Electronic device housing and manufacturing method therefor, and electronic device

Abstract

The present application relates to the technical field of materials, and in particular to an electronic device housing and a manufacturing method therefor, and an electronic device. The electronic device housing comprises a middle plate and a frame fixedly connected to the periphery of the middle plate, wherein the frame comprises a magnesium-based composite material, the magnesium-based composite material is doped with a powdered material reinforcement, the elastic modulus of the magnesium-based composite material is not less than 55 GPa, and the middle plate comprises a magnesium alloy having a thermal conductivity coefficient of not less than 90 W / m·k. The electronic device housing uses a high-modulus magnesium-based composite material as the frame and a highly thermally conductive magnesium alloy as the middle plate, the frame and the middle plate being fixedly connected to each other, and simultaneously has the properties of high strength, high modulus, and high thermal conductivity, etc., such that the overall structural stability of an electronic device can be enhanced, and the occurrence of an overheating phenomenon can be reduced, thereby reducing the risk of damage to internal components of the electronic device due to thermal stress, prolonging the service life of the electronic device, and facilitating the lightweight design of the electronic device.

Description

Electronic device frame and its preparation method, electronic device

[0001] This application claims priority to Chinese Patent Application No. 202411644700.4, filed on November 15, 2024, entitled "Electronic Device Frame and Preparation Method Thereof, Electronic Device", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of materials technology, and in particular to an electronic device frame and its preparation method, as well as an electronic device. Background Technology

[0003] With the continuous advancement and development of technology, electronic devices such as mobile phones and computers face numerous demands, including lighter weight, thinner walls, and higher strength. Producing high-quality products to meet market demands has become an urgent problem to solve in engineering. Traditional plastic products are increasingly unable to meet consumer needs, while metal electronic device frames offer advantages such as a smooth feel, wear resistance, drop resistance, and corrosion resistance, making them highly popular. Currently, aluminum alloy is the primary metal material used in manufacturing electronic device frames. The most common solution used by manufacturers in the mid-to-high-end market is a unibody design where the frame and middle plate are both made of the same aluminum alloy and CNC machined from a single aluminum sheet. However, in practice, aluminum alloy electronic device frames are difficult to reduce in weight. Furthermore, due to insufficient strength and modulus, and poor thermal conductivity, the frames deform significantly, potentially causing the screen glass to break. This also prevents the battery compartment area from being truly thinned. In addition, some manufacturers use stainless steel for the electronic device frame. Although stainless steel has sufficient strength and modulus, the PVD coating of stainless steel is easily scratched, and stainless steel has a high density, so it cannot bring weight reduction benefits to electronic products.

[0004] Therefore, it is particularly important to develop an electronic device frame with high strength and modulus, high thermal conductivity, and that facilitates device lightweighting. Summary of the Invention

[0005] The purpose of this application is to provide an electronic device frame and its manufacturing method, as well as an electronic device, which aims to solve the problems of insufficient strength and modulus and poor thermal conductivity of existing electronic device frames.

[0006] To achieve the above-mentioned objectives, the technical solution adopted in this application is as follows:

[0007] The first aspect of this application provides an electronic device frame, the electronic device frame including a middle plate and a frame fixedly connected around the middle plate; wherein, the frame is made of a magnesium-based composite material, the magnesium-based composite material being doped with powder material reinforcement, and the elastic modulus of the magnesium-based composite material being not less than 55 GPa; the middle plate is made of a magnesium alloy with a thermal conductivity of not less than 90 W / mk.

[0008] The electronic device frame provided in this application uses a high-modulus doped magnesium-based composite material as the frame and a magnesium alloy with high thermal conductivity as the middle plate. The magnesium alloy matrix itself has high plasticity and toughness, and also has advantages such as ease of fabrication, engineering reliability, and moderate price. On the one hand, the magnesium-based composite material in the frame is doped with powdered material reinforcement, which improves the elastic modulus and strength of the magnesium-based composite material. This results in an elastic modulus of the frame material of no less than 55 GPa, which is much higher than the elastic modulus of ordinary magnesium alloy (45 GPa) and close to or even exceeds the elastic modulus of aluminum alloy (68 GPa), achieving a drop performance equivalent to or even exceeding that of aluminum alloy. The high elastic modulus frame can maintain good shape stability under external force and is not prone to deformation, thereby enhancing the overall structural stability of the electronic device and its frame, making it less prone to deformation and damage. It also improves the impact resistance of the electronic device. When subjected to impact, the high elastic modulus material can better absorb and disperse the impact force, reducing the risk of damage to internal components and extending the service life of the electronic device. Furthermore, the high elastic modulus frame typically possesses good rigidity and toughness, making the frame of the electronic device more stable to hold and less prone to slipping, thus improving the user experience. On the other hand, the middle plate uses a magnesium alloy with a thermal conductivity of not less than 90W / mk, which is equal to or even exceeds that of ordinary 7-series aluminum alloys. The high thermal conductivity of the middle plate can more quickly conduct heat generated inside the electronic device, thereby effectively reducing the operating temperature of the electronic device and reducing the occurrence of overheating. Through efficient heat dissipation, it can be ensured that key components such as the processor and battery of the electronic device can maintain stable performance output in high-temperature environments, reducing thermal stress caused by temperature changes, avoiding performance degradation or failure due to overheating, reducing the risk of damage to internal components caused by thermal stress, extending the service life of internal components, and improving the overall durability of the electronic device. In this application, the middle plate and the frame are fixedly connected, forming a connection area between the frame and the middle plate of a high-modulus magnesium-based composite material and a high thermal conductivity magnesium alloy material, resulting in an electronic device frame with high strength, high modulus, and high thermal conductivity, which can better meet the application requirements of electronic devices. Furthermore, compared to stainless steel and aluminum alloy electronic device frames, the weight of the frame is reduced, which helps to reduce the thickness of areas such as the battery compartment in electronic devices, contributing more battery capacity and facilitating lightweight design of electronic devices.

[0009] As some possible implementations of the electronic device frame of this application, the mass percentage of the powder material reinforcement doped in the magnesium-based composite material is 5% to 30%; this content can sufficiently ensure the improvement of the elastic modulus and strength of the magnesium-based composite material without affecting the matrix properties of the magnesium alloy material.

[0010] As some possible implementations of the electronic device frame of this application, the powder material reinforcement includes at least one of SiC, TiB2, Al2O3, graphite, and graphene; these materials can all improve the elastic modulus of magnesium-based composite materials.

