A magnesium-based composite panel with light weight and high heat dissipation, and a preparation method and application thereof

Abstract

The application discloses a magnesium-based composite plate with light weight and high heat dissipation efficiency and a preparation method and application thereof. The magnesium-based composite plate comprises a substrate layer, a panel layer and a transition layer, the panel layer is arranged on the upper and lower sides of the substrate layer, the transition layer is arranged between the substrate layer and the panel layer, the substrate layer, the transition layer and the panel layer are integrally formed through heat pressing and curing, the substrate layer is made of a panel structure of a magnesium alloy material, the panel layer is made of a panel structure of a light metal material, and the transition layer is made of a composite combined layer structure of a heat conducting material and the substrate layer and the panel layer through melting. The magnesium-based composite plate prepared by the method can be widely applied to electronic equipment, aerospace equipment, power equipment or precision equipment, so that the product obtained through processing is not only beautiful in appearance, but also light in weight, thin in thickness, high in strength, good in corrosion resistance and heat dissipation performance, and can meet the use performance requirements of the product.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of mobile phone middle frame, and particularly relates to a magnesium-based composite plate with light weight and high heat dissipation efficiency as well as a preparation method and application thereof. BACKGROUND

[0002] With the continuous progress and development of science and technology, people's requirements for electronic products such as mobile phones are getting higher and higher. Not only are electronic devices for the purpose of communication, but also are multimedia mobile phones integrating music, video, photography, and Internet functions. With the continuous development of the mobile phone industry, the performance of mobile phones is becoming more and more powerful, especially the resolution and size of processors and screens are constantly improving. With the gradual trend of large screens, thinness, and multi-functionality of smart phones, the continuous growth of mainstream screen sizes requires higher strength mobile phone middle frames to support. Currently, the commonly used smart phones have a serious heating phenomenon during long-term use.

[0003] The mobile phone middle frame is an important component of the mobile phone, and the aesthetic level of the mobile phone middle frame largely determines the purchasing desire of consumers. Due to the advantages of high strength, good texture, and good heat dissipation, traditional mobile phones made of plastic materials have been gradually replaced by metal mobile phones. Since the mobile phone middle frame is the skeleton of the mobile phone and is used to support the entire mobile phone, the mobile phone middle frame, as an important component for connecting the middle plate and the back cover, is also gradually being metalized. The metalized middle frame not only has a beautiful appearance, but also has the characteristics of wear resistance, drop resistance, and corrosion resistance. The currently used metalized mobile phone middle frame is mainly made of aluminum alloy, titanium alloy, and stainless steel. The existing metalized mobile phone middle frame has the problem of poor heat dissipation during long-term use. When the temperature of the mobile phone is too high and cannot be dissipated, the service life and performance of the internal parts of the mobile phone are affected.

[0004] Since the magnesium alloy is an alloy composed of magnesium as a base material and other elements, it has the characteristics of: low density (1.8 g / cm 3 left and right), high specific strength, large specific elastic modulus, good heat dissipation, good shock absorption, and greater impact load capacity than aluminum alloy. Since magnesium is the lightest metal among practical metals, the specific gravity of magnesium is about 2 / 3 of that of aluminum and 1 / 4 of that of iron. Due to the low density, good specific performance, good shock absorption, and good electrical and thermal conductivity of magnesium alloy, it has good process performance. However, it has the disadvantages of poor corrosion resistance, easy oxidation and combustion, and poor heat resistance, so it is prone to oxidation and combustion during processing, and it is inconvenient to process.

[0005] Through retrieval, the patent document with the application publication number CN118241059A discloses a high-strength 7-series aluminum alloy profile and a manufacturing method and application thereof, the patent document with the application publication number CN110743957A discloses a magnesium alloy hollow four-layer structure low-temperature forming / high-temperature reaction diffusion connection integrated forming method, and the patent document with the application publication number CN118250364A discloses a titanium-aluminum composite mobile phone middle frame and a preparation process thereof. It can be known from the three patent documents retrieved that the problems of meeting the light weight and poor heat dissipation performance of the mobile phone middle frame are provided from different angles. In order to obtain a mobile phone middle frame with lighter weight, thinner thickness, higher strength and excellent heat dissipation performance in order to meet market demand, it is an urgent problem to be solved at present, and it is very necessary to provide a magnesium-based composite plate different from the magnesium-based composite plate disclosed in the prior art. SUMMARY

[0006] In order to solve the problems of the existing magnesium alloy, such as large activity, easy oxidation on the surface and difficult to eliminate, and poor diffusion connection performance of the magnesium alloy, a magnesium-based composite plate and a preparation method are provided. The magnesium-based composite plate prepared by the method not only meets the requirements of light weight, thin thickness, high strength and excellent heat dissipation performance, but also is convenient for later processing, thereby effectively solving the problem that the magnesium alloy is easy to produce oxidation and combustion during processing. Specifically, the magnesium-based composite plate and the preparation method and application thereof are provided.

