Preparation method of aluminum-based macromolecular cross composite material

Abstract

The invention provides a preparation method of an aluminum-based polymer cross composite material, and relates to the technical field of polymer composites.The preparation method comprises the steps that a foamed aluminum particle raw material with high porosity is subjected to surface modification treatment, and a porous aluminum matrix is obtained; carrying out gradient dispersion compounding on the modified epoxy resin, the porous aluminum matrix and the reinforced phase material to obtain a mixture; performing fiber-oriented magnetic field induction and segmented vacuum impregnation on the mixture to obtain a pre-cured material; and carrying out stepped curing molding on the pre-cured material to obtain the aluminum-based high-molecular cross composite material. According to the preparation method provided by the invention, the performance contradiction among light weight, high strength and high toughness is broken through, three-dimensional network synergistic reinforcement of a carbon hollow sphere reinforced phase and a fiber reinforced phase is realized, and effective transfer of multi-scale interface stress under low density is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer composite materials, in particular to a method for preparing an aluminum-based polymer cross-composite material. Background Art

[0002] Aluminum-based composites are a new type of composite material made from aluminum and its alloys, reinforced with fibers, whiskers, ceramic particles, and graphene, processed through a specific process. They combine the advantages of aluminum-based materials, such as low density, corrosion resistance, low thermal expansion coefficient, and good mechanical properties, while effectively addressing the inherent low strength, low hardness, and poor fatigue resistance of aluminum-based materials.

[0003] Traditional aluminum-based composite materials have a density of ≤1.0g / cm 3 When the porosity is high, the compressive strength is generally lower than 80MPa and the tensile strength is less than 60MPa; moreover, the mixed system of hollow spheres and fibers is prone to cause interfacial stress concentration (SEM shows that the pore filling rate is less than 75%); high porosity and high strength are difficult to be compatible (the strength drops sharply when the porosity is greater than 70%). Summary of the Invention

[0004] In view of the shortcomings of the prior art described above, the purpose of the present invention is to provide a method for preparing an aluminum-based polymer cross-composite material, which is used to solve the problems in the prior art that the tensile and compressive strength of aluminum-based composite materials are insufficient under low-density conditions, the hollow sphere and fiber mixed system is prone to cause interfacial stress concentration, and high porosity and high strength are difficult to be compatible.

[0005] To achieve the above-mentioned purpose and other related purposes, the present invention provides a method for preparing an aluminum-based polymer cross-composite material, comprising: performing surface modification treatment on a high-porosity foam aluminum particle raw material to obtain a porous aluminum matrix; performing gradient dispersion compounding of a modified epoxy resin with the porous aluminum matrix and a reinforcing phase material to obtain a mixture; performing magnetic field induction and segmented vacuum impregnation on the mixture for fiber orientation to obtain a precured material; and performing step-curing molding on the precured material to obtain an aluminum-based polymer cross-composite material.

[0006] In one embodiment of the present invention, a high-porosity foam aluminum particle raw material is surface-modified to obtain a porous aluminum matrix, including: treating the high-porosity foam aluminum particle raw material through a combined process of alkali washing and acid etching to obtain spare aluminum particles with a rough surface etching degree; and coating the spare aluminum particles with a titanate ethanol solution to modify the surface of the spare aluminum particles to obtain a porous aluminum matrix.

[0007] In one embodiment of the present invention, a raw material of foamed aluminum particles with high porosity is treated by a combined process of alkali washing and acid etching to obtain spare aluminum particles with a rough surface etching degree, including: alkali washing the raw material of foamed aluminum particles with high porosity with NaOH; after the alkali washing treatment, acid etching with HCl is performed to obtain spare aluminum particles with a rough surface etching degree within a set etching depth.

[0008] In one embodiment of the present invention, in the process of gradient dispersion compounding of modified epoxy resin with porous aluminum matrix and reinforcing phase material to obtain a mixture, the reinforcing phase material is prepared by: silane coupling and chopped carbon fiber to obtain modified carbon fiber as carbon fiber reinforcing phase; silane coupling treatment is performed on glass fiber to obtain modified glass fiber as glass fiber reinforcing phase; carbon hollow sphere reinforcing phase, carbon fiber reinforcing phase and glass fiber reinforcing phase are used as reinforcing phase materials.