[0011] As some possible implementations of the electronic device frame of this application, the particle size D50 of the powder material reinforcement is greater than 0 and not higher than 20 μm. The small particle size and high uniformity of the powder material reinforcement, when evenly distributed in the magnesium-based composite material, can better enhance the strength and elastic modulus of the magnesium-based composite material.

[0012] As some possible implementations of the electronic device frame of this application, the magnesium-based composite material contains the following components in mass percentage: Al content of 9.5% to 10.5%, Zn content of 0.91% to 1.35%, Mn content of 0.41% to 0.9%, Si content ≤0.1%, total impurity element content <0.1%, and the balance being Mg.

[0013] As some possible implementations of the electronic device frame of this application, the magnesium-based composite material includes at least one of AZ31B magnesium alloy and AZ91D magnesium alloy as the magnesium alloy substrate. These magnesium-based composite materials have good mechanical properties, high vibration resistance and thermal conductivity, as well as good corrosion resistance and electrical conductivity.

[0014] As some possible implementations of the electronic device frame of this application, the middle plate includes at least one magnesium alloy with a Zn content of ≥5%. These magnesium alloys all have extremely high thermal conductivity.

[0015] As some possible implementations of the electronic device frame of this application, the magnesium alloy in the middle plate contains the following components by mass percentage: Zn content of 7% to 9%, Zr content of 1% to 3%, rare earth element content of 0.1% to 0.5%, Al content of 0.1% to 0.7%, Ti element content of 0.05% to 0.3%, total impurity element content of <0.5%, and the balance being Mg.

[0016] As some possible implementations of the electronic device frame of this application, the middle plate comprises ZK60 magnesium alloy.

[0017] As some possible implementations of the electronic device frame of this application, the rare earth element includes at least one of lanthanum, cerium, yttrium, and scandium.

[0018] As some possible implementations of the electronic device frame of this application, the elastic modulus of the magnesium-based composite material is 60GPa to 80GPa. In this case, the elastic modulus of the magnesium-based composite material is much higher than that of ordinary magnesium alloy (45GPa) and close to or even exceeds that of aluminum alloy (68GPa). This achieves a drop effect equivalent to or even exceeding that of aluminum alloy, thus better protecting the electronic device and extending its service life.

[0019] As some possible implementations of the electronic device frame in this application, the magnesium alloy in the middle plate has a thermal conductivity of 110 W / mK to 160 W / mK. In this case, the magnesium alloy used in the middle plate has a high thermal conductivity, equal to or even exceeding that of ordinary 7-series aluminum alloys, which can more quickly conduct away the heat generated inside the electronic device, thereby effectively reducing the operating temperature of the electronic device and reducing the occurrence of overheating. This reduces the risk of damage to internal components of the electronic device due to thermal stress, extends the service life of internal components, and improves the overall durability of the electronic device.

[0020] As some possible implementations of the electronic device frame in this application, the electronic device frame includes at least one of a mobile phone frame, a tablet computer frame, and a smartwatch frame.

[0021] Secondly, this application provides a method for manufacturing an electronic device frame, comprising the following steps:

[0022] A magnesium-based composite material doped with powder material reinforcement is obtained and used to make a frame; the elastic modulus of the magnesium-based composite material is not less than 55 GPa;

[0023] A magnesium alloy with a thermal conductivity of not less than 90 W / mk is used to make a medium plate;

[0024] The frame is fixedly connected to the perimeter of the middle plate and processed to form the electronic device frame.

[0025] This application describes a method for manufacturing an electronic device frame. A frame is made of a magnesium-based composite material doped with powdered material reinforcement and having an elastic modulus of not less than 55 GPa. A middle plate is made of a magnesium alloy with a thermal conductivity of not less than 90 W / mK. The frame is then fixedly connected to the perimeter of the middle plate, and the frame is processed to obtain the electronic device frame. The manufacturing process is simple and suitable for large-scale industrial production and application. The magnesium-based composite material in the frame is doped with powdered material reinforcement, ensuring that the frame material has an elastic modulus of not less than 55 GPa, achieving drop resistance equivalent to or even exceeding that of aluminum alloy. The high elastic modulus of the frame makes it less prone to deformation under external force, thereby enhancing the overall structural stability of the electronic device and its frame, reducing deformation and damage, and extending the service life of the electronic device. The middle plate, made of magnesium alloy with a thermal conductivity of not less than 90 W / mK, can more quickly conduct heat generated inside the electronic device, effectively reducing the operating temperature of the electronic device, reducing the occurrence of overheating, lowering the risk of damage to internal components due to thermal stress, extending the service life of internal components, and improving the overall durability of the electronic device. By combining a high-strength and high-modulus frame with a high-thermal-conductivity middle plate, the electronic device frame simultaneously possesses characteristics such as high strength, high modulus, and high thermal conductivity, which can better meet the application requirements of electronic devices and is also conducive to the lightweight design of electronic devices.

[0026] As some possible implementations of the method for manufacturing the electronic device frame of this application, the method of using the magnesium-based composite material to prepare the frame includes at least one of: stir casting, squeeze casting, semi-solid die casting, and hot chamber die casting. These processes can all produce a frame of a specific shape from the magnesium-based composite material.

[0027] As some possible implementations of the method for manufacturing the electronic device frame of this application, the method of using the magnesium alloy to prepare the middle plate includes at least one of: stir casting, squeeze casting, semi-solid die casting, and hot chamber die casting. These processes can all produce a middle plate of a specific shape from the magnesium alloy.

[0028] As some possible implementations of the method for manufacturing the electronic device frame of this application, the method of fixing the frame to the periphery of the middle plate includes friction stir welding. In this case, the microstructure of the heat-affected zone of the weld joint changes little, the residual stress is relatively low, and the welded workpiece is not easily deformed; the operation process is convenient to achieve mechanization and automation, the equipment is simple, energy consumption is low, efficiency is high, the requirements for the working environment are low, and the welding process is safe, pollution-free, smoke-free, and radiation-free.

[0029] As some possible implementations of the method for manufacturing the electronic device frame of this application, the processing method includes CNC machine tool processing. According to a pre-programmed processing program, the CNC device and servo system control the machine tool spindle and feed actuators to realize the relative movement or position change between the tool and the workpiece, thereby completing the processing of the electronic device frame and obtaining a high-precision electronic device frame with a complex three-dimensional structure.

[0030] As some possible implementations of the method for preparing the electronic device frame of this application, the width of the stirring zone in the friction stir welding is 3mm to 10mm; the width of this part of the zone is the diameter of the stirring head of the friction stir welding, and this width range can meet the preparation requirements of different types of electronic device frames.

