Metal composite material, method for manufacturing the same, electronic device structural member, and electronic device

Abstract

The application provides a metal composite material and a preparation method thereof, an electronic device structural member and an electronic device, and aims to solve the technical problem of poor bonding force between a magnesium alloy and plastic. The metal composite material comprises a modified magnesium alloy base material and plastic. The modified magnesium alloy base material comprises a magnesium alloy base and corrosion-resistant particles. The corrosion-resistant particles are dispersed in the magnesium alloy base. Micropores and nanopores are formed on the surface of the modified magnesium alloy base material. The plastic is injection molded on the surface of the modified magnesium alloy base material, and at least part of the plastic is embedded in the micropores and nanopores.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of metal composite materials, and in particular to a metal composite material, a preparation method thereof, an electronic device structural member and an electronic device. BACKGROUND

[0002] Nano molding technology (NMT) is a process method of combining metal and plastic with nanotechnology. After the surface of the metal is treated, the plastic is directly injection molded on the surface of the metal. The key point of this process is the nano-pore treatment of the metal material, which is the most important part of the entire injection molding process.

[0003] In related technologies, plastic materials and aluminum alloy materials are usually combined through nano molding technology. Specifically, during the processing, the aluminum alloy can be treated by alkaline washing, alkaline etching, acid etching, T-liquid treatment, electrochemical corrosion, and water washing, so as to form micropores and nano-pores on the surface of the aluminum alloy. The composite material combined by plastic and aluminum alloy has been mass-produced and applied on the mobile phone frame.

[0004] Magnesium alloy is an alloy composed of magnesium and other elements. Magnesium alloy has high specific strength and large specific elastic modulus, good heat dissipation and shock absorption, and can withstand greater impact load than aluminum alloy. When applied to electronic devices, magnesium alloy has more advantages than aluminum alloy in strength and weight, and has better application prospects. However, after chemical corrosion treatment and electrochemical corrosion treatment of the surface of the magnesium alloy, the surface of the magnesium alloy forms a horn-shaped micropore, and cannot form a nano-pore, resulting in a significant decrease in the bonding force between the magnesium alloy and the plastic. How to improve the bonding force between the magnesium alloy and the plastic is a technical problem that needs to be solved in the industry. SUMMARY

[0005] The embodiments of the present application provide a metal composite material, a preparation method thereof, an electronic device structural member and an electronic device, which are used to solve the technical problem of poor bonding force between magnesium alloy and plastic.

[0006] To achieve the above-mentioned purpose, the embodiments of the present application adopt the following technical solutions:

[0007] In a first aspect, the present application provides a metal composite material, comprising: a modified magnesium alloy substrate and a plastic, the modified magnesium alloy substrate comprising a magnesium alloy matrix and corrosion-resistant particles, the corrosion-resistant particles being dispersed in the magnesium alloy matrix, and micropores and nano-pores being formed on the surface of the modified magnesium alloy substrate; the plastic is injection molded on the surface of the modified magnesium alloy substrate, and at least part of the plastic is embedded in the micropores and nano-pores.

[0008] The metal composite material of the embodiment of the present application can significantly improve the corrosion resistance of the modified magnesium alloy substrate by adding corrosion-resistant particles in the magnesium alloy substrate. In this way, micron holes and nano holes can be formed on the surface of the modified magnesium alloy substrate, thereby improving the bonding force between the plastic and the modified magnesium alloy substrate and improving the strength and other properties of the metal composite material, so that the metal composite material can be widely used in the appearance structure and built-in structure of electronic devices, which is conducive to the lightweight design of electronic devices.

[0009] In some embodiments, the corrosion-resistant particles include at least one of aluminum oxide and silicon carbide. That is, the corrosion-resistant particles include aluminum oxide, or the corrosion-resistant particles include silicon carbide, or the corrosion-resistant particles include aluminum oxide and silicon carbide. Both aluminum oxide and silicon carbide have strong corrosion resistance. Adding aluminum oxide and / or silicon carbide to the magnesium alloy substrate can improve the corrosion resistance of the modified magnesium alloy substrate, and facilitate the formation of micron holes and nano holes on the modified magnesium alloy substrate in the subsequent surface treatment process of the modified magnesium alloy substrate. At the same time, aluminum oxide and silicon carbide have high thermal conductivity and low thermal expansion coefficient, and have strong high-temperature resistance and wear resistance. The modified magnesium alloy substrate formed by mixing aluminum oxide and / or silicon carbide with the magnesium alloy substrate has the characteristics of high specific strength, high specific stiffness, and low expansion coefficient, which can effectively reduce the risk of cracking of the modified magnesium alloy substrate in subsequent processes such as forming, drilling, and milling.

[0010] In some embodiments, the corrosion-resistant particles are metal oxides.

[0011] In some embodiments, the mass fraction of the corrosion-resistant particles is greater than or equal to 5% and less than or equal to 15%. For example, the mass fraction of the corrosion-resistant particles in the modified magnesium alloy substrate is 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, etc. In the subsequent surface treatment process, on the one hand, micron holes and nano holes can be formed on the modified magnesium alloy substrate while controlling the pore size and pore ratio, and on the other hand, the hardness of the modified magnesium alloy substrate can be controlled to avoid cracking of the modified magnesium alloy substrate in subsequent processes such as forming, drilling, and milling.

[0012] In some embodiments, the micropore has a pore size greater than or equal to 1 μm and less than or equal to 10 μm. When the pore size of the micropore is less than 1 μm, the relatively large-sized reinforcing fillers such as fiber fillers in the plastic are difficult to be embedded into the micropore along with the plastic, resulting in a decrease in the strength of the portion of the plastic embedded in the micropore, which is unable to support a large enough tensile strength between the plastic and the modified magnesium alloy substrate to cause the portion of the plastic to deform or break, thereby causing the plastic body and the modified magnesium alloy substrate to be separated from each other. When the pore size of the micropore is greater than 10 μm, the internal structure of the modified magnesium alloy substrate is greatly affected, for example, some fine design structures of the metal workpiece are easily etched and broken, or a large depth of cutting and polishing is required for the surface area of the modified magnesium alloy substrate which does not need to be bonded with the plastic to obtain a smooth surface, resulting in waste of metal material and processing time, or leaving a more noticeable jagged metal-plastic bonding gap on the product, affecting the appearance of the product.

[0013] In some embodiments, the micropore has a pore size greater than or equal to 1 μm and less than or equal to 3 μm. In this way, the internal structure of the modified magnesium alloy substrate can be further affected by the micropore.

[0014] In some embodiments, the nanopore has a pore size greater than or equal to 20 nm and less than or equal to 80 nm. In this way, on the one hand, a firm gripping structure similar to the root hairs between the plastic and the earth can be formed between the plastic and the modified magnesium alloy substrate, and on the other hand, the pore shape of the micropore can be avoided from being destroyed, thereby avoiding the bonding force between the plastic and the modified magnesium alloy substrate from being weakened, avoiding the metal composite material from cracking when subjected to the impact of multiple machining processes such as cutting, punching, drilling, etc. in subsequent processes, and the cold and hot impact and reagent erosion in various chemical treatments such as chemical polishing, anodic oxidation, etc., and ensuring that the plastic in the metal composite material has a good bonding force with the modified magnesium alloy substrate.

[0015] In some embodiments, the nanopore has a pore size greater than or equal to 40 nm and less than or equal to 80 nm.

[0016] In some embodiments, at least part of the cross-sectional area of the micropore is greater than the area of the pore opening of the micropore, and the cross section of the micropore is parallel to the plane in which the pore opening is located. In this way, the micropore is in the shape of a neck, so that a tightly bonded anchor structure can be formed between the plastic and the modified magnesium alloy substrate, thereby improving the bonding force between the plastic and the modified magnesium alloy substrate.

[0017] In some embodiments, a communication hole is formed between at least part of two adjacent micropores. Specifically, there are a plurality of micropores, and at least two adjacent micropores in the plurality of micropores are communicated through the communication hole. In this way, it is beneficial to increase the bonding force between the plastic and the modified magnesium alloy substrate in subsequent processes.

[0018] In some embodiments, the plastic includes a resin body and a fibrous filler dispersed in the resin body. The addition of the fibrous filler can adjust the coefficient of thermal expansion of the plastic to match the coefficient of thermal expansion of the magnesium alloy, and can improve the dimensional stability, mechanical strength, aging resistance, thermal conductivity, appearance, and cost of the plastic.

[0019] In some embodiments, the resin body includes one or more of polybutylene terephthalate, polyphenylene sulfide, polyamide, and polyether ether ketone.

[0020] In some embodiments, the fibrous filler includes a combination of one or more of glass fiber, carbon fiber, graphite fiber, graphene fiber, boron fiber, alumina fiber, silicon carbide fiber, boron carbide fiber, boron nitride fiber, and metal fiber.

[0021] In some embodiments, the fibrous filler has a mass fraction greater than or equal to 10% and less than or equal to 50%. For example, the fibrous filler has a mass fraction of 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, etc.

[0022] In some embodiments, the fibrous filler has a mass fraction greater than or equal to 20% and less than or equal to 40%.

[0023] In some embodiments, the metal composite has a shear strength greater than or equal to 30 MPa.

[0024] In a second aspect, the present application provides a method for preparing a metal composite, including: providing a modified magnesium alloy substrate, the modified magnesium alloy substrate including a magnesium alloy base and corrosion-resistant particles dispersed in the magnesium alloy base; performing surface treatment on the modified magnesium alloy substrate to form micropores and nanopores on the surface of the modified magnesium alloy substrate; and injection molding plastic on the modified magnesium alloy substrate after the surface treatment to obtain the metal composite.