[0009] In one embodiment of the present invention, carbon fibers are subjected to silane coupling and chopped to obtain modified carbon fibers as a carbon fiber reinforcement phase, comprising: mixing and hydrolyzing KH-550 accounting for a first preset percentage of the carbon fiber mass with an ethanol solution to obtain a first KH-550 ethanol solution; spraying the first KH-550 ethanol solution on the surface of the carbon fibers to fully coat the surface of the carbon fibers, and then immersing and drying at room temperature to form Si-OC covalent bonds and Si-O-Si cross-linked networks; and chopping the Si-OC covalent bonds and the Si-O-Si cross-linked networks to obtain modified carbon fibers as a carbon fiber reinforcement phase.

[0010] In one embodiment of the present invention, a glass fiber is subjected to a silane coupling treatment to obtain a modified glass fiber as a glass fiber reinforcement phase, comprising: mixing and hydrolyzing KH-550, which accounts for a second predetermined percentage of KH-550 by mass of the glass fiber, with an ethanol solution to obtain a second KH-550 ethanol solution; spraying the second KH-550 ethanol solution on the surface of the glass fiber to fully coat the surface of the glass fiber; and immersing the treated glass fiber at room temperature and then drying the treated glass fiber to obtain a modified glass fiber having Si-O-Si covalent bonds as the glass fiber reinforcement phase.

[0011] In one embodiment of the present invention, the reinforcing phase material includes a carbon hollow sphere reinforcing phase, a carbon fiber reinforcing phase and a glass fiber reinforcing phase; the modified epoxy resin is gradiently dispersed and compounded with a porous aluminum matrix and the reinforcing phase material to obtain a mixture, including: high-speed shear mixing of the modified epoxy resin and the carbon hollow sphere reinforcing phase to obtain a first mixture; adding the porous aluminum matrix to the first mixture for high-speed shear mixing to obtain a second mixture; adding the carbon fiber reinforcing phase and the glass fiber reinforcing phase step by step to the second mixture for high-speed shear mixing to obtain a mixture.

[0012] In one embodiment of the present invention, the modified epoxy resin has a mass percentage of 45-65 wt% and a viscosity of 150-400 cP; the carbon hollow sphere reinforcement phase has a mass percentage of 5-20 wt%, a particle size of 50-200 μm, a wall thickness of 3-8 μm, and a density of 0.15 g / cm 3 The mass percentage of the carbon fiber reinforcement phase is 15-20wt%, the length is 1-3mm, and the diameter-to-thickness ratio is greater than 80; the mass percentage of the glass fiber reinforcement phase is 5-10wt%, and the diameter is 5-12μm.

[0013] In one embodiment of the present invention, the mixture is subjected to magnetic field induction and segmented vacuum impregnation for fiber orientation to obtain a precured material, including: magnetic field induction for fiber orientation of the mixture, wherein the magnetic field intensity range of the magnetic field induced fiber orientation is 0.8-1.2T, and the angular deviation of the magnetic field induced fiber orientation is less than or equal to 15°; after magnetic field induction, segmented pressure boost impregnation is performed to obtain the precured material, wherein, while performing the segmented pressure boost impregnation, segmented coordinated control of the temperature field is performed.

[0014] In one embodiment of the present invention, the pre-cured material is subjected to step-curing molding to obtain an aluminum-based polymer cross-composite material, including: the pre-cured material is subjected to step-curing molding in sequence according to different temperature and pressure steps to obtain an aluminum-based polymer cross-composite material, wherein the step-curing includes pre-curing, main curing and post-curing.

[0015] As described above, the preparation method of the aluminum-based polymer cross composite material of the present invention has the following beneficial effects: by modifying the aluminum-based surface through alkali washing combined with acid etching and plasma grafting, adopting a carbon hollow sphere reinforcement combined with a fiber multi-scale reinforcement system, combining magnetic field orientation with a low-temperature step curing process, an ultra-light and high-strength aluminum-based polymer cross composite material is prepared, achieving the goal of achieving a low density (≤1.1g / cm 3 ) conditions to achieve a double breakthrough of more than 100MPa in both compressive and tensile strength, and the material also has high specific strength (≥120MPa·cm 3 / g) and multifunctional properties, it is suitable for lightweight load-bearing components in aerospace, collision protection structures of new energy vehicles and other fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Shown is a flow chart of the preparation method of the aluminum-based polymer cross-composite material of the present invention.

[0017] Figure 2 A flow chart showing a preparation process according to an embodiment of the present invention is shown.

[0018] Figure 3 Shown is a SEM microstructure distribution diagram of the aluminum-based polymer cross-composite material prepared according to one embodiment of the present invention.