[0031] As some possible implementations of the method for preparing the electronic device frame of this application, in the welding area between the frame and the middle plate, the concentration of the magnesium-based composite material increases along the direction from the middle plate to the frame, and the concentration of the magnesium alloy decreases along the direction from the middle plate to the frame.

[0032] Thirdly, this application provides an electronic device comprising the above-described electronic device frame or an electronic device frame prepared by the above-described preparation method.

[0033] The electronic device of this application includes the aforementioned electronic device frame, which is made of high-modulus magnesium-based composite material as the frame and high thermal conductivity magnesium alloy as the middle plate. The two are fixedly connected and have high strength, high modulus, and high thermal conductivity. This not only enhances the overall structural stability of the electronic device, but also reduces the occurrence of overheating, reduces the risk of damage to internal components due to thermal stress, extends the service life of the electronic device, and is also conducive to the lightweight design of the electronic device.

[0034] As some possible implementations of the electronic device frame in this application, the electronic device includes mobile terminal devices, such as mobile phones, tablets, in-vehicle computers, and smartwatches.

[0035] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0036] Figure 1 is a schematic diagram of an electronic device provided in an embodiment of this application;

[0037] Figure 2 is a schematic diagram of a mobile phone mid-frame provided in an embodiment of this application;

[0038] Figure 3 is a schematic flowchart of the method for manufacturing an electronic device provided in an embodiment of this application. Detailed Implementation

[0039] To make the technical problems, technical solutions, and beneficial effects of this application clearer, the following detailed description is provided in conjunction with embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0040] In this application, the term "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0041] In this application, "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, "at least one of a, b, or c", or "at least one of a, b, and c", can both mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0042] It should be understood that in the various embodiments of this application, the order of the above processes does not imply the order of execution. Some or all steps may be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0043] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms “a,” “the,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0044] The term "MMC" is an abbreviation for "Metal Matrix Composite," referring to composite materials made from metals or alloys as the matrix and reinforced with fibers, whiskers, particles, etc. Main types include metal matrix composites reinforced with high-performance reinforcing fibers, whiskers, and particles; reaction-reinforced composites within a metal matrix; and laminated metal matrix composites. These metal matrix composites retain the properties of the metal itself while also possessing the comprehensive characteristics of composite materials. Through optimized combinations of different matrices and reinforcements, various high-performance composite materials with diverse special properties and excellent overall performance can be obtained. Metal matrix composites can be classified according to the type of matrix material, including aluminum-based, magnesium-based, zinc-based, copper-based, and intermetallic compound-based composites.

[0045] The term "Mg MMC" is an abbreviation for "Magnesium metal matrix composite," referring to a type of metal matrix composite material whose matrix material is magnesium or magnesium alloys, containing ceramic or fiber reinforcements. The inherent plasticity and toughness of magnesium alloy matrices, along with their ease of machining, engineering reliability, and moderate price, make them ideal for engineering applications.

[0046] The term "CNC" is an abbreviation for "Computer Numerical Control," referring to CNC machine tool machining, a process method for machining parts on CNC machine tools. A CNC machine tool is a machine tool controlled by a computer; its movements and auxiliary actions are controlled by instructions issued by the CNC system. The basic principle of CNC machine tool machining is to control the machine tool spindle and feed mechanisms, etc., according to a pre-programmed machining program, through CNC devices and servo systems, to achieve the relative movement or positional change between the tool and the workpiece, thereby completing the machining of the workpiece.

[0047] The term "FSW" is an abbreviation for "Friction Stir Welding," a purely mechanical, continuous solid-state joining method that utilizes the frictional heat generated by a rotating tool to join materials. The working principle involves a cylindrical stirring head with special shoulders and pin protrusions, which is slowly inserted into the workpiece to be welded. The frictional shear resistance between the stirring head and the workpiece generates frictional heat, causing the material in the vicinity of the stirring head to thermoplasticize (the welding temperature generally does not reach or exceed the melting point of the workpiece). As the stirring head rotates forward, the thermoplasticized metal material transfers from the leading edge to the trailing edge, and under the combined action of frictional heat generated between the stirring head and the workpiece surface, and the forging action, a dense solid-state joint is formed.

[0048] The term "PVD" is an abbreviation for "Physical Vapor Deposition," which is a process that deposits materials onto the surface of a workpiece to form a thin film through physical processes in a vacuum environment.

[0049] The term "elastic modulus" refers to the ratio of stress to normal strain in a material during the elastic deformation stage; it is also known as Young's modulus.

[0050] The term "thermal conductivity" refers to the amount of heat transferred through a 1-meter-thick material with a temperature difference of 1 degree Celsius (K, °C) between its two surfaces over a certain period of time under steady-state heat transfer conditions. The unit is watts per meter per degree Celsius (W / (m·K), where K can be replaced by °C). Thermal conductivity is a physical quantity that represents a material's ability to conduct heat; it reflects the amount of heat passing through a unit area per unit thickness, unit temperature difference, and unit time under steady-state heat transfer conditions.

[0051] Currently, from a market perspective, metal electronic device frames are highly favored by consumers due to their advantages such as a smooth feel, wear resistance, drop resistance, and corrosion resistance. Currently, aluminum alloy is the primary metal material used in the manufacture of frames for electronic devices such as mobile phones, computers, and smartwatches. Among current electronic device frame manufacturers, the most common solution in mid-to-high-end applications is to machine the frame and middle plate as a single piece, using the same aluminum alloy and CNC machining from the same aluminum sheet. However, the current aluminum alloy modulus is only 68GPa to 72GPa. During application, insufficient strength and modulus in the electronic device frame result in poor thermal conductivity, leading to significant deformation and potentially causing the screen glass to break. Furthermore, the insufficient strength and modulus of aluminum alloy electronic device frames prevent the battery compartment area from being truly thinned, hindering the contribution of more battery capacity and weight reduction. Therefore, it is difficult to achieve weight reduction with aluminum alloy electronic device frames in practical applications.

[0052] To address the issues of insufficient strength and modulus, as well as low thermal conductivity, in electronic device frames, research has found that some manufacturers use stainless steel for their frames. While stainless steel offers sufficient strength and modulus, its PVD coating is easily scratched, and stainless steel has a high density (7.70 g / cm³). 3 ~8.00g / cm 3 (Aluminum alloy 2.63g / cm) 3 ~2.85g / cm 3 This cannot bring weight reduction benefits to electronic products.