[0025] The method for preparing the metal composite according to the embodiments of the present application can significantly improve the corrosion resistance of the modified magnesium alloy substrate by adding corrosion-resistant particles to the magnesium alloy base to form the modified magnesium alloy substrate. In this way, micropores and nanopores can be formed on the surface of the modified magnesium alloy substrate during the surface treatment of the modified magnesium alloy substrate, which can improve the bonding force between the plastic and the modified magnesium alloy substrate and improve the strength and other properties of the metal composite, so that the metal composite can be widely used in appearance structural parts and built-in structural parts of electronic devices, which is conducive to the lightweight design of electronic devices.

[0026] In some embodiments, the corrosion-resistant particles include at least one of alumina and silicon carbide.

[0027] In some embodiments, the mass fraction of the corrosion-resistant particles is greater than or equal to 5% and less than or equal to 15%.

[0028] In some embodiments, the pore size of the micropores is greater than or equal to 1 μm and less than or equal to 10 μm.

[0029] In some embodiments, the pore size of the micropores is greater than or equal to 1 μm and less than or equal to 3 μm.

[0030] In some embodiments, the pore size of the nanopores is greater than or equal to 20 nm.

[0031] In some embodiments, the pore size of the nanopores is greater than or equal to 20 nm and less than or equal to 80 nm.

[0032] In some embodiments, the pore size of the nanopores is greater than or equal to 40 nm and less than or equal to 80 nm.

[0033] In some embodiments, the surface treatment of the modified magnesium alloy substrate comprises: subjecting the modified magnesium alloy substrate to a metal corrosion treatment. In this way, micropores and nanopores can be formed on the modified magnesium alloy substrate.

[0034] In some embodiments, the surface treatment of the modified magnesium alloy substrate comprises: subjecting the modified magnesium alloy substrate to an electrochemical corrosion treatment. In this way, micropores and nanopores can be formed on the modified magnesium alloy substrate.

[0035] In some embodiments, the surface treatment of the modified magnesium alloy substrate further comprises, before the electrochemical corrosion treatment of the modified magnesium alloy substrate: subjecting the modified magnesium alloy substrate to a chemical corrosion treatment. After the chemical corrosion treatment of the modified magnesium alloy substrate, micropores can be formed on the surface of the modified magnesium alloy substrate. After the electrochemical corrosion treatment of the modified magnesium alloy substrate, nanopores can be formed on the pore walls of the micropores, and the pore depth of the micropores can be deepened, the pore size of the micropores can be enlarged, and the like. In this way, the surface treatment efficiency of the modified magnesium alloy substrate can be improved, and the cost can be reduced.

[0036] In some embodiments, the electrochemical corrosion treatment of the modified magnesium alloy substrate comprises: performing a first electrochemical corrosion treatment on the modified magnesium alloy substrate, the electrolyte of the first electrochemical corrosion treatment being a weak acid solution, the pH value of the electrolyte being greater than or equal to 5 and less than or equal to 6, the current density being greater than or equal to 200 mA / cm2 and less than 300 mA / cm2, and the power-on time being less than or equal to 10 min; and performing a second electrochemical corrosion treatment on the modified magnesium alloy substrate, the electrolyte of the second electrochemical corrosion treatment being a strong alkali solution, the pH value of the electrolyte being greater than or equal to 13 and less than or equal to 14, the current density being greater than or equal to 200 mA / cm2 and less than 300 mA / cm2, and the power-on time being less than or equal to 10 min.

[0037] Thus, the method for preparing the metal composite material according to the embodiments of the present application can form nano-pores on the pore walls of the micro-pores on the modified magnesium alloy substrate, deepen the pore diameter of the micro-pores, enlarge the pore openings of the micro-pores, and form a communication hole between at least two adjacent micro-pores. The communication hole can connect the two adjacent micro-pores, which is conducive to increasing the bonding force between the plastic and the modified magnesium alloy substrate in the subsequent process.

[0038] In some embodiments, in the surface treatment of the modified magnesium alloy substrate, after the electrochemical corrosion treatment of the modified magnesium alloy substrate, the method further comprises: chemisorbing an organic compound containing active groups on the surface of the modified magnesium alloy substrate. The organic compound containing active groups can not only be chemisorbed on the surface of the modified magnesium alloy substrate, but also can be chemically crosslinked with the functional groups on the polymer chains of the plastic through the active groups thereof in the injection molding process, so that the bonding surface of the modified magnesium alloy substrate and the plastic has better bonding force and adhesion, the resistance of gas molecules and water molecules penetrating through the bonding surface is increased, and thus the air tightness and water tightness of the metal composite material are improved.

[0039] In some embodiments, the active groups of the organic compound containing active groups include one or more of amino groups, mercapto groups, carboxyl groups, epoxy groups, and isocyanate groups.

[0040] In some embodiments, the plastic comprises a resin body and a fibrous filler dispersed in the resin body. The addition of the fibrous filler can adjust the thermal expansion coefficient of the plastic, so that the thermal expansion coefficient of the plastic matches the thermal expansion coefficient of the magnesium alloy, which can improve the dimensional stability, mechanical strength, aging resistance, or thermal conductivity of the plastic, improve the appearance, reduce the cost, and the like.

[0041] In some embodiments, the resin body comprises one or more of polybutylene terephthalate, polyphenylene sulfide, polyamide, and polyether ether ketone.

[0042] In some embodiments, the fibrous filler comprises a combination of one or more of glass fibers, carbon fibers, graphite fibers, graphene fibers, boron fibers, alumina fibers, silicon carbide fibers, boron carbide fibers, boron nitride fibers, and metal fibers.

[0043] In some embodiments, the fibrous filler has a mass fraction greater than or equal to 10% and less than or equal to 50%. Exemplarily, the fibrous filler has a mass fraction of 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, etc.

[0044] In some embodiments, the fibrous filler has a mass fraction greater than or equal to 20% and less than or equal to 40%.

[0045] In some embodiments, the method for preparing the modified magnesium alloy substrate comprises: heating a magnesium alloy base to a molten state, adding nano-sized corrosion-resistant particles into the molten magnesium alloy base, and stirring uniformly to disperse the corrosion-resistant particles in the magnesium alloy base to form a modified magnesium alloy substrate raw particle; and performing a forming treatment on the modified magnesium alloy substrate raw particle to obtain the modified magnesium alloy substrate.

[0046] In some embodiments, the forming treatment on the modified magnesium alloy substrate raw particle comprises one of: a die casting forming treatment on the modified magnesium alloy substrate raw particle, a melt casting and then extrusion forming treatment on the modified magnesium alloy substrate raw particle, a forging treatment after spray deposition on the modified magnesium alloy substrate raw particle, an extrusion treatment after spray deposition on the modified magnesium alloy substrate raw particle, and a rolling treatment after spray deposition on the modified magnesium alloy substrate raw particle.

[0047] In some embodiments, at least part of the cross-sectional area of the micropore is greater than the area of the pore opening of the micropore, and the cross-section of the micropore is parallel to the plane in which the pore opening is located. In this way, the micropore is in the shape of a necking, so that a tightly bonded anchor structure can be formed between the plastic and the modified magnesium alloy substrate, thereby improving the bonding force between the plastic and the modified magnesium alloy substrate.

[0048] In some embodiments, a communication hole is formed between at least part of two adjacent micropores. Specifically, there are a plurality of micropores, and at least two adjacent micropores exist in the plurality of micropores, and the two adjacent micropores are communicated through the communication hole. In this way, it is beneficial to increase the bonding force between the plastic and the modified magnesium alloy substrate in the subsequent process.

[0049] In a third aspect, the present application provides a metal composite material prepared by the preparation method of any one of the above embodiments.

[0050] In a fourth aspect, the present application provides an electronic device structure, at least part of which is made of the metal composite material of any one of the above, or at least part of which is made of the metal composite material prepared by the preparation method of any one of the above.

[0051] In some embodiments, the electronic device structure includes at least one of a housing, a middle plate, a key, and a camera decoration ring of the electronic device.

[0052] In a fifth aspect, the present application provides an electronic device including the electronic device structure of any one of the above.

[0053] In some embodiments, the electronic device includes a screen and a housing, the housing including a frame and a back cover, and the screen and the back cover being respectively arranged on two opposite sides of the frame.

[0054] In some embodiments, the electronic device includes a middle plate, and the middle plate is arranged on an inner circumferential surface of the frame.

[0055] In some embodiments, the electronic device is a mobile phone, a tablet computer, a notebook computer, or a watch.

[0056] In a sixth aspect, the present application provides a modified magnesium alloy substrate including a magnesium alloy base and corrosion-resistant particles, and the corrosion-resistant particles are dispersed in the magnesium alloy base. The modified magnesium alloy substrate in the present application includes corrosion-resistant particles, which can significantly improve the corrosion resistance of the modified magnesium alloy substrate, and is conducive to the formation of micropores and nanopores on the surface of the modified magnesium alloy substrate during subsequent processing, thereby improving the bonding force between the plastic and the modified magnesium alloy substrate and improving the strength and other properties of the metal composite material.

[0057] In some embodiments, the corrosion-resistant particles include at least one of aluminum oxide and silicon carbide.

[0058] In some embodiments, the corrosion-resistant particles are metal oxides.

[0059] In some embodiments, the mass fraction of the corrosion-resistant particles is greater than or equal to 5% and less than or equal to 15%.