[0007] To solve the above technical problems, the technical scheme adopted by the present application is as follows: a magnesium-based composite plate with light weight and high heat dissipation efficiency, the magnesium-based composite plate comprises a substrate layer, a panel layer and a transition layer, the panel layer is arranged on the upper and lower sides of the substrate layer, and the transition layer is arranged between the substrate layer and the panel layer, the substrate layer, the transition layer and the panel layer are formed into an integrated laminated structure by hot pressing and curing, wherein the substrate layer is made of a panel structure made of a magnesium alloy material, the panel layer is made of a panel structure made of a light metal material, and the transition layer is a composite bonding layer structure made of a heat-conducting material and the substrate layer and the panel layer.

[0008] Further, the magnesium-based composite plate with light weight and high heat dissipation efficiency comprises any one of pure copper material, copper alloy material, pure aluminum material or aluminum alloy material as the light metal material, and any one of ceramic fiber, metal fiber or carbon fiber as the heat-conducting material, wherein the ceramic fiber is any one of aluminum silicate fiber, aluminum oxide fiber, mullite fiber, silicon carbide fiber or quartz fiber, the metal fiber is copper fiber with high thermal conductivity, and the carbon fiber is heat-conducting carbon fiber or PBO fiber.

[0009] The present application also provides a preparation method of the magnesium-based composite plate, which comprises the following steps:

[0010] S1. According to the shape and structure of the magnesium-based composite plate prepared as needed, a metal mold corresponding to the magnesium-based composite plate is selected, and the metal mold is required to have an outer dimension larger than that of the magnesium-based composite plate by 0.5-2.5 mm;

[0011] S2. A panel structure made of a magnesium alloy material is selected as a substrate layer, and a panel structure made of a pure copper material or a copper alloy material is selected as a panel layer, and a heat-conducting material is prepared as a spare part;

[0012] S3. One of the panel layers is first placed in the metal mold, and then the heat-conducting material is uniformly placed on the panel layer, and then the substrate layer is placed on the heat-conducting material, and then the heat-conducting material is uniformly placed on the substrate layer in the same way, and then the other panel layer is placed on the heat-conducting material to form a green body, and finally the green body is subjected to a sealing treatment;

[0013] S4. The sealed metal mold is preheated, and at the same time, a vacuumizing treatment is performed during the heating process;

[0014] S5. The metal mold subjected to the vacuumizing treatment is subjected to a hot-pressing treatment in a hot-pressing device, and the heat-conducting material is fused and formed into an integrated body with the substrate layer and the panel layer to form an integrated composite laminated structure;

[0015] S6. The metal mold subjected to the hot-pressing treatment is taken out of the hot-pressing device, and after being cooled to room temperature, the metal mold is disassembled to obtain a magnesium-based composite plate having a desired shape and size.

[0016] Further, in the step S3 of the preparation method, a release agent is provided in the metal mold in advance before the panel layer is placed in the metal mold, the release agent is graphite, and the thickness of the release agent is 0.5-1.5 mm.

[0017] Further, in the step S3 of the preparation method, the sealing treatment is to seal the laminated green body in the metal mold.

[0018] Further, in the step S4 of the preparation method, the preheating temperature is 200-300℃, and the specific process conditions of the vacuumizing treatment are as follows: the degassing temperature is 200-300℃, the vacuum degree is 1X10 -1 ~1X10 -3 Pa, and the degassing time is 5-15 hours.

[0019] Further, in the step S5, the hot pressing treatment is hot isostatic pressing treatment or electromagnetic induction heating treatment, wherein, in the hot isostatic pressing treatment, the vacuumized metal mold is placed in a hot isostatic pressing machine for hot isostatic pressing treatment; and in the electromagnetic induction heating treatment, the vacuumized metal mold is placed in an electromagnetic induction heater for electromagnetic induction heating treatment; wherein, in the hot isostatic pressing treatment, the specific process conditions are: hot isostatic pressing temperature is 450-500 DEG C, pressure is 80-150 MPa, and holding time is 3-5 hours; and in the electromagnetic induction heating treatment, the specific process conditions are: heating temperature is 450-500 DEG C, pressure is 80-150 MPa, and holding time is 2-3 hours.