[0053] Based on this, some embodiments of this application propose using different materials for the frame and middle plate of the electronic device chassis. For example, the frame uses a titanium-aluminum alloy composite material, and the middle plate uses aluminum alloy, with the frame and middle plate welded together by laser welding. Although the elastic modulus of titanium alloy is around 110 GPa, titanium and aluminum are two completely different materials. Processing them into a layered composite material easily leads to deformation, affecting the dimensional yield of the electronic device chassis. Furthermore, the bonding between titanium and aluminum is largely mechanical, and their interface is prone to brittle phases, significantly impacting the reliability of the battery compartment area. Using aluminum alloy for the battery compartment in the middle plate has a modulus of only 68 GPa to 72 GPa, limiting the potential for weight reduction and thinning. Additionally, laser welding requires melting part of the aluminum alloy, resulting in a large heat input and inevitably generating thermal stress, further affecting the dimensional yield of the electronic device chassis.

[0054] Some other embodiments of this application propose using a titanium-aluminum layered composite material for the frame of the electronic device, and an aluminum alloy for the middle plate, with the frame and middle plate joined by friction stir welding (FSW). This approach also has drawbacks: titanium and aluminum are two completely different materials, and processing them into a layered composite material easily leads to deformation, affecting the dimensional yield of the middle frame. Furthermore, the bonding between titanium and aluminum is largely mechanical, and their interface is prone to forming brittle phases, significantly impacting the reliability of the battery compartment area. The middle plate battery compartment is made of aluminum alloy, but aluminum alloy modulus is only 68 GPa to 72 GPa, limiting the potential for weight reduction and thinning. Additionally, FSW welding requires frictional heat generated by high-speed stirring to partially melt the material, inevitably generating thermal stress and affecting the dimensional yield of the middle frame.

[0055] Some other embodiments of this application propose using aluminum alloy for the frame of the electronic device housing, and aluminum-based composite material, 7-series aluminum alloy, die-cast aluminum alloy, magnesium-based composite material, high-strength magnesium alloy, or die-cast magnesium alloy for the middle plate, etc., with the frame and middle plate joined by FSW friction stir welding. In this scheme, the bonding between aluminum alloy and non-aluminum-based materials is largely mechanical, which significantly reduces the reliability of the battery compartment area. Furthermore, FSW welding requires the frictional heat generated by high-speed stirring to partially melt the material, inevitably producing thermal stress and affecting the yield of the middle frame dimensions.

[0056] Some other embodiments of this application propose using a magnesium alloy to make a one-piece electronic device frame. In this solution, the magnesium alloy frame has insufficient elastic modulus compared to the aluminum alloy frame, and the overall three-point bending stiffness is significantly reduced by about 39%, which does not meet the overall reliability requirements of the device.

[0057] In this application embodiment, the electronic device frame refers to the structure located between the front panel and the back cover of an electronic device, which supports various internal components such as batteries, motherboards, cameras, ribbon cables, various sensors, microphones, and earpieces. It serves as the "skeleton" for fixing and installing these components. Simultaneously, the electronic device frame also protects the internal components from external impacts and damage. For example, the electronic device includes mobile terminal devices such as mobile phones, tablets, laptops, and smartwatches.

[0058] Based on the above considerations, and to address the issues of insufficient strength and modulus, as well as poor thermal conductivity, in electronic device frames, this application proposes an electronic device frame that uses a high-modulus magnesium-based composite material as the frame and a high-thermal-conductivity magnesium alloy as the middle plate, with the two fixedly connected. This results in an electronic device frame that simultaneously possesses high strength, high modulus, and high thermal conductivity, better meeting the application requirements of electronic devices. Furthermore, compared to aluminum alloy electronic device frames, it reduces the frame's weight, which is beneficial for reducing the thickness of the battery compartment area, contributing more battery capacity, and facilitating lightweight design of electronic devices.

[0059] For ease of understanding, this application is specifically described through the following embodiments. It should be understood that the following embodiments are only used to illustrate the solution of this application and are not intended to limit the scope of this application.

[0060] As shown in Figure 1, this application embodiment provides an electronic device frame, which includes a middle plate and a frame fixedly connected around the middle plate; wherein, the frame is made of magnesium-based composite material, the magnesium-based composite material is doped with powder material reinforcement, and the elastic modulus of the magnesium-based composite material is not less than 55 GPa; the middle plate is made of magnesium alloy with a thermal conductivity of not less than 90 W / mk.

[0061] Thus, the electronic device frame provided in this application uses a high-modulus doped magnesium-based composite material as the frame and a magnesium alloy with high thermal conductivity as the middle plate. The magnesium alloy matrix itself has high plasticity and toughness, and also has advantages such as ease of fabrication, engineering reliability, and moderate price. On the one hand, the magnesium-based composite material in the frame is doped with powdered material reinforcement, which improves the elastic modulus and strength of the magnesium-based composite material, making the elastic modulus of the frame material no less than 55 GPa, far higher than the elastic modulus of ordinary magnesium alloy (45 GPa), and close to or even exceeding the elastic modulus of aluminum alloy (68 GPa), achieving a drop effect equivalent to or even exceeding that of aluminum alloy. The high elastic modulus frame can maintain good shape stability when subjected to external forces, and is not prone to deformation, thereby enhancing the overall structural stability of the electronic device and its frame, making it less prone to deformation and damage. It improves the impact resistance of the electronic device. When subjected to impact, the high elastic modulus material can better absorb and disperse the impact force, reducing the risk of damage to the internal components of the electronic device and extending the service life of the electronic device. Furthermore, the high elastic modulus frame typically possesses good rigidity and toughness, making the frame of the electronic device more stable to hold and less prone to slipping, thus improving the user experience. On the other hand, the middle plate uses a magnesium alloy with a thermal conductivity of not less than 90W / mk, which is equal to or even exceeds that of ordinary 7-series aluminum alloys. The high thermal conductivity of the middle plate can more quickly conduct heat generated inside the electronic device, thereby effectively reducing the operating temperature of the electronic device and reducing the occurrence of overheating. Through efficient heat dissipation, it can be ensured that key components such as the processor and battery of the electronic device can maintain stable performance output in high-temperature environments, reducing thermal stress caused by temperature changes, avoiding performance degradation or failure due to overheating, reducing the risk of damage to internal components caused by thermal stress, extending the service life of internal components of the electronic device, and improving the overall durability of the electronic device. In the embodiment of this application, the plate and the frame are fixedly connected, forming a connection area between the frame and the middle plate of a high-modulus magnesium-based composite material and a high thermal conductivity magnesium alloy material, resulting in an electronic device frame with high strength, high modulus, and high thermal conductivity, which can better meet the application requirements of electronic devices. Furthermore, compared to stainless steel and aluminum alloy electronic device frames, the weight of the frame is reduced, which helps to reduce the thickness of areas such as the battery compartment in electronic devices, contributing more battery capacity and facilitating lightweight design of electronic devices.

