Ti particles coated with nano-Al powder and the Mg in the matrix form an Al2O3 composite MgO nanolayer in situ at the interface. The Al2O3 composite MgO nanolayer includes an inner MgO layer and an outer Al2O3 layer. The thickness of the inner MgO layer is 10nm~30nm, and the thickness of the outer Al2O3 layer is 10nm~60nm. The average particle size of the magnesium-aluminum-zinc alloy powder is 50μm~100μm; the average particle size of the micron-sized Ti particles is 5μm~15μm; in the micron-sized Ti particles coated with nano-Al powder, the nano-Al powder is uniformly coated on the surface of the micron-sized Ti particles. The preparation of the high-modulus magnesium-based composite material includes the following steps: ball milling micron-sized Ti particles coated with nano-Al powder with magnesium-aluminum-zinc alloy powder, followed by spark plasma sintering, homogenization treatment and hot extrusion. The preparation of the nano-Al powder coated micron-sized Ti particles includes: coating the surface of the micron-sized Ti particles with nano-Al powder by magnetron sputtering; wherein the process parameters of magnetron sputtering are sputtering power of 80W~200W, working pressure range of 0.5Pa~2Pa, and sputtering time of 20min~60min.

2. The high-modulus magnesium-based composite material according to claim 1, characterized in that, The high-modulus magnesium-based composite material has at least one of the following characteristics: Feature 1: The average particle size of the nano-Al powder is 5nm~50nm; Feature 2: The coating thickness of the nano-Al powder is 10nm~100nm; Feature 3: The Al element present at the grain boundaries of the matrix accounts for 6wt%~9wt% of the mass of the matrix; Feature 4: The high-modulus magnesium-based composite material has grains that are mainly in an equiaxed state after recrystallization, and there is no obvious texture orientation; Feature 5: The average grain size of the high-modulus magnesium-based composite material is 1.0 μm to 2.5 μm; Feature 6: The tensile strength of the high-modulus magnesium-based composite material is not less than 360 MPa; Feature 7: The yield strength of the high-modulus magnesium-based composite material is not less than 250 MPa; Feature 8: The elastic modulus of the high-modulus magnesium-based composite material is 60 GPa to 100 GPa.

3. A method for preparing a high-modulus magnesium-based composite material as described in claim 1 or 2, characterized in that, Includes the following steps: Micron-sized Ti particles coated with nano-Al powder were ball-milled and mixed with magnesium-aluminum-zinc alloy powder, followed by spark plasma sintering, homogenization treatment and hot extrusion. The preparation of the nano-Al powder coated micron-sized Ti particles includes: coating the surface of the micron-sized Ti particles with nano-Al powder by magnetron sputtering; wherein the process parameters of magnetron sputtering are sputtering power of 80W~200W, working pressure range of 0.5Pa~2Pa, and sputtering time of 20min~60min.

4. The preparation method according to claim 3, characterized in that, Ball milling includes: balls The material ratio is 20:1 to 30:1, the ball milling time is 1h to 2h, and the ball milling speed is 200rpm to 250rpm.

5. The preparation method according to claim 3, characterized in that, The temperature of the discharge plasma sintering is 500℃~550℃, the pressure of the discharge plasma sintering is 30MPa~40MPa, the discharge plasma sintering time is 3min~6min, and the discharge plasma sintering is followed by air cooling.

6. The preparation method according to claim 3, characterized in that, The homogenization treatment temperature is 300℃~400℃, and the homogenization treatment time is 1h~2h.

7. The preparation method according to claim 3, characterized in that, The hot extrusion temperature is 300℃~350℃, and the hot extrusion rate is 0.1mm / s~0.5mm / s.

8. The application of a high-modulus magnesium-based composite material as described in claim 1 or 2, characterized in that, The high-modulus magnesium-based composite material is used to prepare structural components for 3C products.

9. A structural component for 3C products, characterized in that, The raw materials for preparing the structural components of the 3C products include the high-modulus magnesium-based composite material as described in claim 1 or 2.

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