[0060] The technical effects brought by any one of the designs of the second aspect to the sixth aspect can be referred to the technical effects brought by the different designs of the first aspect, which will not be repeated here. BRIEF DESCRIPTION OF DRAWINGS

[0061] Figure 1 Process flow chart of the preparation method of the metal composite material prepared by the nano-injection molding process in the prior art;

[0062] Figure 2 Process flow chart of the preparation method of another metal composite material prepared by the nano-injection molding process in the prior art;

[0063] Figure 3 Process flow chart of the method for preparing the metal composite material provided in the application for the embodiments;

[0064] Figure 4 Schematic diagram of the internal structure of the magnesium alloy matrix in the modified magnesium alloy substrate provided in some embodiments of the application;

[0065] Figure 5 Schematic diagram of the internal structure of the modified magnesium alloy substrate provided in some embodiments of the application;

[0066] Figure 6 Process flow chart of the method for preparing the metal composite material provided in the application for the embodiments; Figure 3

[0067] Schematic diagram of the spray deposition device provided in some embodiments of the application; Figure 7

[0068] Process flow chart of the method for preparing the metal composite material provided in the application for the embodiments; Figure 8 Figure 3 Schematic diagram of the modified magnesium alloy substrate after the surface treatment in the method for preparing the metal composite material provided in the application for the embodiments;

[0069] Figure 9 Schematic diagram of the modified magnesium alloy substrate after the chemical corrosion treatment in some embodiments of the application;

[0070] Figure 10 Process flow chart of the electrochemical corrosion treatment of the modified magnesium alloy substrate after the chemical corrosion provided in some embodiments of the application;

[0071] Figure 11 Schematic diagram of the modified magnesium alloy substrate after the electrochemical corrosion treatment in some embodiments of the application;

[0072] Figure 12 Figure 3 Schematic diagram of the metal composite material prepared by the method for preparing the metal composite material provided in the application for the embodiments;

[0073] Figure 13 Process flow chart of the surface treatment of the modified magnesium alloy substrate provided in some other embodiments of the application;

[0074] Figure 14 Schematic diagram of the electronic device provided in some embodiments of the application;

[0075] Figure 15 Exploded view of the electronic device provided in the application for the embodiments. Figure 14

[0076] Reference signs:

[0077] 100, metal composite material;​​​

[0078] 11, modified magnesium alloy substrate; 11a, micropore; 11b, nanopore;

[0079] 111, magnesium alloy substrate; 111a, grain structure;

[0080] 112, corrosion-resistant particle;

[0081] 12, plastic;

[0082] 200, spray deposition device;

[0083] 21, crucible; 22, gas atomization chamber; 23, deposition chamber; 231, waste pipe; 24, stirrer; 25, flow guide nozzle; 26, substrate; 27, baffle;

[0084] 300, electronic device;

[0085] 31, screen; 311, light-transmitting cover plate; 312, display panel;

[0086] 32, housing; 321, frame; 322, back cover;

[0087] 33, main circuit board; 34, auxiliary circuit board; 35, battery; 36, key; 37, middle plate; 38, camera decoration ring; 39, camera lens. DETAILED DESCRIPTION

[0088] The technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application. In the description of the present application, unless otherwise specified, " / " represents an "or" relationship between the objects before and after the " / ", for example, A / B can represent A or B; in the present application, "and / or" is only a description of the relationship between the associated objects, which means that there can be three relationships, for example, A and / or B, which means that there are three cases of A alone, A and B together, and B alone, where A and B can be singular or plural. In the description of the present application, unless otherwise specified, "multiple" means two or more than two. "At least one of the following" or similar expressions means any combination of the items, including any combination of single or multiple items. For example, at least one of a, b, or c can mean a, b, c, a-b, a-c, b-c, or a-b-c, where a, b, and c can be single or multiple. In addition, in order to clearly describe the technical solutions of the embodiments of the present application, in the embodiments of the present application, "first", "second" and the like are used to distinguish the same items or similar items with basically the same function and effect. Those skilled in the art can understand that "first", "second" and the like do not limit the quantity and execution order, and "first", "second" and the like do not necessarily mean different. At the same time, in the embodiments of the present application, "exemplary" or "for example" means to serve as an example, illustration or description. Any embodiment or design scheme described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as more preferred or more advantageous than other embodiments or design schemes. Rather, the use of "exemplary" or "for example" is intended to present the relevant concept in a specific manner, for easy understanding.

[0089] The embodiment of the present application provides a preparation method of a metal composite material. In the preparation method of the metal composite material in the embodiment of the present application, the modified magnesium alloy base material includes corrosion-resistant particles, and the modified magnesium alloy base material has high corrosion resistance. Therefore, when the modified magnesium alloy base material is surface treated, micron holes and nano holes can be formed on the surface of the modified magnesium alloy base material, thereby improving the bonding force between the plastic and the modified magnesium alloy base material, improving the strength and other properties of the metal composite material, and making the metal composite material widely applied to appearance structural parts, built-in structural parts and the like of electronic devices, which is beneficial to the thin design of the electronic devices.

[0090] Nano molding technology (NMT) is a process method of combining metal and plastic by nano technology. The process first treats the surface of the metal, and then directly injection molds the plastic on the surface of the metal, so that the metal and the plastic can be integrally formed. This process can realize the combination or assembly of different materials without a screw, and can also be understood as a micro mortise and tenon structure. Such a process method not only can take into account the appearance and texture of the metal, but also can simplify the design of the product structure, make the product lighter, thinner, shorter and smaller, and is widely used in the appearance structure and built-in structure of electronic devices to take into account the light and thin design and appearance of the electronic device.

[0091] Aluminum alloy has the advantages of small density, high strength, and strong corrosion resistance. The metal composite material formed by combining aluminum alloy and plastic through nano injection molding process is widely used in the structure of electronic devices.

[0092] Please refer to Figure 1 , Figure 1 is a process flow chart of the preparation method of the metal composite material prepared by the nano injection molding process in the prior art. The preparation method comprises the steps of:

[0093] S101, mechanical treatment: removing the natural oxide layer on the surface of the aluminum alloy base material by mechanical treatment (such as mechanical polishing treatment);

[0094] The natural oxide layer has low adhesion to the aluminum alloy base material and poor physical and chemical properties. Removing the natural oxide layer is beneficial to improving the adhesion between the plastic and the aluminum alloy base material.

[0095] S102, oil removal pretreatment: using alkaline and / or acidic oil removal agent to remove dirt such as oil on the surface of the aluminum alloy base material at room temperature;

[0096] During the mechanical treatment of the aluminum alloy base material, a layer of dirt such as oil will inevitably adhere to the surface of the aluminum alloy base material. In order to ensure the firm combination of the aluminum alloy base material and the plastic, the dirt on the surface of the aluminum alloy base material needs to be removed.

[0097] S103, drying treatment after cleaning;

[0098] S104, chemical corrosion treatment (T treatment): corroding the surface of the aluminum alloy base material with T treatment liquid at a certain temperature and time, and then washing, baking and cooling;

[0099] Please refer to Figure 1 After the chemical corrosion treatment, micron and nano pores are formed on the surface of the aluminum alloy base material.

[0100] S105, electrochemical corrosion treatment: please refer to Figure 1After the aluminum alloy substrate is treated by the electrochemical process, more nanopores can be formed on the pore wall of the micropore and the surface of the aluminum alloy substrate.

[0101] During the electrochemical corrosion treatment process, a layer of oxide film is formed on the surface of the aluminum alloy substrate, which can react with the resin body in the plastic and also can be combined with the aluminum alloy, thereby improving the bonding force between the plastic and the aluminum alloy substrate.

[0102] S106, nano-injection treatment: please refer to Figure 1 The plastic is injected into the surface of the aluminum alloy substrate, and the plastic is embedded in the micropore and the nanopore. The plastic and the aluminum alloy substrate form a tight bonding structure, and the metal composite material of aluminum alloy and plastic is obtained.

[0103] In the preparation method, the micropores and nanopores are formed on the surface of the aluminum alloy substrate by combining chemical corrosion and electrochemical corrosion. The micropore has a pore diameter of 2-17 microns, and the nanopore has a pore diameter of 20-40 nanometers. The shear strength between the aluminum alloy substrate and the plastic is 33-37 MPa. The bonding force between the aluminum alloy substrate and the plastic is strong, and the stability is high. However, compared with magnesium alloy, the density of aluminum alloy is large, and the weight is large.

[0104] To solve the above technical problems, in some technologies, a modified magnesium alloy substrate is combined with plastic to prepare a metal composite material by a nano-injection process.

[0105] Please refer to Figure 2 , Figure 2 It is a process flow chart of a preparation method for another metal composite material prepared by a nano-injection process in the prior art. The preparation method comprises the following steps:

[0106] S201, oil removal pretreatment: under room temperature conditions, an alkaline and / or acidic oil removal agent is used to remove dirt such as oil on the surface of the modified magnesium alloy substrate;

[0107] S202, cleaning and drying treatment;

[0108] S203, chemical corrosion treatment: different concentrations of chemical corrosion liquid are used for gradient corrosion to form micropores on the surface of the modified magnesium alloy substrate;

[0109] S204, electrochemical corrosion treatment: the modified magnesium alloy substrate is treated by electrochemical corrosion;

[0110] Since the corrosion resistance of the modified magnesium alloy substrate is poor, only nanopores can be formed on the surface of the modified magnesium alloy substrate, and nanopores cannot be formed.

[0111] S205, nano-injection processing: injecting plastic into the surface of the modified magnesium alloy substrate, embedding the plastic into the micropores and nanoscale grooves, forming a close bonding structure between the plastic and the metal, and obtaining a metal composite material integrating the magnesium alloy and the plastic.