[0062] In this embodiment of the electronic device frame, the frame is fixedly connected to the perimeter of the middle plate. The frame of the electronic device frame refers to the border portion of the electronic device frame, also often referred to as the perimeter frame or skeleton of the electronic device frame. It is part of the external structure of the electronic device, located on the outermost layer, and usually forms the overall appearance of the electronic device together with components such as the display screen and back cover. The frame is close to the edge of the display screen, and sometimes extends to the sides and top / bottom edges of the electronic device. The primary function of the frame is to protect the display screen from impacts and scratches. When the electronic device is dropped or subjected to external impact, the frame can absorb some of the impact force, reducing the risk of damage to the display screen. The frame also serves to fix internal components such as cameras, speakers, and buttons, ensuring they are securely mounted on the electronic device. The design of the frame also directly affects the aesthetics of the electronic device and the user's tactile experience; different materials, colors, and shapes of frames can give the electronic device different styles and textures. The middle plate of the electronic device frame refers to a key component in the internal structure of the electronic device, also called the middle frame or middle frame plate. The mid-frame, typically installed within the main frame of electronic devices, supports various internal components such as batteries, motherboards, and camera modules. It serves to support and protect these components, ensuring their proper functioning and coordination. During use, the mid-frame effectively absorbs and disperses external impacts, preventing damage to internal components. It also aids in heat dissipation, preventing overheating under heavy use. The design and material selection of the mid-frame directly affect the overall structural strength of the electronic device. High-quality mid-frame materials significantly improve the device's drop resistance and durability.

[0063] For example, the elastic modulus of the magnesium-based composite material in the frame can be any typical but non-limiting point value or a range between any two point values, such as 55 GPa, 60 GPa, 65 GPa, 70 GPa, 75 GPa, 80 GPa, 90 GPa, 100 GPa, 110 GPa; the thermal conductivity of the magnesium alloy in the middle plate can be any typical but non-limiting point value or a range between any two point values, such as 90 W / mk, 95 W / mk, 100 W / mk, 105 W / mk, 110 W / mk, 120 W / mk, 130 W / mk, 140 W / mk, 150 W / mk, 160 W / mk, 180 W / mk, 190 W / mk, 200 W / mk.

[0064] In some possible implementations, the electronic device frame includes at least one of a mobile phone frame, a tablet frame, and a smartwatch frame. The mobile phone frame is a crucial component of the phone, located between the front panel and back cover. It supports various internal components such as the battery, motherboard, camera, ribbon cables, various sensors, microphone, and earpiece, serving as the "skeleton" for fixing and mounting these components. Simultaneously, the mobile phone frame also protects the internal components from external impacts and damage. Similarly, the tablet and smartwatch frames are also located between the front panel and back cover, forming the main skeletal framework that supports the various internal components of the electronic device.

[0065] In some embodiments, the electronic device frame is a mobile phone mid-frame. A schematic diagram of one structure of the mobile phone mid-frame is shown in Figure 2, wherein the border is the four edges of the mid-frame, and the mid-plate includes a battery compartment area, a non-battery compartment area, etc.

[0066] In some possible implementations, the mass percentage of powdered material reinforcement doped in the magnesium matrix composite is 5% to 30%. In this case, the content of powdered material reinforcement doped in the magnesium matrix composite sufficiently ensures an improvement in the elastic modulus and strength of the magnesium matrix composite without affecting the matrix properties of the magnesium alloy. This results in an elastic modulus of the magnesium matrix composite of not less than 55 GPa, achieving a drop resistance performance of the electronic device frame equivalent to or even exceeding that of aluminum alloys, thereby improving the service life of the electronic device. For example, the mass percentage of powdered material reinforcement doped in the magnesium matrix composite can be any typical but non-limiting value, such as 5%, 10%, 15%, 20%, 25%, or 30%, or a range between any two values.

[0067] In some possible implementations, the powder material reinforcement includes at least one of SiC, TiB2, Al2O3, graphite, and graphene. In this case, the ceramic particles, ceramic fibers, carbon fibers, and other materials doped in the magnesium-based composite material have characteristics such as low density, mechanical compatibility, chemical compatibility, thermal stability, high elastic modulus, high compressive or tensile strength, good processability, and low cost, all of which can improve the elastic modulus of the composite material.

[0068] In some possible implementations, the particle size D50 of the powder reinforcement is greater than 0 and not higher than 20 μm. In this case, the small particle size and high uniformity of the powder reinforcement, when evenly distributed in the magnesium matrix composite, can better enhance the strength and elastic modulus of the magnesium matrix composite. Smaller particles can be more effectively dispersed in the magnesium alloy matrix, forming a more uniform reinforcing phase distribution, thereby improving the overall stiffness of the alloy. The reduction in particle size also helps to improve the strength of the alloy. Smaller particles can more effectively hinder dislocation movement and crack propagation, reduce the possibility of stress concentration, and improve the fracture toughness of the material, thereby improving the yield strength and tensile strength of the material. Furthermore, the small-particle-size powder reinforcement has less impact on the elongation and other properties of the magnesium alloy matrix. For example, the particle size D50 of the powder material reinforcement can be any typical but non-limiting point value or an interval value between any two point values, such as 0.1μm, 0.5μm, 1μm, 1.5μm, 2μm, 2.5μm, 3μm, 4μm, 5μm, 6μm, 7μm, 8μm, 9μm, 10μm, 11μm, 12μm, 13μm, 14μm, 15μm, 16μm, 17μm, 18μm, 19μm, 20μm.

[0069] In some possible embodiments, the magnesium-based composite material contains the following components by mass percentage: Al content 9.5%–10.5%, Zn content 0.91%–1.35%, Mn content 0.41%–0.9%, Si content ≤0.1%, total impurity element content <0.1%, and the balance being Mg. In this formulation, Mg, as the main element, provides the basic structure and strength of the alloy. By strictly controlling the content of Si and other impurity elements, the corrosion tendency of the magnesium alloy can be reduced, helping to avoid the formation of silicides, thereby reducing internal defects and surface inhomogeneities and improving corrosion resistance. Appropriate amounts of Mn can improve the toughness of the magnesium alloy and enhance its shock resistance. Appropriate amounts of Al, Zn, Mn, and other elements can enhance the strength and hardness of the alloy, giving the magnesium alloy substrate high modulus and high strength, which can significantly improve the drop resistance and three-point bending performance of electronic device frames.