[0019] Figure 4 Shown is a comparison chart of mechanical properties tests provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0020] The following describes the embodiments of the present invention through specific examples. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following examples and the features in the examples can be combined with each other unless they conflict. It should also be understood that the terms used in the examples of the present invention are for the purpose of describing specific embodiments, not for the purpose of limiting the scope of protection of the present invention. The test methods for which specific conditions are not specified in the following examples are generally carried out under conventional conditions or under the conditions recommended by the manufacturers.

[0021] See also Figures 1 to 4 It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings in this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with the technology. They are not intended to limit the conditions under which the present invention can be implemented, and therefore have no substantive technical significance. Any structural modifications, changes in proportions, or adjustments in size, without affecting the efficacy and purpose of the present invention, should still fall within the scope of the technical contents disclosed in the present invention.

[0022] The present invention provides a preparation method of an aluminum-based polymer cross-composite material. Through the design of a porous aluminum matrix structure, the coordination of multi-scale reinforcement phases and a low-temperature gradient forming process, an ultra-light and high-strength aluminum-based polymer cross-composite material is prepared. This method breaks through the performance contradiction between light weight, high strength and high toughness, realizes the three-dimensional network synergistic reinforcement of the carbon hollow sphere reinforcement phase and the fiber reinforcement phase, ensures the effective transmission of multi-scale interface stress under low density, and is suitable for the fields of lightweight load-bearing components in aerospace, collision protection structures of new energy vehicles, etc.

[0023] Figure 1 The flow chart of the preparation method of the aluminum-based polymer cross composite material in an exemplary embodiment of the present application is shown, including steps S10 to S40. Figure 1 The technical solution of this application will be described in detail.

[0024] First, according to step S10, the surface of the high-porosity foam aluminum particle raw material is modified to obtain a porous aluminum matrix.

[0025] During the preparation of the porous aluminum matrix, the aluminum foam particles used are high-porosity aluminum foam particles. Specifically, the aluminum foam particles have a particle size range of 0.2-1.5 mm, a porosity range of 85-92%, and a pore wall thickness range of 15-40 μm.

[0026] In step S10, surface modification treatment is performed on the high-porosity foam aluminum particle raw material to obtain a porous aluminum matrix, which may further include: Step S101: treating the raw material of aluminum foam particles with high porosity by a combined process of alkali washing and acid etching to obtain spare aluminum particles with a rough surface etching degree; Step S102: The spare aluminum particles are coated with a titanate ethanol solution to modify the surface of the spare aluminum particles to obtain a porous aluminum matrix.

[0027] During the surface modification process of high-porosity aluminum foam particle raw materials, the aluminum substrate surface can be modified through alkaline washing, acid etching, and plasma grafting. Specifically, the aluminum foam particle raw materials can be treated using a combined process of alkaline washing and acid etching, and then dried at 160°C (of course, other drying temperatures are also possible) to produce spare aluminum particles with a rough surface etch. Then, titanate is dissolved in an ethanol solution to produce a titanate ethanol solution. The dried spare aluminum particles with a rough surface etch are immersed in the titanate ethanol solution, thereby coating the surface of the spare aluminum particles with the titanate ethanol solution, completing the surface modification of the spare aluminum particles and thus obtaining a porous aluminum matrix.

[0028] In step S101, a raw material of foamed aluminum particles with high porosity is treated by a combined process of alkali washing and acid etching to obtain spare aluminum particles with a rough surface etching degree, including: The high-porosity aluminum foam particle raw material is alkaline washed with NaOH; After the alkaline washing treatment, the aluminum particles are subjected to an acid etching treatment using HCl to obtain the spare aluminum particles with a surface rough etching depth within a set range.

[0029] When treating high-porosity aluminum foam particles using a combined alkaline washing and acid etching process, the particles are first alkaline washed with 5% NaOH and then acid-etched with 10% HCl. This produces aluminum particles with a surface roughness of 5-15 μm. Furthermore, the surface roughness Ra of the etched aluminum particles is within the range of 1.5-3.0 μm, and the specific surface area is increased by 50-80% compared to conventional processes.

[0030] In step S102, when the spare aluminum particles are coated with the titanate ethanol solution, a 2 wt% titanate ethanol solution can be used to coat the spare aluminum particles for 15 minutes to modify the surface of the spare aluminum particles, thereby obtaining a surface-modified porous aluminum matrix.

[0031] Next, according to step S20, the modified epoxy resin is gradient dispersed and compounded with the porous aluminum matrix and the reinforcement phase material to obtain a mixture.