[0112] Compared with aluminum alloy, the density of magnesium alloy is small and the weight is light, which can further reduce the weight of the metal composite material. However, the standard electrode potential of magnesium is-2.37V, which is 0.7V lower than that of aluminum. The magnesium alloy is extremely easy to corrode. After chemical corrosion treatment and electrochemical corrosion treatment, only micropores and grooves can be formed on the surface of the modified magnesium alloy substrate, and nanoholes cannot be formed. This makes the bonding force data between the plastic and the modified magnesium alloy substrate fluctuate greatly and have poor stability.

[0113] In some embodiments, after chemical corrosion treatment, the pore size of the micropores on the surface of the modified magnesium alloy substrate is 2μm-8μm, and the length of the grooves is 50nm-130nm. The shear strength of the plastic and the modified magnesium alloy substrate is 20Mpa-30Mpa.

[0114] In order to improve the bonding force between the plastic and the modified magnesium alloy substrate, the application provides a preparation method of a metal composite material. Please refer to Figure 3 , Figure 3 The preparation method of the metal composite material provided by the application embodiment is shown in the process flow chart. The preparation method comprises the following steps:

[0115] S301: providing a modified magnesium alloy substrate, the modified magnesium alloy substrate comprising a magnesium alloy base and corrosion-resistant particles, the corrosion-resistant particles being dispersed in the magnesium alloy base;

[0116] S302: performing surface treatment on the modified magnesium alloy substrate to form micropores and nanoholes on the surface of the modified magnesium alloy substrate;

[0117] S303: nano-injecting plastic on the modified magnesium alloy substrate after the surface treatment to obtain a metal composite material.

[0118] Please refer to Figures 4-5 , Figure 4 The internal structure of the magnesium alloy base 111 in the modified magnesium alloy substrate 11 provided by some embodiments of the application is shown in the schematic diagram, Figure 5 The internal structure of the modified magnesium alloy substrate 11 provided by some embodiments of the application is shown in the schematic diagram.

[0119] The magnesium alloy base 111 is an alloy composed of magnesium as the base and other elements. For example, the magnesium alloy base 111 is a magnesium-aluminum alloy, a magnesium-lithium alloy, a magnesium-manganese alloy or a magnesium-zinc-zirconium alloy.

[0120] The magnesium alloy base 111 comprises a grain structure 111a, and the corrosion-resistant particles 112 are distributed in the grain structure 111a.

[0121] In some embodiments, the corrosion-resistant particles 112 include at least one of alumina and silicon carbide. That is, the corrosion-resistant particles 112 may include one of alumina or silicon carbide, or the corrosion-resistant particles 112 may include both alumina and silicon carbide. Both alumina and silicon carbide have strong corrosion resistance. Adding alumina and / or silicon carbide to the magnesium alloy matrix 111 can improve the corrosion resistance of the modified magnesium alloy substrate 11. In subsequent surface treatment processes of the modified magnesium alloy substrate 11, it is beneficial to form micron-pores and nanopores on the modified magnesium alloy substrate 11. At the same time, alumina and silicon carbide have high thermal conductivity and low coefficient of thermal expansion, and have strong high-temperature resistance and wear resistance. The modified magnesium alloy substrate formed by mixing alumina and / or silicon carbide with the magnesium alloy matrix has the characteristics of high specific strength, high specific stiffness, and low coefficient of expansion, which can effectively reduce the risk of cracking of the modified magnesium alloy substrate 11 during subsequent forming, drilling, milling and other processes.

[0122] It is understood that in other embodiments, the corrosion-resistant particles 112 may also be other metal oxides.

[0123] In some embodiments, please refer to Figure 6 , Figure 6 for Figure 3 The process flow diagram for providing the modified magnesium alloy substrate in the preparation method shown is as follows: S301: Providing a modified magnesium alloy substrate, including:

[0124] S3011: Heat the magnesium alloy matrix to a molten state, add nano-sized corrosion-resistant particles (such as alumina) to the molten magnesium alloy matrix, and stir evenly to disperse the corrosion-resistant particles in the magnesium alloy matrix, forming modified magnesium alloy substrate granules.

[0125] Specifically, corrosion-resistant particles are uniformly dispersed in the magnesium alloy matrix.

[0126] S3012: Modified magnesium alloy substrate granules are formed to obtain modified magnesium alloy substrate.

[0127] In the process of incorporating corrosion-resistant particles into the magnesium alloy matrix, in order to prevent the magnesium alloy from oxidizing and to prevent high-temperature side reactions between magnesium and corrosion-resistant particles, corrosion-resistant particles can be added to the magnesium alloy matrix under the protection of an inert gas (such as nitrogen), and the temperature of the magnesium alloy matrix is ​​controlled to be 600℃~700℃ so that the magnesium alloy matrix is ​​just in a molten state.

[0128] Based on this, in order to balance the overall strength of the modified magnesium alloy substrate and control the pore size and pore ratio formed on the surface of the modified magnesium alloy substrate in subsequent processes, corrosion-resistant particles of different sizes can be screened and incorporated into the magnesium alloy matrix in a certain proportion.

[0129] Specifically, the corrosion-resistant particles are nanoscale. Illustratively, the particle size of the corrosion-resistant particles is 300nm-500nm. In this way, when the corrosion-resistant particles are mixed with the magnesium alloy substrate, the corrosion-resistant particles can be distributed in the grain structure of the magnesium alloy substrate to form a support structure, which can improve the corrosion resistance of the modified magnesium alloy substrate, thereby facilitating the formation of micropores and nanopores on the modified magnesium alloy substrate in subsequent surface treatment processes, and facilitating the control of the pore size of the micropores and nanopores.

[0130] Further, in order to ensure that micropores and nanopores can be formed on the modified magnesium alloy substrate while controlling the pore size, the pore ratio, and avoiding the hardness of the modified magnesium alloy substrate being too large, leading to cracking of the modified magnesium alloy substrate in subsequent forming, opening, milling and other processes, the mass fraction of the corrosion-resistant particles in the modified magnesium alloy substrate is controlled to be 5%-15%. Further, the mass fraction of the corrosion-resistant particles in the modified magnesium alloy substrate is 5%-10%. It should be noted that the calculation formula of the mass fraction of the corrosion-resistant particles is: the mass of the corrosion-resistant particles / (the mass of the corrosion-resistant particles + the mass of the magnesium alloy substrate), or the calculation formula of the mass fraction of the corrosion-resistant particles is: the mass of the corrosion-resistant particles / (the total mass of the modified magnesium alloy substrate).

[0131] Illustratively, the mass fraction of the corrosion-resistant particles in the modified magnesium alloy substrate is 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, etc.

[0132] Please continue to refer to Figure 6 After the modified magnesium alloy substrate raw particles are formed, the modified magnesium alloy substrate also includes: S3012: performing forming treatment on the modified magnesium alloy substrate raw particles to obtain the modified magnesium alloy substrate.

[0133] The forming method of the modified magnesium alloy substrate raw particles includes one of: jet deposition followed by rolling forming, jet deposition followed by forging forming, jet deposition followed by extrusion forming, die casting forming, and melting followed by extrusion forming.

[0134] Please refer to Figure 7 , Figure 7 A schematic diagram of a jet deposition device 200 provided for some embodiments of the present application. The jet deposition device 200 is used to form a modified magnesium alloy substrate blank by jet deposition.

[0135] The spray deposition device 200 comprises a crucible 21, a gas atomization chamber 22 and a deposition chamber 23, and the crucible 21 is provided with a stirrer 24. The gas atomization chamber 22 is communicated with the crucible 21. Optionally, the crucible 21 is a graphite crucible, and the stirrer 24 is an electromagnetic stirrer. The deposition chamber 23 is provided with a flow guide nozzle 25, a substrate 26 and a baffle 27. The flow guide nozzle 25 is communicated with the gas atomization chamber 22, and the substrate 26 is arranged below the flow guide nozzle 25. The baffle 27 is located between the flow guide nozzle 25 and the substrate 26. The baffle 27 is used to limit the spraying range of the flow guide nozzle 25.

[0136] The gas atomization chamber 22 and the crucible 21 are respectively communicated with a gas source of inert gas (Ar).

[0137] In the preparation of the modified magnesium alloy base material blank, the magnesium alloy base is placed in the crucible 21, and the magnesium alloy base is heated under the protection of inert gas to be in a molten state. Then, nano-level corrosion-resistant particles are added into the molten magnesium alloy base, and the magnesium alloy base and the corrosion-resistant particles are uniformly mixed by the stirrer 24 to form a modified magnesium alloy base material.

[0138] The modified magnesium alloy base material enters the gas atomization chamber 22 for atomization, and the atomized particles are sprayed out of the flow guide nozzle 25 to form a particle spray flow, which is sprayed on the substrate 26 with a lower temperature. The particle spray flow is impacted, coalesced and solidified on the substrate 26 to form a modified magnesium alloy base material blank.

[0139] The deposition chamber 23 is provided with a waste pipe 231, and the waste gas and waste generated in the spray deposition process can be discharged through the waste pipe 231.

[0140] After the modified magnesium alloy base material blank is taken out of the substrate 26, the modified magnesium alloy base material blank can be forged, extruded or rolled to form a modified magnesium alloy base material. In the embodiment of the application, the aluminum alloy base material blank is formed by the spray deposition method, which can improve the uniformity of the distribution of the corrosion-resistant particles in the magnesium alloy base.

[0141] Please refer to Figure 3 , the preparation method of the metal composite material further comprises the following steps after S301: providing the modified magnesium alloy base material.

[0142] S302: performing surface treatment on the modified magnesium alloy base material to form micropores and nanopores on the surface of the modified magnesium alloy base material.