[0020] Further, in the preparation method, the thickness of the substrate layer is 15-25 mm, the thickness of the panel layer is 1-5 mm, and the thickness of the transition layer is 5-10 mm.

[0021] The application further discloses application of the magnesium-based composite board in electronic equipment, aerospace equipment, power equipment or precision equipment.

[0022] Further, the electronic equipment includes a mobile phone, a computer, a watch, a camera or a smart wearable device, is used for preparing a mobile phone frame or a support framework of the computer, the watch, the camera or the smart wearable device; the aerospace equipment includes an aerospace structural part, is used for preparing an outer frame or a support framework of the aerospace structural part; the power equipment includes a measuring table and a power supply device, is used for preparing an outer frame of the measuring table or a support framework of the power supply device; and the precision equipment includes a precision measurement or detection instrument, is used for preparing an outer frame or a support framework of the precision measurement or detection instrument.

[0023] Compared with the prior art, the magnesium-based composite board, the preparation method and the application have the following beneficial effects:

[0024] (1) The magnesium-based composite board prepared by the method has the characteristics of light weight, thin thickness, high strength, good corrosion resistance and excellent heat dissipation performance, and has good processing surface ductility, small hardness and good subsequent processing performance, thereby effectively reducing the processing cost.

[0025] (2) The magnesium-based composite board prepared by the method has the characteristics of light weight, thin thickness, high strength, good corrosion resistance and excellent heat dissipation performance, and has good processing surface ductility, small hardness and good subsequent processing performance, thereby effectively reducing the processing cost.

[0026] (3) The magnesium-based composite board described in the present application is made by setting a layer of heat-conducting material between the base plate layer and the panel layer, which is fused between the base plate layer and the panel layer during the hot-pressing process to form a transition layer, thereby enhancing the composite firmness and strength of the magnesium-based composite board; the transition layer formed by hot-pressing can effectively buffer most of the internal stress generated in the cooling process due to the different thermal expansion coefficients of the base plate layer and the panel layer, so that the composite structure is not prone to deformation or has a lighter degree of deformation.

[0027] (4) The magnesium-based composite board described in the present application uses a panel structure made of magnesium alloy material as the base plate layer, and a panel structure made of pure copper material or copper alloy material as the panel layer, and the transition layer is a composite bonding layer formed by fusing the heat-conducting material with the base plate layer and the panel layer, thereby making the magnesium-based composite board have small internal stress, good ductility, and not prone to deformation or cracking, and finally taking advantage of the good ductility and low hardness of the panel layer, the subsequent processing is facilitated, and the processing cost can be effectively reduced.

[0028] In summary, the magnesium-based composite board prepared by the method described in the present application can be widely used in electronic equipment, aerospace equipment, power equipment or precision equipment, and when the magnesium-based composite board is used as a base material for processing related products, it has the advantages of stable processing technology, high production efficiency, short processing time and low production cost, and the processed products not only have an attractive appearance, but also have light weight, thin thickness, high strength, good corrosion resistance and heat dissipation performance, which can meet the performance requirements of the products. BRIEF DESCRIPTION OF DRAWINGS

[0029] The present application will be further described in detail below with reference to the accompanying drawings.

[0030] Figure 1 is a structural schematic diagram of the magnesium-based composite board described in the present application.

[0031] In the figure: 1 - base plate layer, 2 - panel layer, 3 - transition layer. DETAILED DESCRIPTION

[0032] The embodiments of the present application will be described below by specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in the present specification.

[0033] It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings are merely for illustrative purposes to aid those skilled in the art and to facilitate understanding. They are not intended to limit the scope of the invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness or purpose of the invention, should still fall within the scope of the disclosed technical content. Furthermore, the terms "upper," "lower," "left," and "right" used in this specification are merely for clarity and not intended to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention's implementation.

[0034] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connection" and "provided with" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0035] It should be noted that the term "comprising" or any other variation is intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Example 1

[0036] like Figure 1 As shown, this embodiment provides a lightweight and efficient heat dissipation magnesium-based composite board. The magnesium-based composite board includes a substrate layer 1, a panel layer 2, and a transition layer 3. The panel layer 2 is provided on the upper and lower sides of the substrate layer 1, and the transition layer 3 is provided between the substrate layer 1 and the panel layer 2. The substrate layer 1, the transition layer 3, and the panel layer 2 are hot-pressed and cured into an integral composite laminate structure. The substrate layer 1 is a panel structure made of magnesium alloy material, the panel layer 2 is a panel structure made of aluminum alloy material, and the transition layer 3 is a composite bonding layer structure formed by melting a thermally conductive material with the substrate layer 1 and the panel layer 2. The thermally conductive material is ceramic fiber, and the ceramic fiber is silicon carbide fiber.