[0032] After obtaining the modified porous aluminum matrix, carbon hollow sphere reinforcement combined with a fiber multi-scale reinforcement system can be used for gradient dispersion composite. The gradient dispersion composite treatment can make the material fully filled and fused to reduce porosity and material agglomeration to obtain a mixture.

[0033] In step S20, in the process of gradient dispersion compounding of the modified epoxy resin, the porous aluminum matrix, and the reinforcing phase material to obtain a mixture, the reinforcing phase material can be prepared by the following method: The carbon fibers are subjected to silane coupling and chopped to obtain modified carbon fibers as a carbon fiber reinforcement phase; The glass fiber is subjected to silane coupling treatment to obtain modified glass fiber as a glass fiber reinforcement phase; Carbon hollow sphere reinforcement phase, carbon fiber reinforcement phase and glass fiber reinforcement phase are used as reinforcement phase materials.

[0034] During the preparation of the reinforcement phase material, the carbon fibers and glass fibers must first be surface modified. Specifically, the carbon fibers are first subjected to a silane coupling treatment and then chopped to obtain chopped modified carbon fibers as the carbon fiber reinforcement phase. The glass fibers are then subjected to a silane coupling treatment to obtain modified glass fibers as the glass fiber reinforcement phase.

[0035] The carbon fibers are subjected to silane coupling and chopped to obtain modified carbon fibers as a carbon fiber reinforcement phase, which may further include: mixing KH-550 accounting for a first predetermined percentage of the mass of the carbon fibers with an ethanol solution and hydrolyzing the mixture to obtain a first KH-550 ethanol solution; The first KH-550 ethanol solution is sprayed on the surface of the carbon fiber to fully wrap the surface of the carbon fiber, and then dried after immersion treatment at room temperature to form Si-OC covalent bonds and Si-O-Si cross-linked networks; The Si-OC covalent bonds and Si-O-Si cross-linked networks are chopped to obtain modified carbon fibers as carbon fiber reinforcement phase.

[0036] Specifically, a solution can be prepared according to an ethanol:water (80:20) ratio, and KH-550 accounting for 5% of the carbon fiber mass is mixed with the ethanol solution and hydrolyzed for 30 minutes. The solvent pH is maintained between 4 and 5 to obtain a 5wt% first KH-550 ethanol solution. The 5wt% first KH-550 ethanol solution is then sprayed onto the surface of the carbon fiber to fully coat the surface of the carbon fiber. The mixture is then naturally impregnated at room temperature for 15-30 minutes, although other times are also possible. The carbon fiber treated with the first KH-550 ethanol solution is then dried at 120°C for 1-2 hours to form Si-OC covalent bonds and Si-O-Si crosslinked networks. Other drying times are also possible. Finally, the formed Si-OC covalent bonds and Si-O-Si crosslinked networks are chopped to obtain modified carbon fibers to serve as carbon fiber reinforcement phases.

[0037] In addition, the glass fiber is subjected to silane coupling treatment to obtain modified glass fiber as a glass fiber reinforcement phase, which may further include: mixing and hydrolyzing KH-550 in an amount accounting for a second predetermined percentage of the mass of the glass fiber with the ethanol solution to obtain a second KH-550 ethanol solution; The second KH-550 ethanol solution is sprayed on the surface of the glass fiber to fully cover the surface of the glass fiber, and then dried after immersion treatment at room temperature to obtain modified glass fiber with Si-O-Si covalent bonds as the glass fiber reinforcement phase.

[0038] Specifically, a solution can be prepared according to an ethanol: water (80:20) ratio, and KH-550 accounting for 5% of the mass of the glass fiber is mixed with the ethanol solution and hydrolyzed for 30 minutes. The pH of the solvent is maintained between 5 and 6 to obtain a 5wt% first KH-550 ethanol solution. The 5wt% first KH-550 ethanol solution is then sprayed on the surface of the carbon fiber to fully coat the surface of the carbon fiber. The mixture is then naturally impregnated at room temperature for 15-30 minutes. Of course, other times are also possible. The carbon fiber treated with the first KH-550 ethanol solution is then dried at 120°C for 1-2 hours to form modified carbon fibers with Si-O-Si covalent bonds to serve as the carbon fiber reinforcement phase. Of course, other drying times are also possible.

[0039] In the process of forming the carbon hollow sphere reinforcement phase, the carbon hollow sphere is oxidized by nitric acid, which can be oxidized by nitric acid with a concentration of 5 mol / L for 2 hours, so that the density of oxygen-containing functional groups on the surface of the carbon hollow sphere exceeds 5 groups / nm. 2 , achieving the regulation of the surface chemical properties of carbon hollow spheres, thereby improving their compatibility with other materials and enhancing their role in composite materials.