[0143] Please refer to Figure 8 , Figure 8 for Figure 3 the process flow chart of the surface treatment on the modified magnesium alloy base material in the preparation method shown in the figure. Specifically, S302: performing surface treatment on the modified magnesium alloy base material, comprising the following steps:

[0144] S3021: performing a chemical corrosion treatment on the modified magnesium alloy substrate;

[0145] S3022: performing an electrochemical corrosion treatment on the modified magnesium alloy substrate.

[0146] The "chemical corrosion" is a corrosion (oxidation) process under non-electrochemical action, usually refers to the process that the metal is oxidized and lost by direct redox reaction with the contacted substances in non-electrolyte solution and dry gas. The "electrochemical corrosion" is the corrosion generated by electrode reaction when the metal material contacts with the electrolyte solution.

[0147] Before the surface treatment of the modified magnesium alloy substrate, the modified magnesium alloy substrate can be subjected to degreasing cleaning, deoxidation and other treatments, and the specific treatment process is not particularly limited. The deoxidation treatment can be performed by immersing in a dilute acid solution or a heated alkali solution to remove the oxide film or rust spots on the surface of the modified magnesium alloy substrate, so that it is beneficial to form uniformly distributed micropores on the surface of the modified magnesium alloy substrate during the surface treatment of the modified magnesium alloy substrate.

[0148] Please refer to Figure 9 , Figure 9 For some embodiments of the present application, a structure diagram of the modified magnesium alloy substrate 11 obtained after the chemical corrosion treatment. After the chemical corrosion treatment, the surface of the modified magnesium alloy substrate 11 forms micropores 11a and a small amount of nanopores 11b.

[0149] After the chemical corrosion treatment of the modified magnesium alloy substrate 11, micropores 11a mainly formed on the surface of the modified magnesium alloy substrate 11. That is, after the chemical corrosion treatment, the holes formed on the surface of the modified magnesium alloy substrate 11 are mainly micropores 11a, and the number of nanopores 11b is small. Specifically, the pore size, pore depth, and pore ratio of the micropores 11a can be controlled by adjusting the type, composition, PH value, corrosion time, and corrosion temperature of the chemical corrosion agent.

[0150] It can be understood that in other embodiments, after the chemical corrosion treatment of the modified magnesium alloy substrate 11, only micropores 11a can be formed on the surface of the modified magnesium alloy substrate 11, and no nanopores 11b are formed.

[0151] It should be noted that the "pore size of the micropore 11a" refers to the size of the micropore 11a. The "pore depth of the micropore 11a" refers to the distance between the micropore 11a and the bottom of the micropore 11a. The "pore ratio of the micropore 11a" refers to the ratio between the total area of the micropore 11a and the surface area of the modified magnesium alloy substrate 11 without surface treatment. The pore ratio of the micropore 11a is used to characterize the density of the micropore 11a. The greater the pore ratio, the more dense the micropore 11a; the smaller the pore ratio, the more sparse the micropore 11a.

[0152] In some embodiments, the chemical etching treatment uses a mixed acid solution as the etchant, and the pH value of the etchant is 4-6. For example, the pH value of the etchant can be 4, 4.5, 5, 5.5, 6, etc. The chemical etching time is 3-30 minutes. For example, the chemical etching time can be 3 minutes, 5 minutes, 8 minutes, 10 minutes, 12 minutes, 15 minutes, 18 minutes, 20 minutes, 22 minutes, 25 minutes, 28 minutes, 30 minutes, etc. The chemical etching temperature is 40-80°C. For example, the chemical etching temperature can be 40°C, 45°C, 50°C, 55°C, 58°C, 60°C, 65°C, 70°C, 75°C, 80°C, etc. In this way, during the chemical etching treatment, on the one hand, the micropore 11a can be formed on the surface of the modified magnesium alloy substrate, and on the other hand, the surface of the modified magnesium alloy substrate 11 can be prevented from being excessively etched, so that the surface of the modified magnesium alloy substrate 11 is not excessively lowered, thereby avoiding the situation that the size of the micropore 11a at the opening is greater than the size of the micropore 11a at the bottom, i.e., the micropore 11a is trumpet-shaped, and thus the micropore 11a is necked, so that the plastic can be embedded in the micropore 11a to form an anchor structure, which is conducive to improving the bonding force between the plastic and the modified magnesium alloy substrate 11.

[0153] It should be noted that the "necked" in the present application should be understood in a broad sense, i.e., as long as at least part of the cross-sectional area of the hole changes in a decreasing trend from the bottom to the opening of the hole, the hole can be considered to be necked.

[0154] After the chemical etching treatment of the modified magnesium alloy substrate, the modified magnesium alloy substrate is subjected to an electrochemical etching treatment. After the electrochemical etching treatment, a nanopore can be formed on the wall of the micropore, and the pore depth of the micropore can be deepened, and the pore size of the micropore can be enlarged, etc. In this way, the surface treatment efficiency of the modified magnesium alloy substrate can be improved, and the processing cost can be reduced.

[0155] Specifically, in the electrochemical corrosion process, the pore size, pore depth, and pore ratio of the nanopores and the pore size, pore depth, and pore ratio of the micropores can be controlled by adjusting the composition of the electrolyte, the current-on time, and the like. It should be noted that the "pore size of the nanopores" refers to the size of the nanopore opening. The "pore depth of the nanopores" refers to the distance between the nanopore opening and the bottom of the nanopore.

[0156] To ensure the electrochemical corrosion effect, in some embodiments, the electrochemical corrosion treatment of the modified magnesium alloy substrate includes multiple electrochemical corrosion treatments of the modified magnesium alloy substrate. "Multiple" in the present application refers to two or more times.

[0157] For example, in some embodiments, the corrosion-resistant particles are aluminum oxide. Please refer to Figure 10 , Figure 10 A flowchart of the electrochemical corrosion treatment of the modified magnesium alloy substrate is provided for some embodiments of the present application. S3022: The electrochemical corrosion treatment of the modified magnesium alloy substrate includes:

[0158] S3022a: The first electrochemical corrosion treatment of the modified magnesium alloy substrate, the electrolyte of the first electrochemical corrosion treatment has a pH value greater than or equal to 5 and less than or equal to 6, a current density greater than or equal to 200 mA / cm 2 and less than 300 mA / cm 2 , and a current-on time less than or equal to 10 min.

[0159] That is, the electrolyte of the first electrochemical corrosion treatment is a weak acid solution.

[0160] S3022b: The second electrochemical corrosion treatment of the modified magnesium alloy substrate, the electrolyte of the second electrochemical corrosion treatment has a pH value greater than or equal to 13 and less than or equal to 14, a current density greater than or equal to 200 mA / cm 2 and less than 300 mA / cm 2 , and a current-on time less than or equal to 10 min.

[0161] That is, the electrolyte of the second electrochemical corrosion treatment is a strong alkali solution.

[0162] Please refer to Figure 11 , Figure 11 A structural schematic diagram of the modified magnesium alloy substrate 11 obtained after the electrochemical corrosion treatment in some embodiments of the present application. As can be seen from Figure 10 , after the electrochemical corrosion treatment, nanopores 11b are formed on the pore wall of the micropores 11a, and compared with the modified magnesium alloy substrate 11 after the chemical corrosion treatment in Figure 9 , the micropore opening of the micropores 11a is expanded and the pore depth is deepened.

[0163] In addition, please refer to Figure 11 The wall surface between at least two adjacent micropores 11a forms a communication hole 11c for communicating the adjacent two micropores 11a. In this way, the interior of the adjacent two micropores 11a can be communicated through the communication hole 11c, and the micropore 11a can be ensured to be in a conical shape, so that the plastic can form a tightly bonded anchor structure with the modified magnesium alloy substrate 11, avoid the plastic from being pulled out of the micropore 11a, and improve the bonding force between the plastic and the modified magnesium alloy substrate 11.

[0164] In some embodiments, the area of at least part of the cross section of the micropore 11a is larger than the area of the micropore 11a, and the cross section of the micropore 11a is parallel to the plane where the micropore 11a is located. In this way, the micropore can be in a conical shape, so that the plastic can form a tightly bonded anchor structure with the modified magnesium alloy substrate 11, and thus the bonding force between the plastic and the modified magnesium alloy substrate 11 can be improved.

[0165] Further, in the direction from the micropore 11a to the bottom of the micropore 11a, the cross-sectional area of the micropore 11a gradually increases. In this way, the plastic can be prevented from being pulled out of the micropore 11a, and the bonding force between the plastic and the modified magnesium alloy substrate 11 can be further improved.

[0166] In this way, the preparation method of the metal composite material of the embodiment of the present application can form a conical nano-pore 11b on the wall of the micropore on the modified magnesium alloy substrate 11 by adjusting the composition of the electrolyte, the power-on time, etc. On the other hand, the pore diameter of the micropore 11a can be deepened, the micropore 11a can be enlarged, and a communication hole 11c can be formed between at least two adjacent micropores 11a. The communication hole 11c can communicate the adjacent two micropores 11a, which is beneficial to increasing the bonding force between the plastic and the modified magnesium alloy substrate 11 in the subsequent process.

[0167] It can be understood that in other embodiments, the communication hole 11c can also be formed between at least two adjacent micropores 11a after the chemical etching treatment of the modified magnesium alloy substrate 11.