[0037] The present invention also provides a method for preparing the above-mentioned magnesium-based composite plate, the method comprising the following steps:

[0038] S1. According to the shape and structure of the magnesium-based composite plate prepared as needed, a metal mold corresponding to the magnesium-based composite plate is selected, and the metal mold is required to have an outer dimension larger than the magnesium-based composite plate by 0.5-2.5 mm;

[0039] S2. A panel structure made of a magnesium alloy material is selected as the substrate layer 1, and a panel structure made of pure copper material is selected as the panel layer 2, the thickness of the substrate layer 1 is 15 mm, the thickness of the panel layer 2 is 2 mm, and the thickness of the transition layer is 5 mm.

[0040] S3. A layer of release agent with a thickness of 0.5-1.0 mm is arranged in the metal mold in advance, the release agent is graphite, one of the panel layers 2 is placed in the metal mold first, then the heat-conducting material is uniformly placed on the panel layer 2, then the substrate layer 1 is placed on the heat-conducting material, then the heat-conducting material is uniformly placed on the substrate layer 1 in the same way, then the other panel layer 2 is placed on the heat-conducting material to form a green body, and finally the green body is subjected to a sealing treatment, that is, the layered green body is placed in the metal mold for sealing;

[0041] S4. The sealed metal mold is preheated, and at the same time, a vacuumizing treatment is performed during the heating process; the preheating temperature is 200-300℃, and the specific process conditions of the vacuumizing treatment are as follows: the degassing temperature is 200-250℃, the vacuum degree is 1X10 -1 Pa, and the degassing time is 10-15 hours;

[0042] S5. The metal mold after the vacuumizing treatment is subjected to a hot-pressing treatment in a hot-pressing equipment, the heat-conducting material is fused and formed into an integrated body with the substrate layer 1 and the panel layer 2 through hot-pressing solidification to form an integrated composite layered structure; the hot-pressing treatment is a hot isostatic pressing treatment, and the hot isostatic pressing treatment mode is that the metal mold after the vacuumizing treatment is placed in a hot isostatic pressing machine for hot isostatic pressing treatment, and the specific process conditions are as follows: the hot isostatic pressing temperature is 480-500℃, the pressure is 80 MPa, and the holding time is 3-4 hours;

[0043] S6. The metal mold after the hot-pressing treatment is taken out of the hot-pressing equipment, cooled to room temperature, and then disassembled to obtain a magnesium-based composite plate with a required shape and size.

[0044] The magnesium-based composite plate after processing is subjected to destructive analysis, since the transition layer 3 is arranged between the substrate layer 1 and the panel layer 2, the heat-conducting material is used to absorb the internal stress generated due to the different thermal expansion coefficients of the substrate layer 1 and the panel layer 2 during the forming and cooling process to reduce the deformation, the transition layer 3 is used to make the substrate layer 1 and the panel layer 2 into an integrated composite layered structure through hot-pressing solidification, and finally the transition layer 3 in the middle does not produce separation and delamination through a bending and extrusion test. Example 2

[0045] The embodiment is basically the same as the embodiment 1, the difference is that the panel layer 2 uses a panel structure made of pure aluminum material, and the heat-conducting material used in the transition layer 3 uses metal fibers, and the metal fibers use copper fibers.

[0046] The preparation method of the magnesium-based composite board in this embodiment is the same as that in embodiment 1.

[0047] The magnesium-based composite board after processing is subjected to destructive analysis. Since the transition layer 3 is provided between the substrate layer 1 and the panel layer 2, the heat-conducting material is used to absorb the internal stress generated due to the difference in thermal expansion coefficient between the substrate layer 1 and the panel layer 2 during the forming and cooling process, so as to reduce the deformation. The transition layer 3 makes the substrate layer 1 and the panel layer 2 into an integrated composite laminated structure through heat pressing and curing. Finally, through the bending and extrusion test, the transition layer 3 in the middle does not produce delamination. Example 3

[0048] As shown in Figure 1 The magnesium-based composite board provided by the embodiment has light weight and high heat dissipation efficiency. The magnesium-based composite board includes a substrate layer 1, a panel layer 2 and a transition layer 3. The panel layer 2 is provided on the upper and lower sides of the substrate layer 1, and the transition layer 3 is provided between the substrate layer 1 and the panel layer 2. The substrate layer 1, the transition layer 3 and the panel layer 2 are formed into an integrated composite laminated structure through heat pressing and curing. The substrate layer 1 is a panel structure made of magnesium alloy material. The panel layer 2 is a panel structure made of copper alloy material. The transition layer 3 is a composite combined layer structure formed by melting the heat-conducting material and the substrate layer 1 and the panel layer 2. The heat-conducting material is carbon fiber, and the carbon fiber is heat-conducting carbon fiber.