[0040] The reinforcement materials include hollow carbon sphere reinforcement, carbon fiber reinforcement, and glass fiber reinforcement. The carbon fiber to glass fiber length ratio ranges from 2:1 to 3:1, and the angle between the axial direction and the principal stress direction is ≤15°.

[0041] Specifically, in the reinforcement phase material, the mass percentage of the carbon hollow sphere reinforcement phase can be 5-20wt%, the particle size can be 50-200μm, the wall thickness can be 3-8μm, and the density can be 0.15g / cm 3 The carbon fiber reinforcement phase may have a mass percentage of 15-20 wt%, a length of 1-3 mm, and an aspect ratio greater than 80. The glass fiber reinforcement phase may have a mass percentage of 5-10 wt%, and a diameter of 5-12 μm.

[0042] In addition, the mass percentage of the modified epoxy resin may be 45-65 wt %, and the viscosity may be 150-400 cP.

[0043] In step S20, the modified epoxy resin is subjected to gradient dispersion compounding with the porous aluminum matrix and the reinforcement phase material to obtain a mixture, which may further include: Step S201: High-speed shear mixing of the modified epoxy resin and the carbon hollow sphere reinforcement phase to obtain a first mixture; Step S202: adding the porous aluminum matrix to the first mixture and performing high-speed shear mixing to obtain a second mixture; Step S203: adding the carbon fiber reinforcement phase and the glass fiber reinforcement phase into the second mixture step by step and performing high-speed shear mixing to obtain a mixture.

[0044] The pre-cured material can be prepared by a low-pressure infiltration compounding process. Specifically, the pre-cured material is firstly prepared by gradient dispersion compounding and then vacuum impregnation.

[0045] In the gradient dispersion compounding process, a first mixture is prepared by first high-speed shear mixing of the modified epoxy resin and the carbon hollow sphere reinforcement phase, wherein the high-speed shear mixing can be high-speed shearing at 2000 rpm for 15 minutes. Then, the modified porous aluminum matrix is ​​added to the first mixture and high-speed shear mixing is performed again to obtain a second mixture, wherein the high-speed shear mixing again can be high-speed shearing at 2000 rpm for 20 minutes. Further, carbon fiber reinforcement phase and glass fiber reinforcement phase are added step by step to obtain a mixture, and then magnetic field-induced fiber orientation is further performed.

[0046] Next, according to step S30 , the mixed material is subjected to magnetic field induction for fiber orientation and segmented vacuum impregnation to obtain a pre-cured material.

[0047] After the modified epoxy resin is gradiently dispersed and compounded with the porous aluminum matrix and the reinforcing phase material, the mixture is subjected to magnetic field induction for fiber orientation and segmented vacuum impregnation to obtain a pre-cured material with uniform dispersion, uniform distribution and sufficient cross-linking reaction.

[0048] In step S30, the mixed material is subjected to magnetic field induction for fiber orientation and segmented vacuum impregnation to obtain a pre-cured material, including: Step S301: performing magnetic field-induced fiber orientation on the mixture, so that the magnetic or magnetically treated fibers are orderly arranged along the magnetic field direction under the action of the magnetic field, thereby improving the orientation and regularity of the fibers in the mixture and enhancing the anisotropy of the composite material performance. The magnetic field intensity range for the magnetic field-induced fiber orientation is 0.8-1.2T, and the angular deviation of the magnetic field-induced fiber orientation is less than or equal to 15°; Step S302: After the magnetic field is induced, performing segmented pressure-increasing impregnation to obtain a pre-cured material, wherein, while performing the segmented pressure-increasing impregnation, the temperature field is coordinated and controlled in segments.

[0049] During the magnetic field induction and segmented vacuum impregnation process of fiber orientation of the mixture, the magnetic field induction orientation is first performed after the carbon fiber reinforcement phase and glass fiber reinforcement are added step by step to the second mixture. When the magnetic field is induced to orient the fibers, the magnetic field intensity needs to be controlled in the range of 0.8-1.2T. This intensity range can provide sufficient magnetic torque for the fibers to align along the magnetic field direction. For commonly used materials such as organic fibers, a better orientation effect can be achieved. It is necessary to control the angle deviation to be less than or equal to 15°, that is, the maximum angle between the fiber orientation direction and the magnetic field direction. This constraint can ensure that the overall arrangement of the fibers is regular and improve the consistency and reliability of material performance in applications such as composite materials. Then, after the magnetic field is induced, the segmented boost impregnation is performed, and the segmented coordinated regulation of the temperature field is performed at the same time to obtain the precured material. Specifically, the segmented boost impregnation can be a vacuum impregnation from 0.1MPa to 0.3MPa and then to 0.5MPa, and each section is kept warm for 10 minutes. Of course, other holding times can also be used. At the same time, when the temperature field is coordinated and regulated, it can be: when the staged pressure boosting impregnation is in the 0.1MPa stage, the temperature is controlled at 25°C; when the staged pressure boosting impregnation is in the 0.3MPa stage, the temperature is controlled at 45°C; when the staged pressure boosting impregnation is in the 0.5MPa stage, the temperature is controlled at 65°C.