[0168] In some embodiments, the micropores have a pore size of 1-10 μm. That is, the micropores have a pore size greater than or equal to 1 μm and less than or equal to 10 μm. When the pore size of the micropores is less than 1 μm, relatively large-sized reinforcing fillers such as fiber fillers in the plastic are difficult to embed into the micropores along with the plastic, resulting in a decrease in the strength of the portion of the plastic embedded in the micropores, which is unable to support a large enough tensile strength between the plastic and the modified magnesium alloy substrate to cause the portion of the plastic to deform or break, thereby causing the plastic body and the modified magnesium alloy substrate to separate from each other. When the pore size of the micropores is greater than 10 μm, the internal structure of the modified magnesium alloy substrate is greatly affected, for example, certain fine design structures of the metal workpiece are easily etched and broken, or a large depth of cutting and polishing is required for surface regions of the modified magnesium alloy substrate that do not need to be bonded with the plastic to obtain a smooth surface, resulting in waste of metal material and processing time, or leaving a noticeable jagged metal-plastic bonding gap on the product, affecting the appearance of the product.

[0169] Further, the micropores have a pore size of 1-3 μm. In this way, the micropores can further avoid affecting the internal structure of the modified magnesium alloy substrate.

[0170] In some embodiments, the nanopores have a pore size less than or equal to 80 nm. Further, the nanopores have a pore size greater than or equal to 20 nm and less than or equal to 80 nm. Still further, the nanopores have a pore size greater than or equal to 40 nm and less than or equal to 80 nm. In this way, on the one hand, a firm gripping structure similar to the roots of plants and the ground between the plastic and the modified magnesium alloy substrate can be formed, and on the other hand, the pore-like morphology of the micropores can be avoided from being destroyed, so that the bonding force between the plastic and the modified magnesium alloy substrate can be avoided from being weakened, so that the modified magnesium alloy substrate can be avoided from being impacted by multiple machining processes such as cutting, punching, drilling, and the like in subsequent processes, and the cold and hot shocks and chemical erosion in multiple chemical treatments such as chemical polishing, anodic oxidation, and the like, so that the plastic and the modified magnesium alloy substrate in the metal composite material have a good bonding force.

[0171] It can be understood that in other embodiments, the electrochemical etching treatment of the modified magnesium alloy substrate can further include three, four, or more electrochemical etching treatments.

[0172] In the present embodiment, the modified magnesium alloy substrate is subjected to a chemical etching treatment before being subjected to the electrochemical etching, so that the effect of the surface treatment can be improved, the micropores and nanopores can be formed on the surface of the modified magnesium alloy substrate, and the efficiency of the surface treatment can be improved. In other embodiments, the modified magnesium alloy substrate can be directly subjected to the electrochemical etching without being subjected to the chemical etching treatment.

[0173] Since the modified magnesium alloy substrate in the embodiment of the present application includes corrosion-resistant particles, the corrosion resistance of the modified magnesium alloy substrate can be significantly improved, so that after surface treatment of the modified magnesium alloy substrate, micron pores and nanopores can be formed on the modified magnesium alloy substrate. Thus, in the injection molding process, plastic can be injected into the micron pores and nanopores, so that a firm gripping structure similar to that between plant roots and the earth is formed between the plastic and the modified magnesium alloy substrate, which can withstand the impact of multiple machining processes such as cutting, punching, drilling, etc. in subsequent processes, as well as the cold and hot impact and reagent erosion in various chemical treatments such as chemical polishing, anodic oxidation, etc. Thus, the plastic and the modified magnesium alloy substrate in the metal composite have good bonding force, so that the metal composite prepared by the preparation method can be applied to the appearance structure and built-in structure of electronic devices, and can balance the light and thin design of electronic devices and the appearance aesthetic performance of electronic devices.

[0174] Please refer to Figure 3 , the preparation method of the metal composite further comprises: S303: injection molding plastic on the modified magnesium alloy substrate after surface treatment to obtain a metal composite. Specifically, nano-injection molding plastic on the modified magnesium alloy substrate after surface treatment to obtain a metal composite.

[0175] Please refer to Figure 12 , Figure 12 The metal composite 100 prepared by the preparation method shown in Figure 3 . As can be seen from Figure 12 , after nano-injection molding plastic 12 on the modified magnesium alloy substrate 11 after surface treatment, the plastic 12 is embedded in the micron pores 11a and nanopores 11b, and a firm gripping structure similar to that between plant roots and the earth is formed between the plastic 12 and the modified magnesium alloy substrate 11, improving the bonding force between the plastic 12 and the modified magnesium alloy substrate 11, and further improving the strength of the metal composite 100.

[0176] Specifically, during injection molding, one or more modified magnesium alloy substrates after surface treatment can be placed in the mold cavity, the mold is closed, the plastic particles enter the barrel through the hopper of the injection molding machine, are heated and melted in the barrel, and are injected into the mold cavity through the nozzle under the propelling action of the high-speed rotating screw, fill the remaining space in the mold cavity and contact the surface of the modified magnesium alloy substrate, further injecting into the micron pores and nanopores of the modified magnesium alloy substrate, and then hardening through cooling, opening the mold and demolding, to obtain a tightly bonded composite of the modified magnesium alloy substrate and the plastic (i.e. metal composite).

[0177] The main conditions of injection molding include mold temperature, barrel temperature, nozzle temperature, injection pressure, injection speed, holding pressure, holding time, and cooling time. The conditions of injection molding vary according to the type of plastic and are not particularly limited. In actual injection molding, the conditions of injection molding need to be repeatedly tested and fine-tuned to obtain the optimal conditions. Under the optimal conditions, the plastic inside the product is dense, the surface is smooth, there are no defects, and the bonding force between the modified magnesium alloy substrate and the plastic is high.

[0178] In addition, in order to improve the bonding force between the modified magnesium alloy substrate and the plastic, the modified magnesium alloy substrate is preferably preheated before injection molding, and the modified magnesium alloy substrate is preferably heated to a temperature close to the mold temperature during preheating. After injection molding is completed, the product can also be annealed as needed, that is, the metal composite material is kept at a certain temperature for a period of time to eliminate residual stress.

[0179] After injection molding is completed, the metal composite material can also be subjected to physical processing such as cutting, punching, and drilling, and chemical surface treatment such as chemical polishing, anodizing, and dyeing, which will not be described one by one here.

[0180] In some embodiments, the plastic includes a resin body and a fibrous filler dispersed in the resin body. The addition of the fibrous filler can adjust the thermal expansion coefficient of the plastic, match the thermal expansion coefficient of the plastic with the thermal expansion coefficient of the magnesium alloy, improve the dimensional stability, mechanical strength, aging resistance, or thermal conductivity of the plastic, improve the appearance, and reduce the cost.

[0181] Optionally, the mass fraction of the fibrous filler is 10% to 50%. That is, the mass fraction of the fibrous filler is greater than or equal to 10% and less than or equal to 50%. The calculation formula of the mass fraction of the fibrous filler is: the mass of the fibrous filler / the total mass of the plastic. Exemplarily, the mass fraction of the fibrous filler is 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, etc.

[0182] In some embodiments, the resin body includes a combination of one or more of polybutylene terephthalate (PBT), polyphenylene sulfide (PPS), polyether ether ketone (PEEK), and polyamide (PA). That is, the resin body can include one of PBT, PPS, PEEK, and PA, or the resin body can include a combination of two, three, or four of PBT, PPS, PEEK, and PA.

[0183] The fibrous filler includes one or more of a combination of glass fibers, carbon fibers, graphite fibers, graphene fibers, boron fibers, aluminum oxide fibers, silicon carbide fibers, boron carbide fibers, boron nitride fibers, and metal fibers.

[0184] The method for preparing the plastic in the present application is not particularly limited, as long as the components in the plastic can be uniformly mixed.

[0185] In some embodiments, the surface treatment of the modified magnesium alloy substrate includes: Figure 13 , Figure 13 A process flow diagram for surface treatment of a modified magnesium alloy substrate is provided for some embodiments of the present application. The difference between the method for surface treatment of the modified magnesium alloy substrate in the present embodiment and the method for surface treatment of the modified magnesium alloy substrate in any of the above embodiments is that, in the surface treatment of the modified magnesium alloy substrate in the present embodiment, after the electrochemical corrosion treatment of the modified magnesium alloy substrate, it further includes: chemisorption of an organic compound containing active groups on the surface of the modified magnesium alloy substrate.

[0186] For example, in some embodiments, S302, the surface treatment of the modified magnesium alloy substrate includes:

[0187] S3021, chemical corrosion treatment of the modified magnesium alloy substrate;

[0188] S3022, electrochemical corrosion treatment of the modified magnesium alloy substrate;

[0189] S3023, chemisorption of an organic compound containing active groups on the surface of the modified magnesium alloy substrate.

[0190] The active group in the embodiments of the present application refers to a group that can undergo a chemical crosslinking reaction with the polymer chain of the plastic. The type of chemical crosslinking reaction can be addition reaction, substitution reaction, polycondensation reaction, esterification reaction, acylation reaction, ester exchange reaction, amine exchange reaction, etc., and is not particularly limited.

[0191] In some embodiments, the active group of the organic compound containing active groups is one or more of a combination of amino, mercapto, carboxyl, epoxy, isocyanate groups. Alternatively, the amino group can be primary amino, secondary amino or tertiary amino.

[0192] In addition to being able to chemisorb on the surface of the modified magnesium alloy substrate, the organic compound containing active groups can also undergo a chemical crosslinking reaction between its active group and the functional group on the polymer chain of the plastic during the injection molding process, so that the bonding surface of the modified magnesium alloy substrate and the plastic has better bonding force and adhesion, increases the resistance of gas molecules and water molecules penetrating from the bonding surface, thereby improving the air tightness and water tightness of the metal composite material.