[0049] S1. According to the shape and structure of the magnesium-based composite board to be prepared, select a metal mold corresponding thereto, and require that the outer dimension of the metal mold is 0.5-2.5mm larger than the size of the magnesium-based composite board;

[0050] S2. Select a panel structure made of magnesium alloy material as the substrate layer 1, and select a panel structure made of pure copper material or copper alloy material as the panel layer 2. The thickness of the substrate layer 1 is 20mm, the thickness of the panel layer 2 is 1mm, and the thickness of the transition layer is 8mm. At the same time, heat-conducting materials are prepared for standby;

[0051] S3. A layer of release agent with a thickness of 0.8-1.2 mm is arranged in the metal mold in advance, the release agent is graphite, one of the panel layers 2 is placed in the metal mold first, then the heat-conducting material is evenly placed on the panel layer 2, then the substrate layer 1 is placed on the heat-conducting material, then the heat-conducting material is evenly placed on the substrate layer 1 in the same way, then the other panel layer 2 is placed on the heat-conducting material, to form a green body, and finally the green body is subjected to a sealing treatment, the sealing treatment is to place the stacked green body into the metal mold for sealing;

[0052] S4. The sealed metal mold is preheated, and at the same time, a vacuumizing treatment is performed during the heating process; the preheating temperature is 200-300°C, and the specific process conditions of the vacuumizing treatment are as follows: the degassing temperature is 240-280°C, the vacuum degree is 1X10 -2 Pa, and the degassing time is 8-12 hours.

[0053] S5. The metal mold after the vacuumizing treatment is subjected to a hot-pressing treatment in a hot-pressing equipment, the heat-conducting material is fused and formed into an integrated structure with the substrate layer 1 and the panel layer 2 through the hot-pressing solidification, to form an integrated composite laminated structure; the hot-pressing treatment is an electromagnetic induction heating treatment, and the electromagnetic induction heating treatment mode is to place the metal mold after the vacuumizing treatment into an electromagnetic induction heater for electromagnetic induction heating treatment; the specific process conditions are as follows: the heating temperature is 480°C, the pressure is 100 MPa, and the holding time is 2.5 hours.

[0054] S6. The metal mold after the hot-pressing treatment is taken out of the hot-pressing equipment, and after being cooled to room temperature, the metal mold is disassembled, to obtain a magnesium-based composite plate with a required shape and size.

[0055] The magnesium-based composite plate after processing is subjected to destructive analysis, since the transition layer 3 is arranged between the substrate layer 1 and the panel layer 2, the heat-conducting material is used to absorb the internal stress generated due to the different thermal expansion coefficients of the substrate layer 1 and the panel layer 2 during the forming and cooling process, to reduce the deformation, the transition layer 3 is used to make the substrate layer 1 and the panel layer 2 into an integrated composite laminated structure through the hot-pressing solidification, and finally the transition layer 3 in the middle does not produce the separation and delamination through the bending and extrusion test. Example 4

[0056] As Figure 1As shown, the embodiment provides a magnesium-based composite panel with light weight and high heat dissipation, which comprises a substrate layer 1, a panel layer 2 and a transition layer 3, the panel layer 2 is arranged on the upper and lower sides of the substrate layer 1 respectively, and the transition layer 3 is arranged between the substrate layer 1 and the panel layer 2, the substrate layer 1, the transition layer 3 and the panel layer 2 are formed into an integrated composite laminated structure by hot pressing and curing, wherein the substrate layer 1 is a panel structure made of magnesium alloy material, the panel layer 2 is a panel structure made of pure copper material, and the transition layer 3 is a composite bonding layer structure made of heat-conducting material and the substrate layer 1 and the panel layer 2 by melting, the heat-conducting material is carbon fiber, and the carbon fiber is PBO fiber.