[0050] Finally, according to step S40, the pre-cured material is subjected to step-curing molding to obtain an aluminum-based polymer cross-composite material.

[0051] By modifying the aluminum-based surface by alkaline washing combined with acid etching and plasma grafting, and then using carbon hollow sphere reinforcement combined with a fiber multi-scale reinforcement system, combined with magnetic field orientation and low-temperature step curing process, an aluminum-based polymer cross-composite material can be produced, which has the characteristics of high compressive and tensile strength at low density.

[0052] In step S40, the pre-cured material is subjected to step-curing molding to obtain an aluminum-based polymer cross-composite material, including: The pre-cured material is sequentially cured at different temperature and pressure levels to obtain an aluminum-based polymer cross-composite material. The step curing process includes pre-curing, main curing, and post-curing. During the step curing process, the step temperature ranges from 110-180°C, and the total curing time ranges from 0.5 to 2 hours.

[0053] In the process of step-curing molding of the pre-cured material, step-curing can be performed in the order of pre-curing, main curing and post-curing. Specifically, the impregnated pre-cured material is put into a press for thermosetting molding. And in the molding process, step-curing including pre-curing, main curing and post-curing is performed according to different temperature and pressure steps to complete the full curing and cross-linking reaction of the material to obtain a composite material with preset performance requirements. Among them, the pre-curing can be cured for 0.5h at 110℃, pressure 20MPa, and humidity ≤30%; the main curing can be cured for 0.5h at 160℃ and pressure 20MPa; the post-curing can be cured for 1h at 180℃ and pressure 0MPa. The density of the aluminum-based polymer cross-composite material finally obtained can be controlled at 0.95-1.1g / cm 3 , tensile strength range reaches 115-145MPa, specific modulus exceeds 25GPa·cm 3 / g.

[0054] See also Figure 2 In the process of preparing the aluminum-based polymer cross-composite material, the materials are first prepared, the epoxy resin is surface-modified, the foamed aluminum is surface-modified, the carbon fiber and the glass fiber are surface-modified, and then the modified epoxy resin is gradient-dispersed and composited with the porous aluminum matrix and the reinforcement phase material (including the carbon hollow sphere reinforcement phase, the carbon fiber reinforcement phase and the glass fiber reinforcement phase), and then the magnetic field induction and segmented vacuum impregnation of the fiber orientation are performed, and finally the step-by-step curing molding is performed, thereby obtaining the aluminum-based polymer cross-composite material of the present invention. Figure 3 The SEM microstructure distribution diagram of the aluminum-based polymer cross-composite material prepared by the preparation method of the present invention is shown.

[0055] Example 1 The raw material of high-porosity foam aluminum particles with a porosity of 88% and a particle size of 0.6 mm was treated by a combined process of alkali washing and acid etching to obtain spare aluminum particles with a rough surface etching degree; the spare aluminum particles were coated with a titanate ethanol solution to modify the surface of the spare aluminum particles to obtain a porous aluminum matrix; the modified epoxy resin and 15% carbon hollow sphere reinforcement phase were high-speed shear mixed to obtain a first mixture; the porous aluminum matrix was added to the first mixture and high-speed shear mixed to obtain a second mixture; 15% A carbon fiber reinforced phase and a 5% glass fiber reinforced phase are added step by step to the second mixture for high-speed shear mixing to obtain a mixture; the mixture is subjected to magnetic field-induced fiber orientation; after magnetic field induction, segmented pressure-elevated impregnation is performed to obtain a precured material, wherein, while the segmented pressure-elevated impregnation is performed, segmented coordinated regulation of the temperature field is performed; the precured material is subjected to step-by-step curing molding according to a curing process of 50°C / 0.2MPa×6h→80°C / 0.5MPa×3h→110°C / 1.0MPa×1h to obtain an aluminum-based polymer cross-composite material.