[0070] In some possible embodiments, the magnesium alloy substrate in the magnesium-based composite material includes at least one of AZ31B magnesium alloy and AZ91D magnesium alloy. AZ31B magnesium alloy is a wrought magnesium alloy; "AZ" indicates that the alloy is formed from magnesium and aluminum, "31" indicates its alloy number, and "B" indicates the alloy grade. Its main components include elements such as magnesium (Mg), aluminum (Al), silicon (Si), zinc (Zn), manganese (Mn), iron (Fe), copper (Cu), and nickel (Ni), with specific component proportions as follows: Mg: balance, Al: 2.5%–3.5%, Si: ≤0.08%, Ca: ≤0.04%, Zn: 0.6%–1.4%, Mn: 0.2%–1.0%, Fe: ≤0.003%, Cu: ≤0.01%, Ni: ≤0.001%. AZ31B magnesium alloy has a tensile strength of 245MPa–290MPa, a grain size of 8μm–15μm, and an elongation at break of 3%–10%. It possesses good mechanical properties, high vibration resistance and heat absorption capacity, as well as good corrosion resistance and electrical conductivity. AZ91D magnesium alloy mainly consists of magnesium (Mg), aluminum (Al), zinc (Zn), and small amounts of manganese (Mn), silicon (Si), copper (Cu), nickel (Ni), and iron (Fe). The specific composition ratio is: Mg balance, Al 8.5%–9.5%, Zn 0.45%–0.90%, and other elements in low amounts. The density of AZ91D magnesium alloy is approximately 1.82 g / cm³. 3 The temperature is relatively low, which is beneficial for lightweight design. The Brinell hardness is ≥63HB, indicating high hardness. The thermal conductivity is approximately 72W / Mk, providing good thermal conductivity. The tensile strength is approximately 250MPa, the yield point is approximately 160MPa, the elongation is approximately 7%, and the Young's modulus is approximately 44.8GPa.

[0071] In some possible implementations, the elastic modulus of the magnesium-based composite material is between 60 GPa and 80 GPa. In this case, the elastic modulus of the magnesium-based composite material is much higher than that of ordinary magnesium alloys (45 GPa) and approaches or even exceeds that of aluminum alloys (68 GPa). This achieves drop protection equivalent to or even better than that of aluminum alloys, thus better protecting electronic devices, extending their lifespan, and improving the user experience. For example, the elastic modulus of the magnesium-based composite material can be any typical but non-limiting point value such as 60 GPa, 65 GPa, 70 GPa, 75 GPa, or 80 GPa, or a range between any two point values.

[0072] In some possible implementations, the medium plate comprises at least one magnesium alloy with a Zn content ≥ 5%. In this case, the magnesium alloy with a Zn content ≥ 5% typically exhibits significantly improved strength, as high Zn content magnesium alloys tend to possess higher tensile and yield strengths, enabling them to withstand greater loads and stresses. Furthermore, the addition of Zn can form a dense oxide protective film, thus improving the corrosion resistance of the magnesium alloy. The addition of Zn can also improve the fluidity of the magnesium alloy, making it easier to fill the mold during casting, reducing casting defects, and resulting in better casting performance and a higher casting yield.

[0073] In some possible implementations, the magnesium alloy in the medium plate contains the following components by mass percentage: 7%–9% Zn, 1%–3% Zr, 0.1%–0.5% rare earth elements, 0.1%–0.7% Al, 0.05%–0.3% Ti, <0.5% total impurity elements, and the balance being Mg. In this case, the high zinc content in the magnesium alloy in the medium plate ensures a thermal conductivity above 90 W / mK. The addition of elements such as Zn and Zr improves the alloy's casting properties and enhances the quality of the castings. Zr has a grain-refining effect in magnesium alloys, primarily due to two factors: firstly, Zr can act as heterogeneous nuclei for Mg growth, increasing the nucleation rate and refining the grains; secondly, Zr reduces the diffusion rate, inhibiting grain growth and further refining the grains; this is beneficial for strength improvement.

[0074] In some possible implementations, rare earth elements include at least one of lanthanum (La), cerium (Ce), yttrium (Y), and scandium (Sc). These rare earth metals in magnesium alloys are beneficial for refining grain size and increasing the strength of the magnesium alloy.

[0075] In some possible implementations, the middle plate comprises ZK60 magnesium alloy, which has extremely high thermal conductivity. The main chemical components of ZK60 magnesium alloy include magnesium (Mg), zinc (Zn), zirconium (Zr), and other trace elements such as copper (Cu), silicon (Si), iron (Fe), manganese (Mn), chromium (Cr), and titanium (Ti). The magnesium content is typically above 95%, the zinc content is around 6%, and the zirconium content is around 0.5%. This alloy has a fine grain size and high grain boundary density, giving it excellent strength and toughness. The density of ZK60 magnesium alloy is approximately 2.72 g / cm³. 3 It has relatively low tensile strength, which is beneficial for lightweight design; it has high tensile strength and yield strength, which can withstand large forces and loads; it has high hardness; and under certain conditions, it has a certain elongation, which ensures the toughness of the material.

[0076] In some possible implementations, the magnesium alloy in the middle plate has a thermal conductivity of 110 W / mK to 160 W / mK. In this case, the magnesium alloy used in the middle plate has a high thermal conductivity, equal to or even exceeding that of ordinary 7-series aluminum alloys. The high thermal conductivity of the middle plate allows for more rapid heat dissipation from the inside of the electronic device, effectively reducing its operating temperature and minimizing overheating. This avoids performance degradation or malfunctions caused by overheating, reduces the risk of damage to internal components due to thermal stress, extends the lifespan of internal components, and improves the overall durability of the electronic device. For example, the thermal conductivity of the magnesium alloy in the medium plate can be any typical but non-limiting point value or an interval between any two point values, such as 110W / mk, 113W / mk, 115W / mk, 118W / mk, 120W / mk, 123W / mk, 125W / mk, 128W / mk, 130W / mk, 135W / mk, 140W / mk, 145W / mk, 150W / mk, 155W / mk, 160W / mk.

[0077] The electronic device frame of the above embodiments of this application can be obtained by the following methods.