[0057] The embodiment also provides a preparation method of the magnesium-based composite panel, which comprises the following steps:

[0058] S1. According to the shape and structure of the magnesium-based composite panel to be prepared, a metal mold corresponding to the magnesium-based composite panel is selected, and the metal mold has an outer size larger than the magnesium-based composite panel by 0.5-2.5 mm;

[0059] S2. A panel structure made of magnesium alloy material is selected as the substrate layer 1, and a panel structure made of pure copper material or copper alloy material is selected as the panel layer 2, the thickness of the substrate layer 1 is 25 mm, the thickness of the panel layer 2 is 5 mm, and the thickness of the transition layer is 10 mm, and a heat-conducting material is prepared for standby;

[0060] S3. A layer of release agent with a thickness of 1.0-1.5 mm is arranged in the metal mold in advance, the release agent is graphite, one of the panel layers 2 is placed in the metal mold, then the heat-conducting material is uniformly placed on the panel layer 2, then the substrate layer 1 is placed on the heat-conducting material, then the heat-conducting material is uniformly placed on the substrate layer 1 in the same way, then the other panel layer 2 is placed on the heat-conducting material to form a green body, and finally the green body is subjected to a sealing treatment; the sealing treatment is to seal the laminated green body in the metal mold;

[0061] S4. The sealed metal mold is preheated, and vacuumizing treatment is performed during the heating process; the preheating temperature is 200-300℃, and the specific process conditions of the vacuumizing treatment are: a degassing temperature of 250-300℃, a vacuum degree of 1X10 -3 Pa, and a degassing time of 5-10 hours.

[0062] S5. The metal mold after the vacuumizing treatment is subjected to hot pressing treatment in a hot pressing equipment, and the heat conductive material is fused and formed into an integrated structure with the substrate layer 1 and the panel layer 2 through heat pressing solidification to form an integrated composite laminated structure; the hot pressing treatment is hot isostatic pressing treatment, and the hot isostatic pressing treatment mode is that the metal mold after the vacuumizing treatment is placed in a hot isostatic pressing machine to perform hot isostatic pressing treatment, and the specific process conditions are that the hot isostatic pressing temperature is 450-480°C, the pressure is 150 MPa, and the holding time is 3-4 hours;

[0063] S6. The metal mold after the hot pressing treatment is taken out of the hot pressing equipment, and after being cooled to room temperature, the metal mold is disassembled to obtain a magnesium-based composite panel with a desired shape and size.

[0064] The magnesium-based composite panel after processing is subjected to destructive analysis, and since the transition layer 3 is arranged between the substrate layer 1 and the panel layer 2, the heat conductive material is used to absorb the internal stress generated due to the different thermal expansion coefficients of the substrate layer 1 and the panel layer 2 during the forming and cooling process to reduce deformation, the transition layer 3 is used to make the substrate layer 1 and the panel layer 2 into an integrated composite laminated structure through heat pressing solidification, and finally, the transition layer 3 in the middle does not separate and delaminate through the bending and extrusion test.

[0065] Comparative Example 1

[0066] The magnesium-based composite panel provided in the comparative example includes a substrate layer 1 and a panel layer 2.

[0067] The substrate layer 1 and the panel layer 2 in the comparative example are the same as in Example 2.

[0068] The preparation method of the magnesium-based composite panel in the comparative example is the same as in Example 1, and the substrate layer 1 and the panel layer 2 are combined together.

[0069] The magnesium-based composite panel after processing is subjected to destructive analysis, and since there is no transition layer 3 between the substrate layer 1 and the panel layer 2, but an integrated structure is directly formed through hot pressing. Finally, through the bending and extrusion test, cracks appear in the bonding part between the substrate layer 1 and the panel layer 2, and the separation and delamination occur. The direct hot pressing forming method can form an integrated structure without external force, but during long-term use or under the action of external pressure, separation and delamination will occur, which cannot meet the product use requirements.

[0070] Comparative Example 2

[0071] The magnesium-based composite panel provided in the comparative example includes a substrate layer 1 and a panel layer 2.

[0072] The substrate layer 1 and the panel layer 2 in the comparative example are the same as in Example 3.

[0073] The preparation method of the magnesium-based composite board of the comparative example is the same as that of Example 3, and the substrate layer 1 and the panel layer 2 are combined together.

[0074] The magnesium-based composite board after processing is subjected to destructive analysis. Since there is no transition layer 3 between the substrate layer 1 and the panel layer 2, but an integrated structure is formed by direct hot pressing. Finally, through the bending and extrusion test, cracks appear in the bonding part between the substrate layer 1 and the panel layer 2, and delamination occurs. The direct hot pressing forming method can form an integrated structure without external force, but delamination may occur during long-term use or under external pressure, which cannot meet the product use requirements.