[0056] Among them, the test results of aluminum-based polymer cross-composite materials are: density is 1.1g / cm 3 , the tensile strength is 119.35MPa.

[0057] Example 2 The raw material of high-porosity foam aluminum particles with a porosity of 90% and a particle size of 0.3 mm was treated by a combined process of alkali washing and acid etching to obtain spare aluminum particles with a rough surface etching degree; the spare aluminum particles were coated with a titanate ethanol solution to modify the surface of the spare aluminum particles to obtain a porous aluminum matrix; the modified epoxy resin was mixed with 15% carbon hollow sphere reinforcement phase and 1.5% carbon nanotube-modified carbon hollow sphere reinforcement phase (surface growth vertical array) at high speed to obtain a first mixture; the porous aluminum matrix was added to the first mixture and mixed at high speed to obtain a second mixture; 15% A carbon fiber reinforced phase and a 5% glass fiber reinforced phase are added step by step to the second mixture for high-speed shear mixing to obtain a mixture; the mixture is subjected to magnetic field-induced fiber orientation; after magnetic field induction, segmented pressure-elevated impregnation is performed to obtain a precured material, wherein, while the segmented pressure-elevated impregnation is performed, segmented coordinated regulation of the temperature field is performed; the precured material is subjected to step-by-step curing molding according to a curing process of 50°C / 0.2MPa×6h→80°C / 0.5MPa×3h→110°C / 1.0MPa×1h to obtain an aluminum-based polymer cross-composite material.

[0058] Among them, the test results of aluminum-based polymer cross-composite materials are: density is 0.97g / cm 3 , tensile strength is 125.35MPa, and thermal conductivity is 6.8W / (m·K).

[0059] The above two examples both show that the density of the aluminum-based polymer cross-composite material is between 0.95-1.1 g / cm 3 range, and the tensile strength is within the range of 115-145MPa.

[0060] Also, see Figure 4 It can be seen that in the three groups of aluminum-based polymer cross-composite materials under different experimental conditions of the same batch of materials, when the tensile comparison test was carried out, the tensile strength range of the aluminum-based polymer cross-composite materials reached 115-145MPa, achieving a higher stability.

[0061] In summary, the present invention discloses a method for preparing an aluminum-based polymer cross-composite material, which modifies the aluminum-based surface by alkali washing combined with acid etching and plasma grafting, adopts a carbon hollow sphere reinforcement combined with a fiber multi-scale reinforcement system, combines magnetic field orientation with a low-temperature step curing process, and prepares an ultra-light and high-strength aluminum-based polymer cross-composite material. The method achieves the following results at low density (≤1.1g / cm 3 ) conditions to achieve a double breakthrough of more than 100MPa in both compressive and tensile strength, and the material also has high specific strength (≥120MPa·cm 3 / g) and multifunctional properties, making it suitable for use in lightweight load-bearing components in aerospace, collision protection structures for new energy vehicles, and other fields. Therefore, the present invention effectively overcomes the various shortcomings of the existing technology and has high industrial application value.

[0062] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. A method for preparing an aluminum-based polymer cross-composite material, characterized in that: include: The high-porosity aluminum foam particle raw material is subjected to surface modification treatment to obtain a porous aluminum matrix; Gradiently dispersing and compounding the modified epoxy resin with the porous aluminum matrix and the reinforcing phase material to obtain a mixture; performing magnetic field induction for fiber orientation and segmented vacuum impregnation on the mixture to obtain a pre-cured material; The pre-cured material is subjected to step-curing molding to obtain the aluminum-based polymer cross-composite material.

2. The method for preparing the aluminum-based polymer cross-composite material according to claim 1, characterized in that: The surface of the high-porosity aluminum foam particle raw material is modified to obtain a porous aluminum matrix, including: The raw material of foamed aluminum particles with high porosity is treated by a combined process of alkali washing and acid etching to obtain spare aluminum particles with a rough surface etching degree; The spare aluminum particles are coated with a titanate ethanol solution to modify the surface of the spare aluminum particles to obtain the porous aluminum matrix.

3. The method for preparing the aluminum-based polymer cross-composite material according to claim 2, characterized in that: The high-porosity foam aluminum particle raw material is treated by a combined process of alkali washing and acid etching to obtain spare aluminum particles with a rough surface etching degree, including: The high-porosity aluminum foam particle raw material is alkaline washed with NaOH; After the alkaline washing treatment, the spare aluminum particles are subjected to acid etching treatment with HCl to obtain the surface rough etching depth of the spare aluminum particles within a set range.