[0193] Specifically, the active group-containing organic compound is chemisorbed to the modified magnesium alloy substrate surface in a manner of forming a covalent bond and / or a coordination bond. Illustratively, the active group-containing organic compound is chemisorbed to the modified magnesium alloy substrate surface through a combination of one or more of an amino group, a mercapto group, a carboxyl group, a methoxysilane group (-Si-OCH3), and an ethoxysilane group (-Si-O-C2H5).

[0194] The N, S, and O atoms in the amino group, the mercapto group, and the carboxyl group have lone pairs of electrons, which endow the polar groups with electron-donating ability, and are prone to form coordination bonds with metal atoms or metal ions having empty orbits to be chemisorbed. In addition, the metal surface layer is easily oxidized to form metal oxides in air, and further reacts with water vapor in the air to form hydroxyl groups. Therefore, hydroxyl groups exist on the metal surface. The methoxysilane group and the ethoxysilane group are easily hydrolyzed to form silanol groups in the presence of water or water vapor, which are prone to combine with the hydroxyl groups on the metal surface and dehydrate to form new covalent bonds and be chemisorbed on the metal surface. Compared with hydrogen bonds and van der Waals forces, the covalent bonds and the coordination bonds (the coordination bond itself belongs to a special covalent bond) have strong bond energies, which can effectively improve the bonding force and adhesion between the metal and the plastic.

[0195] The method for adsorbing the active group-containing organic compound on the metal surface can be to evaporate the active group-containing organic compound directly on the metal surface, or to prepare a solution of the active group-containing organic compound and then adsorb the solution on the metal surface by dipping, brushing, spraying, or spraying. The solvent component can be selected from a combination of one or more of water, alcohols, alcohol ethers, ether esters, ethers, ketones, and various solvents, as long as it is beneficial to infiltrate the modified magnesium alloy substrate surface and does not chemically react with the active group-containing organic compound.

[0196] The preparation method of the metal composite material in the embodiments of the present application will be described below in conjunction with specific examples.

[0197] Example 1

[0198] The preparation method of the metal composite material in the embodiments of the present application includes:

[0199] Step 1: providing a modified magnesium alloy substrate (i.e., preparing a modified magnesium alloy substrate):

[0200] The α-phase alumina particles with a particle size of 300 nm to 500 nm are baked at 500°C to 600°C for 1 h to 2 h to remove the moisture of the alumina particles;

[0201] The magnesium alloy substrate is heated in a graphite crucible, and the heating temperature is 600°C to 700°C, so that the magnesium alloy substrate is just in a molten state;

[0202] The nano-sized alumina particles are added into the molten magnesium alloy matrix under the protection of inert gas nitrogen, and are stirred and mixed uniformly to obtain the modified magnesium alloy matrix raw particles, wherein the adding rate of the nano-sized alumina particles is 1 g / min to 1.5 g / min, and the mass fraction of the nano-sized alumina particles is 5% to 15%;

[0203] The modified magnesium alloy matrix raw particles enter the atomization chamber of the spray deposition device, and are atomized in the atomization chamber under the protection of inert gas nitrogen, and the atomization gas pressure is 0.5 MPa to 0.9 MPa;

[0204] The atomized modified magnesium alloy matrix raw particles are sprayed out through the flow guide nozzle, and are sprayed into small droplets to fall on the substrate about 700 mm away from the nozzle to form the modified magnesium alloy matrix blank;

[0205] The obtained modified magnesium alloy matrix blank is subjected to hot extrusion treatment to eliminate the stress of the blank: the extrusion mandrel is conical, the reverse extrusion mode is adopted, the extrusion ratio is about 9:1, and the extrusion temperature is 300-350℃;

[0206] The modified magnesium alloy matrix blank is subjected to rolling treatment to obtain the modified magnesium alloy matrix: the rolling temperature is 300℃ to 400℃, so that the rolled plate can be completely recrystallized, and the grain refinement effect is obvious; the rolling speed is 10 m / min to 20 m / min, so that the alloy structure is uniform, the grains are all equiaxed grains, and the stress of the modified magnesium alloy matrix can be further eliminated.

[0207] Step two: surface treatment is performed on the modified magnesium alloy matrix to form micropores and nanopores on the surface of the modified magnesium alloy matrix:

[0208] The alkaline cleaning removes the oil stains on the surface of the modified magnesium alloy matrix, and after water washing, the modified magnesium alloy matrix is dried at 120℃ to 140℃ for 10 min;

[0209] The modified magnesium alloy matrix is subjected to chemical corrosion treatment: the PH of the mixed acid solution is 4 to 6, the corrosion time is 3 min to 30 min, and the corrosion temperature is 40 to 80℃; after the chemical corrosion treatment, micropores are mainly formed on the surface of the modified magnesium alloy matrix;

[0210] The modified magnesium alloy matrix after the water washing chemical corrosion treatment is dried at 120℃ to 140℃ for 10 min;

[0211] First electrochemical corrosion treatment of the modified magnesium alloy substrate: the modified magnesium alloy substrate as anode, graphite as cathode, electrolyte is a mixed solution of phosphoric acid (H3PO4) with a concentration of 75% and sulfuric acid (H2SO4) with a concentration of 10%, the PH value of the electrolyte is 6, the temperature of the electrolyte is controlled at 25℃, the anodic oxidation current density is 200mA / cm 2 ~300mA / cm 2 , the anodic oxidation time is 0~10min, the pulse voltage frequency is 5Hz~30Hz;

[0212] Water washing of the modified magnesium alloy substrate after the first electrochemical corrosion treatment, and baking at 120℃~140℃ for 10min;

[0213] Second electrochemical corrosion treatment of the modified magnesium alloy substrate: the modified magnesium alloy substrate as anode, graphite as cathode, electrolyte is NaOH solution, the PH value of the electrolyte is 13~14, the temperature of the electrolyte is controlled at 25℃, the anodic oxidation current density is 200mA / cm 2 ~300mA / cm 2 , the anodic oxidation time is 0~10min, the pulse voltage frequency is 5Hz~30Hz; in this step, the second electrochemical corrosion of the modified magnesium alloy substrate is carried out with strong alkali as electrolyte, which can deepen the size of nano-pores;

[0214] Water washing of the modified magnesium alloy substrate after the second electrochemical corrosion treatment, and baking at 120℃~140℃ for 10min.

[0215] Step three: CNC treatment of the modified magnesium alloy substrate obtained in step two to remove the excess of the modified magnesium alloy substrate;

[0216] Step four: nano-injection treatment of the modified magnesium alloy substrate:

[0217] The nano-injected plastic includes PPS resin main body and 20%~40% fibrous filler, the material temperature is 270℃~350℃, the mold temperature is 140℃~160℃, the holding pressure is 80MPa~100MPa, the holding time is 3s, the injection pressure is 170MPa~190MPa, and the injection speed is 400mm / s~900mm / s.

[0218] Cooling treatment of the metal composite material obtained by injection molding;

[0219] Annealing treatment of the metal composite material after cooling treatment: baking at 120℃ for 2 hours.

[0220] The metal composite prepared by the above preparation method is observed under a scanning electron microscope (SEM), and it can be seen that the surface of the metal composite forms micropores with a pore size of 1 um to 3 um and nanopores with a pore size of 40 nm to 80 nm. Moreover, the shear strength of the metal composite is not less than 30 MPa, which is comparable to the shear strength of an aluminum alloy-based composite.

[0221] Embodiment 2

[0222] The preparation method of the metal composite in the embodiment of the present application is basically the same as the preparation method of the metal composite in Embodiment 1, except that the modified magnesium alloy substrate in the embodiment is processed by a die casting forming process.

[0223] Embodiment 3

[0224] The preparation method of the metal composite in the embodiment of the present application is basically the same as the preparation method of the metal composite in Embodiment 1, except that the modified magnesium alloy substrate in the embodiment is processed by an extrusion forming process.

[0225] The embodiment of the present application also provides a metal composite 100. The metal composite 100 in the embodiment can be prepared by the above preparation method of the metal composite 100, or can be prepared by other preparation methods.

[0226] The metal composite 100 in the embodiment of the present application has the same structure as the metal composite 100 prepared by the preparation method of the metal composite 100 in the above embodiments. Specifically, refer to Figure 12 The metal composite 100 includes a modified magnesium alloy substrate 11 and a plastic 12. The modified magnesium alloy substrate 11 includes a magnesium alloy base 111 and corrosion-resistant particles 112, and the corrosion-resistant particles 112 are dispersed in the magnesium alloy base 111. The modified magnesium alloy substrate 11 forms micropores 11a and nanopores 11b thereon. The plastic 12 is injection molded on the surface of the modified magnesium alloy substrate 11, and the plastic 12 is embedded in the nanopores 11b and the micropores 11a.

[0227] The metal composite material 100 in the embodiments of the present application, the modified magnesium alloy substrate 11 includes a corrosion-resistant material, the modified magnesium alloy substrate 11 has strong corrosion resistance, and in the processing process, the modified magnesium alloy substrate 11 is beneficial to forming micropores 11a and nanopores 11b on the surface of the modified magnesium alloy substrate 11, thereby improving the bonding force between the plastic 12 and the modified magnesium alloy substrate 11, improving the strength and other properties of the metal composite material 100, and enabling the modified magnesium alloy substrate 11 to be widely applied to appearance structural parts (such as a shell) and built-in structural parts (such as a middle plate) of electronic devices, thereby facilitating the lightweight design of the electronic devices. The embodiments of the present application also provide an electronic device, which includes but is not limited to a mobile phone, a tablet personal computer, a laptop computer, a personal digital assistant (PDA), a personal computer, a notebook computer, a vehicle-mounted device, a wearable device (such as a watch), and the like. The embodiments of the present application do not specially limit the specific form of the electronic device.