[0075] As can be seen, the magnesium-based composite board prepared by the method has a transition layer 3 between the substrate layer 1 and the panel layer 2. The transition layer 3 is a composite bonding layer structure formed by melting the substrate layer 1 and the panel layer 2, and the transition layer 3 is made of any one of ceramic fiber, metal fiber or carbon fiber. Ceramic fiber has the advantages of light weight, high temperature resistance, thermal stability, low thermal conductivity and small specific heat, and is applied to the middle frame of the mobile phone. Not only can it reduce the weight, but also can enhance the strength.

[0076] Metal fiber refers to a fiber-shaped material with high metal content and continuous distribution of metal materials, and the fiber with non-continuous metal powder dispersed in organic polymer is not a metal fiber. Metal fiber is generally micron-level, and has good mechanical properties, high breaking strength and tensile modulus, and good bending resistance and toughness. Metal fiber has irregular cross-section and conventional surface area, which makes it have a very large specific surface area. The metals with high thermal conductivity mainly include copper and silver. However, the use of silver will greatly increase the cost. Therefore, the metal fiber uses copper fiber with high thermal conductivity, which can not only reduce the weight, but also greatly improve the heat dissipation performance and reduce the production cost.

[0077] The carbon fiber uses heat-conducting carbon fiber or PBO fiber. The heat-conducting carbon fiber is a high-thermal-conductivity carbon fiber material developed for thermal design. The thermal conductivity of the carbon fiber in the fiber direction can exceed that of copper, and the highest can reach 700 W / mk. At the same time, it has good mechanical properties, electrical properties and excellent heat dissipation and radiation capacity. The fibrous high-thermal-conductivity carbon powder made of such carbon fiber is fibrous in itself, and can be designed to be heat-conducting and oriented, which is the biggest difference and advantage compared with the previous carbon powder and other heat-conducting materials. It can be used in the filling of high-molecular composite materials, the development of heat-dissipation materials for electronic appliances, and the solution of heat-dissipation problems of high-density integrated electronic components and LED products. When applied to the middle frame of the mobile phone, it can not only reduce the weight, but also enhance the heat dissipation performance.

[0078] And for PBO fiber, PBO fiber is the abbreviation of poly-p-phenylene benzobisoxazole fiber, its English name is: Poly-p-phenylene benzobisoxazole, PBO fiber is a liquid crystal aromatic heterocyclic polymer, poly-p-phenylene benzobisoxazole (PB0) fiber is a new type of fiber with high strength, high modulus, high thermal stability and high chemical corrosion resistance, its main characteristics are good heat resistance, high strength and modulus, so it is widely used. In high temperature filtration, electronics and electrical, synthetic materials, safety protection, national defense and military industry, transportation, aerospace and other fields. The strength and modulus of PBO fiber are the highest among existing chemical fibers, it does not burn and shrink in flame, its heat resistance and flame resistance are higher than any other organic and inorganic fibers, its impact resistance, friction resistance and dimensional stability are very excellent, and it is light and soft, it is an ideal textile raw material. Because it has both mechanical properties and high temperature resistance, flame resistance and other two highest characteristics, it is close to ideal super fiber, and is known as the king of fiber. When it is applied to the middle frame of mobile phone, it can not only reduce the weight, but also enhance the impact resistance, thereby improving the strength.

[0079] In summary, the magnesium-based composite plate prepared by the method of the application can be widely applied to electronic equipment, aerospace equipment, power equipment or precision equipment, when the magnesium-based composite plate is used as a base material for processing related products, it has the advantages of stable processing technology, high production efficiency, short processing time and low production cost, and the processed products not only have beautiful appearance, but also have light weight, thin thickness, high strength, good corrosion resistance and heat dissipation performance, which can meet the use performance requirements of the products.

[0080] Other details of the application are well known to those skilled in the art.

[0081] The protection scope of the application is not limited to the technical solutions disclosed in the specific embodiments, the above description is only the preferred embodiment of the application, and does not limit the application, any slight modification, equivalent replacement and improvement made according to the technical solutions of the application should be included in the protection scope of the technical solutions of the application.