[0078] This application provides a method for manufacturing an electronic device frame, as shown in Figure 3, including the following steps:

[0079] S10. Obtain a magnesium-based composite material doped with powder material reinforcement and use it to make a frame; the elastic modulus of the magnesium-based composite material is not less than 55 GPa;

[0080] S20. Obtain a magnesium alloy with a thermal conductivity of not less than 90 W / mk and make it into a medium plate;

[0081] S30. Fix the frame to the four sides of the middle plate, process it, and form the electronic device frame.

[0082] This application describes a method for manufacturing an electronic device frame. A frame is made of a magnesium-based composite material with a modulus of elasticity not less than 55 GPa and doped with powdered material reinforcement. A middle plate is made of a magnesium alloy with a thermal conductivity not less than 90 W / mK. The frame is then fixedly connected to the perimeter of the middle plate, and the electronic device frame is obtained through processing. The manufacturing process is simple and suitable for large-scale industrial production and application. The magnesium-based composite material in the frame is doped with powdered material reinforcement, ensuring that the frame material has a modulus of elasticity not less than 55 GPa, achieving a drop resistance equivalent to or even exceeding that of aluminum alloy. The high modulus of elasticity of the frame makes it less prone to deformation under external force, thereby enhancing the overall structural stability of the electronic device and its frame, reducing deformation and damage, and extending the service life of the electronic device. The middle plate, made of a magnesium alloy with a thermal conductivity not less than 90 W / mK, can more quickly conduct heat generated inside the electronic device, effectively reducing the operating temperature of the electronic device, reducing the occurrence of overheating, lowering the risk of damage to internal components due to thermal stress, extending the service life of internal components, and improving the overall durability of the electronic device. By combining a high-strength and high-modulus frame with a high-thermal-conductivity middle plate, the electronic device frame simultaneously possesses characteristics such as high strength, high modulus, and high thermal conductivity, which can better meet the application requirements of electronic devices and is also conducive to the lightweight design of electronic devices.

[0083] In step S10 above:

[0084] In some possible implementations, the methods for preparing frames using magnesium-based composite materials include at least one of the following: stir casting, squeeze casting, semi-solid die casting, and hot chamber die casting. These processes can all produce frames of specific shapes from magnesium-based composite materials. Stir casting involves mechanically stirring to evenly disperse reinforcing particles added to molten liquid metal, then casting the mixture into a mold to obtain the desired billet and part. Squeeze casting, also known as liquid forging, is a combined casting and forging process where liquid metal is formed under high pressure with slight plastic deformation, effectively reducing shrinkage defects in castings, improving the density of the workpiece's microstructure, and significantly enhancing mechanical properties through heat treatment. Semi-solid die casting utilizes the fluidity and plasticity of magnesium alloys in a semi-solid state to form the shape. Hot chamber die casting refers to a casting process where the pressure chamber is immersed in liquid metal in a heat-preserving molten crucible, and the injection component is not directly connected to the machine base but rather mounted on top of the crucible.

[0085] In some possible implementations, the mass percentage of the powder material reinforcement doped in the magnesium-based composite material is 5% to 30%.

[0086] In some possible implementations, the powder material reinforcement includes at least one of SiC, TiB2, Al2O3, graphite, and graphene.

[0087] In some possible implementations, the particle size D50 of the powder material reinforcement is greater than 0 and not higher than 20 μm.

[0088] In some possible embodiments, the magnesium-based composite material contains the following components in mass percentage: Al content of 9.5% to 10.5%, Zn content of 0.91% to 1.35%, Mn content of 0.41% to 0.9%, Si content ≤0.1%, total impurity element content <0.1%, and the balance being Mg.

[0089] In some possible implementations, the magnesium alloy substrate in the magnesium-based composite material includes at least one of AZ31B magnesium alloy and AZ91D magnesium alloy.

[0090] In some possible implementations, the elastic modulus of the magnesium-based composite material is 60 GPa to 80 GPa.

[0091] The beneficial effects of the magnesium-based composite material features in the above embodiments of this application have been discussed in the foregoing and will not be repeated here.

[0092] In step S20 above:

[0093] In some possible implementations, the methods for preparing medium plates using magnesium alloys include at least one of the following: stir casting, squeeze casting, semi-solid die casting, and hot chamber die casting. These processes can all produce medium plates of specific shapes from magnesium alloys.

[0094] In some possible implementations, at least one of the magnesium alloys with a Zn content ≥ 5% is used for the medium plate.

[0095] In some possible implementations, the magnesium alloy in the medium plate contains the following components by mass percentage: Zn content of 7% to 9%, Zr content of 1% to 3%, rare earth element content of 0.1% to 0.5%, Al content of 0.1% to 0.7%, Ti element content of 0.05% to 0.3%, total impurity element content of <0.5%, and the balance being Mg.

[0096] In some possible implementations, the middle plate comprises ZK60 magnesium alloy.

[0097] In some possible implementations, the rare earth element includes at least one of lanthanum (La), cerium (Ce), yttrium (Y), and scandium (Sc).

[0098] In some possible implementations, the thermal conductivity of the magnesium alloy in the middle plate is 110 W / mk to 160 W / mk.

[0099] The beneficial effects of the magnesium alloy features in the above embodiments of this application have been discussed in the foregoing and will not be repeated here.

[0100] In step S30 above:

[0101] In some possible implementations, the method of fixing the frame to the perimeter of the middle plate includes friction stir welding. Friction stir welding refers to using the heat generated by the friction between a high-speed rotating welding tool and the workpiece to locally melt the materials being welded (i.e., the frame material and the middle plate material). As the welding tool moves forward along the welding interface (i.e., the interface between the frame and the middle plate), the plasticized material flows from the front to the rear of the welding tool under the rotational friction force, forming a dense solid-phase weld under the pressure of the welding tool. The main advantages of using friction stir welding in this case include: minimal changes in the microstructure of the heat-affected zone of the weld joint, relatively low residual stress, and less deformation of the welded workpiece; the ability to complete long welds, large cross-sections, and welds at different locations in one operation, resulting in high joint height; convenient operation, enabling mechanization and automation, simple equipment, low energy consumption, high efficiency, and low requirements for the working environment; no need to add welding wire, no need to remove oxide film before welding aluminum alloys, no need for shielding gas, resulting in low cost; and a safe, pollution-free, smoke-free, and radiation-free welding process.

[0102] In some possible implementations, the width of the stirring zone in friction stir welding is 3mm to 10mm; the width of this area is the diameter of the stirring head in friction stir welding, and this width range can meet the manufacturing requirements of different types of electronic device frames. When friction stir welding is used, the stirring zone in friction stir welding is the welding area between the frame and the middle plate.