[0228] Please refer to Figure 14 and Figure 15 , Figure 14 a structural schematic diagram of an electronic device 300 provided by some embodiments of the present application, Figure 15 for Figure 14 an exploded view of the electronic device 300. In the embodiment, the electronic device 300 is a phablet. Specifically, the electronic device 300 includes a screen 31, a shell 32, a main circuit board 33, a secondary circuit board 34, and a battery 35.

[0229] The screen 31 is used to display images, videos, and the like. The screen 31 can include a light-transmitting cover plate 311 and a display panel 312. The light-transmitting cover plate 311 and the display panel 312 are arranged in layers and fixedly connected. The light-transmitting cover plate 311 is mainly used to protect and prevent dust from the display panel 312.

[0230] The shell 32 includes a frame 321 and a back cover 322, and the frame 321 is arranged around the outer edge of the back cover 322. The light-transmitting cover plate 311 and the back cover 322 are respectively connected to the opposite sides of the frame 321, and the light-transmitting cover plate 311, the frame 321, and the back cover 322 enclose a receiving space. The display panel 312, the main circuit board 33, the secondary circuit board 34, the battery 35, and the like of the electronic device 300 are arranged in the receiving space.

[0231] In some embodiments, the frame 321 is provided with a slot, a hole or other structure for mounting a volume control key, a power key or other key 36. The back cover 322 is provided with a camera decoration ring 38 for providing a channel for a camera inside the electronic device 300 to collect light. The camera decoration ring 38 is provided with a camera lens 39 for protecting the camera and preventing dust or water from entering the electronic device 300.

[0232] In some embodiments, referring to Figure 15 , the electronic device 300 further includes a middle plate 37. The middle plate 37 is fixed around the inner surface of the frame 321. For example, the middle plate 37 can be fixed to the frame 321 by welding, or the middle plate 37 can be integrally formed with the frame 321. The middle plate 37 serves as a structural "skeleton" of the electronic device 300. The main circuit board 33, the auxiliary circuit board 34 and the battery 35 can be fixed to the middle plate 37 by screwing, clamping, welding or other methods.

[0233] It should be noted that the middle plate 37 and the outer shell 32 of the present application can be understood as electronic device structural members. Of course, the protruding structures such as the key 36 and the camera decoration ring 38 on the outer surface of the electronic device 300 can also be understood as electronic device structural members.

[0234] At least part of the material of the electronic device structural member is the above-mentioned metal composite material. That is, at least part of the electronic device structural member is processed from the above-mentioned metal composite material. In this way, the structural strength of the outer shell 32 can be ensured while the electronic device 300 is thinned.

[0235] Specifically, in some embodiments, at least part of the material of the outer shell 32 is the above-mentioned metal composite material. That is, at least part of the outer shell 32 is processed from the above-mentioned metal composite material. In this way, the structural strength of the outer shell 32 can be ensured while the electronic device 300 is thinned.

[0236] In some embodiments, at least part of the material of the middle plate 37 is the above-mentioned metal composite material. That is, at least part of the middle plate 37 is processed from the above-mentioned metal composite material. In this way, the weight of the electronic device 300 can be further reduced.

[0237] In other embodiments, the key 36, the camera decoration ring 38 and other electronic device structural members of the electronic device 300 can also be processed from the above-mentioned metal composite material.

[0238] The electronic device 300 of the present application is processed from the above-mentioned metal composite material, and the structural strength of the electronic device structural member can be ensured while the electronic device 300 is thinned.

[0239] In the description of the present specification, specific features, structures, materials or characteristics can be combined in any one or more embodiments or examples in a suitable manner.

[0240] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A metal composite, characterized by, The application relates to a metal composite material, which comprises: a modified magnesium alloy substrate, the modified magnesium alloy substrate comprising a magnesium alloy base and corrosion-resistant particles, the corrosion-resistant particles being dispersed in the magnesium alloy base, micropores and nanopores being formed on the surface of the modified magnesium alloy substrate; plastic, the plastic being injection molded on the surface of the modified magnesium alloy substrate, and at least part of the plastic being embedded in the micropores and the nanopores; the micropores have a pore diameter greater than or equal to 1 mu m and less than or equal to 10 mu m, and the nanopores have a pore diameter greater than or equal to 20 nm and less than or equal to 80 nm.

2. The metal composite of claim 1, wherein The corrosion-resistant particles comprise at least one of alumina and silicon carbide.

3. The metal composite of claim 1, wherein The mass fraction of the corrosion-resistant particles is greater than or equal to 5% and less than or equal to 15%.

4. The metal composite of claim 1, wherein The nanopores have a pore diameter greater than or equal to 40 nm and less than or equal to 80 nm.

5. The metal composite of claim 1, wherein The micropores have a pore diameter greater than or equal to 1 mu m and less than or equal to 3 mu m.

6. The metal composite of any one of claims 1-5, wherein, At least part of the cross-sectional area of the micropores is greater than the area of the pore opening of the micropores, and the cross section of the micropores is parallel to the plane in which the pore opening is located.

7. The metal composite of any one of claims 1-5, wherein, A communication hole is formed between at least part of two adjacent micropores.

8. The metal composite of any one of claims 1-5, wherein, The plastic comprises a resin body and a fibrous filler, and the fibrous filler is dispersed in the resin body.

9. The metal composite of claim 8, wherein, The mass fraction of the fibrous filler is greater than or equal to 10% and less than or equal to 50%.

10. A method of producing the metal composite according to any one of claims 1 to 9, characterized by, The application also relates to a preparation method of the metal composite material. The application provides a modified magnesium alloy substrate, the modified magnesium alloy substrate comprising a magnesium alloy base and corrosion-resistant particles, the corrosion-resistant particles being dispersed in the magnesium alloy base; the modified magnesium alloy substrate is subjected to surface treatment to form micropores and nanopores on the surface of the modified magnesium alloy substrate; the plastic is injection molded on the modified magnesium alloy substrate after the surface treatment, so that the metal composite material is obtained.

11. The method of claim 10, wherein, The surface treatment of the modified magnesium alloy substrate comprises: The surface treatment of the modified magnesium alloy substrate comprises:

12. The method of claim 11, wherein, The surface treatment of the modified magnesium alloy substrate comprises: the modified magnesium alloy substrate is subjected to a first electrochemical corrosion treatment, the electrolyte of which has a pH value greater than or equal to 5 and less than or equal to 6, a current density greater than or equal to 200 mA / cm 2 and less than 300 mA / cm 2 and a power-on time less than or equal to 10 min; the modified magnesium alloy substrate is subjected to a second electrochemical corrosion treatment, the electrolyte of which has a pH value greater than or equal to 13 and less than or equal to 14, a current density greater than or equal to 200 mA / cm 2 and less than 300 mA / cm 2 , and an electric current application time less than or equal to 10 min.

13. The production method according to claim 11 or 12, characterized by, In the surface treatment of the modified magnesium alloy substrate, before the electrochemical corrosion treatment of the modified magnesium alloy substrate, the surface treatment of the modified magnesium alloy substrate further comprises chemical corrosion treatment of the modified magnesium alloy substrate.

14. The production method according to any one of claims 10 to 12, characterized by, In the surface treatment of the modified magnesium alloy substrate, after the electrochemical corrosion treatment of the modified magnesium alloy substrate, the surface treatment of the modified magnesium alloy substrate further comprises: The surface of the modified magnesium alloy substrate is chemisorbed with an organic compound containing active groups.

15. The method of claim 14, wherein: The active groups of the organic compound containing active groups comprise one or more of amino groups, mercapto groups, carboxyl groups, epoxy groups and isocyanate groups.

16. The method of manufacturing according to any one of claims 10-12, 15, wherein, The application provides a modified magnesium alloy substrate, the modified magnesium alloy substrate comprising a magnesium alloy base and corrosion-resistant particles, the corrosion-resistant particles being dispersed in the magnesium alloy base; The magnesium alloy base is heated to a molten state, the nano-sized corrosion-resistant particles are added into the molten magnesium alloy base, and the corrosion-resistant particles are uniformly stirred and dispersed in the magnesium alloy base to form a modified magnesium alloy substrate original particle; The modified magnesium alloy substrate original particle is subjected to forming treatment, so that the modified magnesium alloy substrate is obtained.

17. The method of claim 16, wherein, The forming treatment of the modified magnesium alloy base material raw particles includes one of die casting forming treatment, extrusion forming treatment after melting and casting, forging treatment after spray deposition, extrusion treatment after spray deposition, and rolling treatment after spray deposition.

18. An electronic device structure, comprising: At least part of the electronic device structure is made of the metal composite material according to any one of claims 1-9, or at least part of the electronic device structure is made of the metal composite material prepared by the preparation method according to any one of claims 10-17.

19. The electronic device structure of claim 18, wherein, The electronic device structure includes at least one of a shell, a middle plate, a key, and a camera decoration ring of an electronic device.

20. An electronic device, comprising: The electronic device structure includes the electronic device structure according to claim 18 or 19.

21. A modified magnesium alloy substrate, characterized in that, The magnesium alloy base material includes a magnesium alloy base and corrosion-resistant particles, and the corrosion-resistant particles are dispersed in the magnesium alloy base. Micropores and nanopores are formed on the surface of the modified magnesium alloy base material, the micropores have a pore diameter greater than or equal to 1 μm and less than or equal to 10 μm, and the nanopores have a pore diameter greater than or equal to 20 nm and less than or equal to 80 nm.

Images