Claims

1. A lightweight and highly efficient heat-dissipating magnesium-based composite plate, characterized in that: The magnesium-based composite board comprises a substrate layer (1), a panel layer (2) and a transition layer (3), the panel layer (2) is arranged on both sides of the substrate layer (1), and the transition layer (3) is arranged between the substrate layer (1) and the panel layer (2), the substrate layer (1), the transition layer (3) and the panel layer (2) are formed into an integrated composite laminated structure by hot pressing and curing, wherein the substrate layer (1) is a panel structure made of magnesium alloy material, the panel layer (2) is a panel structure made of light metal material, and the transition layer (3) is a composite combined layer structure made of heat-conducting material and the substrate layer (1) and the panel layer (2) by melting; the light metal material is any one of pure copper material, copper alloy material, pure aluminum material or aluminum alloy material; the heat-conducting material is any one of ceramic fiber, metal fiber or carbon fiber, wherein the ceramic fiber is any one of aluminum silicate fiber, aluminum oxide fiber, mullite fiber, silicon carbide fiber or quartz fiber; the metal fiber is copper fiber with high thermal conductivity; and the carbon fiber is heat-conducting carbon fiber or PBO fiber; and the hot pressing in the hot pressing and curing process is hot isostatic pressing or electromagnetic induction heating, wherein in the hot isostatic pressing process, the specific process conditions are that the hot isostatic pressing temperature is 450-500 DEG C, the pressure is 80-150 MPa, and the holding time is 3-5 hours; and in the electromagnetic induction heating process, the specific process conditions are that the heating temperature is 450-500 DEG C, the pressure is 80-150 MPa, and the holding time is 2-3 hours.

2. The method for preparing a lightweight and highly efficient heat-dissipating magnesium-based composite plate as described in claim 1, characterized in that... The preparation method comprises the following steps: S1. According to the shape and structure of the magnesium-based composite board to be prepared, a metal mold corresponding to the magnesium-based composite board is selected, and the size of the metal mold is 0.5-2.5 mm larger than that of the magnesium-based composite board; S2. The panel structure made of magnesium alloy material is selected as the substrate layer (1), and the panel structure made of pure copper material or copper alloy material is selected as the panel layer (2), and the heat-conducting material is prepared for standby; S3. One of the panel layers (2) is placed in the metal mold, then the heat-conducting material is uniformly placed on the panel layer (2), then the substrate layer (1) is placed on the heat-conducting material, then the heat-conducting material is uniformly placed on the substrate layer (1) in the same way, then the other panel layer (2) is placed on the heat-conducting material to form a green body, and finally the green body is subjected to a sealing treatment, wherein the sealing treatment is to seal the laminated green body in the metal mold; and a release agent is arranged in the metal mold in advance before the panel layer (2) is placed in the metal mold, the release agent is graphite, and the thickness of the release agent is 0.5-1.5 mm; S4. The encapsulated metal mold is preheated, and vacuumizing is performed during the heating process; the preheating temperature is 200-300°C, and the specific process conditions of the vacuumizing are: the degassing temperature is 200-300°C, the vacuum degree is 1X10 -1 -1X10 -3 Pa, and the degassing time is 5-15 hours; S5. The metal mold after the vacuumizing treatment is subjected to hot pressing in a hot pressing equipment, and the heat-conducting material is fused and formed into an integrated body with the substrate layer (1) and the panel layer (2) by hot pressing and curing to form an integrated composite laminated structure. The hot-pressing treatment is hot isostatic pressing treatment or electromagnetic induction heating treatment, wherein the hot isostatic pressing treatment is that the metal mold after vacuumizing is placed in a hot isostatic pressing machine to perform hot isostatic pressing treatment; and the electromagnetic induction heating treatment is that the metal mold after vacuumizing is placed in an electromagnetic induction heater to perform electromagnetic induction heating treatment. S6. The metal mold after the hot-pressing treatment is taken out from the hot-pressing equipment, cooled to room temperature, and disassembled to obtain a magnesium-based composite plate with a required shape and size.

3. The method of claim 2, wherein: The thickness of the substrate layer (1) is 15-25 mm, the thickness of the panel layer (2) is 1-5 mm, and the thickness of the transition layer (3) is 5-10 mm.

4. Use of the magnesium-based composite sheet according to claim 1 in electronic equipment, aerospace equipment, electric power equipment, or precision equipment, wherein The electronic equipment includes a mobile phone, a computer, a watch, a camera or a smart wearable device, is used for preparing a mobile phone frame, or a support skeleton of a computer, a watch, a camera or a smart wearable device; the aerospace equipment includes an aerospace structural part, is used for preparing an outer frame or a support skeleton of the aerospace structural part; the power equipment includes a measuring meter and a power supply device, is used for preparing an outer frame of the measuring meter, or a support skeleton of the power supply device; and the precision equipment includes a precision measuring or detecting instrument, is used for preparing an outer frame or a support skeleton of the precision measuring or detecting instrument.

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