4. The method for preparing the aluminum-based polymer cross-composite material according to claim 1, characterized in that: In the process of gradient dispersion compounding of the modified epoxy resin, the porous aluminum matrix, and the reinforcing phase material to obtain a mixture, the reinforcing phase material is prepared by the following method: The carbon fibers are subjected to silane coupling and chopped to obtain modified carbon fibers as a carbon fiber reinforcement phase; The glass fiber is subjected to silane coupling treatment to obtain modified glass fiber as a glass fiber reinforcement phase; The carbon hollow sphere reinforcement phase, the carbon fiber reinforcement phase and the glass fiber reinforcement phase are used as the reinforcement phase materials.

5. The method for preparing the aluminum-based polymer cross-composite material according to claim 4, characterized in that: The carbon fibers are subjected to silane coupling and chopped to obtain modified carbon fibers as carbon fiber reinforcement phases, including: mixing KH-550 accounting for a first preset percentage of the carbon fiber mass with an ethanol solution and hydrolyzing the mixture to obtain a first KH-550 ethanol solution; Spraying the first KH-550 ethanol solution on the surface of the carbon fiber to fully wrap the surface of the carbon fiber, and then drying it after immersion treatment at room temperature to form Si-OC covalent bonds and Si-O-Si cross-linked networks; The Si-OC covalent bonds and the Si-O-Si cross-linked network are chopped to obtain the modified carbon fibers as the carbon fiber reinforcement phase.

6. The method for preparing the aluminum-based polymer cross-composite material according to claim 4, characterized in that: The glass fiber is subjected to silane coupling treatment to obtain modified glass fiber as a glass fiber reinforcement phase, including: mixing and hydrolyzing KH-550 in an amount accounting for a second preset percentage of the glass fiber mass with the ethanol solution to obtain a second KH-550 ethanol solution; The second KH-550 ethanol solution is sprayed on the surface of the glass fiber to fully cover the surface of the glass fiber, and then dried after immersion treatment at room temperature to obtain modified glass fiber with Si-O-Si covalent bonds as the glass fiber reinforcement phase.

7. The method for preparing the aluminum-based polymer cross-composite material according to claim 1, characterized in that: The reinforcement phase material includes carbon hollow sphere reinforcement phase, carbon fiber reinforcement phase and glass fiber reinforcement phase; The modified epoxy resin is subjected to gradient dispersion and compounding with the porous aluminum matrix and the reinforcing phase material to obtain a mixture, comprising: High-speed shear mixing of the modified epoxy resin and the carbon hollow sphere reinforcement phase to obtain a first mixture; adding the porous aluminum matrix to the first mixture and performing high-speed shear mixing to obtain a second mixture; The carbon fiber reinforced phase and the glass fiber reinforced phase are added step by step into the second mixture and subjected to high-speed shear mixing to obtain a mixture.

8. The method for preparing the aluminum-based polymer cross-composite material according to claim 7, characterized in that: The modified epoxy resin has a mass percentage of 45-65 wt % and a viscosity of 150-400 cP; The carbon hollow sphere reinforcement phase has a mass percentage of 5-20 wt%, a particle size of 50-200 μm, a wall thickness of 3-8 μm, and a density of 0.15 g / cm 3 ; The mass percentage of the carbon fiber reinforcement phase is 15-20wt%, the length is 1-3mm, and the diameter-to-thickness ratio is greater than 80; The glass fiber reinforcement phase has a mass percentage of 5-10 wt % and a diameter of 5-12 μm.

9. The method for preparing the aluminum-based polymer cross-composite material according to claim 1, characterized in that: The mixed material is subjected to magnetic field induction for fiber orientation and segmented vacuum impregnation to obtain a pre-cured material, comprising: Performing magnetic field-induced fiber orientation on the mixture, wherein the magnetic field intensity of the magnetic field-induced fiber orientation is in the range of 0.8-1.2 T, and the angle deviation of the magnetic field-induced fiber orientation is less than or equal to 15°; After the magnetic field induction, segmented pressure-raising impregnation is performed to obtain the pre-cured material, wherein, while the segmented pressure-raising impregnation is performed, segmented coordinated control of the temperature field is performed.

10. The method for preparing the aluminum-based polymer cross-composite material according to claim 1, characterized in that: The pre-cured material is subjected to step-curing molding to obtain the aluminum-based polymer cross-composite material, comprising: The pre-cured material is sequentially subjected to step-curing molding according to different temperature and pressure steps to obtain the aluminum-based polymer cross-composite material, wherein the step-curing includes pre-curing, main curing and post-curing.

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