[0103] In some possible implementations, after the frame is fixedly connected to the perimeter of the middle plate, the processing method includes CNC machine tool machining. According to a pre-programmed machining program, the CNC device and servo system control the machine tool spindle and feed actuators to realize the relative movement or position change between the tool and the workpiece, thereby completing the machining of the electronic device frame and obtaining a high-precision electronic device frame with a complex three-dimensional structure.

[0104] In some possible implementations, in the welding zone between the frame and the middle plate, the concentration of magnesium-based composite material increases from the middle plate towards the frame, while the concentration of magnesium alloy decreases from the middle plate towards the frame. Since the frame is made of magnesium-based composite material, the concentration of magnesium-based composite material is higher closer to the frame; similarly, since the middle plate is made of high thermal conductivity magnesium alloy, the concentration of high thermal conductivity magnesium alloy is higher closer to the middle plate.

[0105] This application provides an electronic device that includes the electronic device frame provided in the above-described embodiments of this application or the electronic device frame prepared by the above-described preparation method of this application.

[0106] The electronic device in this application embodiment includes the aforementioned electronic device frame. The frame is made of high-modulus magnesium-based composite material as the border and high thermal conductivity magnesium alloy as the middle plate, with the two fixedly connected. It also has properties such as high strength, high modulus, and high thermal conductivity, which not only enhances the overall structural stability of the electronic device, but also reduces the occurrence of overheating, reduces the risk of damage to internal components due to thermal stress, extends the service life of the electronic device, and is also conducive to the lightweight design of the electronic device.

[0107] In some possible implementations, the electronic device includes a mobile terminal device. Examples of mobile terminal devices include mobile phones, tablets, in-vehicle computers, smartwatches, etc.

[0108] The following description uses specific embodiments. These embodiments are exemplary and are only used to explain this application, and should not be construed as limiting the application. Where specific techniques or conditions are not specified in the embodiments, they are performed according to the techniques or conditions described in the literature in this field or according to the product instructions. Reagents or instruments used, unless otherwise specified, are all commercially available conventional products.

[0109] Example 1

[0110] This application provides a mobile phone mid-frame, the structural schematic of which is shown in Figure 1, including the following manufacturing steps:

[0111] 1. Using AZ31B magnesium alloy as the matrix, it is melted and doped with SiC particles with a particle size D50 of about 20 micrometers (the value of 50% is lower). The doping ratio is 15% by mass. The process is to heat from room temperature to 720°C, then stir for 50 minutes at a speed of 1050 rpm, and then cool to room temperature to form a magnesium-based composite material block with an elastic modulus of 65 GPa.

[0112] 2. Place the above block in an extruder for extrusion molding to form a cuboid shape with dimensions of 10mm*90mm, and then cut it into blocks of 230mm*90mm*10mm; cut the middle of the block to form a hollow structure, the area of ​​the middle plate is shown in Figure 1, and obtain the frame.

[0113] 3. Using ZK60 magnesium alloy with a thermal conductivity of 115 W / mk as the base material, cut it into the part shown in the middle plate of Figure 1 to obtain the middle plate.

[0114] 4. The frame made of magnesium-based composite material and the middle plate made of high thermal conductivity magnesium alloy are connected by friction stir welding. The stirring zone width of the friction stir welding is 5mm, which constitutes the welding zone between the frame and the middle plate. In the welding zone, the concentration of magnesium-based composite material increases from the middle plate to the frame, and the concentration of magnesium alloy decreases from the middle plate to the frame. This forms an integrated mobile phone middle frame blank.

[0115] 5. The mobile phone frame blank is machined by CNC machine tool to obtain a mobile phone frame structural part with a complex three-dimensional shape.

[0116] Example 2

[0117] This application provides a mobile phone mid-frame, the structural schematic of which is shown in Figure 1, including the following manufacturing steps:

[0118] 1. Using AZ91D magnesium alloy as the matrix, it is melted and doped with SiC particles with a particle size D50 of about 10 micrometers (50% of the particles have a value of less than 10 micrometers). The doping ratio is 13% by mass. The process is to heat the mixture from room temperature to 720°C, then stir it for 50 minutes at a speed of 1050 rpm, and then cool it to room temperature to form a magnesium-based composite material block with an elastic modulus of 63 GPa.

[0119] 2. Place the above-mentioned block into a squeeze casting machine for casting to form a magnesium-based composite material frame structure for the mobile phone frame, as shown in Figure 1, to obtain the frame.

[0120] 3. Using a magnesium alloy with a thermal conductivity of 113 W / mk as the matrix, cut it into the portion shown in the middle plate of Figure 1 to obtain the middle plate. The composition of the magnesium alloy includes: 8% Zn, 2% Zr, 0.3% rare earth elements, 0.4% Al, 0.2% Ti, and the total content of other impurities is <0.5%, with the balance being magnesium.

[0121] 4. The frame made of magnesium-based composite material and the middle plate made of high thermal conductivity magnesium alloy are joined by friction stir welding. The width of the friction stir welding zone is 7mm. This zone constitutes the welding zone between the frame and the middle plate. In the welding zone, the concentration of magnesium-based composite material increases from the middle plate to the frame, while the concentration of magnesium alloy decreases from the middle plate to the frame. This forms an integrated mobile phone middle frame blank.

[0122] 5. The mobile phone frame blank is machined by CNC machine tool to obtain a mobile phone frame structural part with a complex three-dimensional shape.

[0123] Example 3

[0124] This application provides a mobile phone mid-frame, the structural schematic of which is shown in Figure 1, including the following manufacturing steps:

[0125] 1. Using a high-strength magnesium alloy as the matrix, with a yield strength >350MPa, the magnesium alloy composition includes: 8% Al, 3% lanthanum, 7% cerium, and the remainder being Mg, with impurities not exceeding 1%. Magnesium alloy powder with a particle size D50 <15 micrometers is prepared, and TiB2 particles with a D50 <2 micrometers are incorporated at a doping ratio of 20%. The two are then mixed uniformly under vacuum. The mixed powder is degassed, isostatically pressed, and heat-treated to obtain a TiB2-doped magnesium-based composite material with an elastic modulus of 70 GPa.

[0126] 2. Place the above block in an extruder for extrusion molding to form a cuboid shape with dimensions of 10mm*90mm, and then cut it into blocks of 230mm*90mm*10mm; cut the middle of the block to form a hollow structure, the area of ​​the middle plate is shown in Figure 1, and obtain the frame.

[0127] 3. Using ZK60 magnesium alloy with a thermal conductivity of 115 W / mk as the base material, cut it into the part shown in the middle plate of Figure 1 to obtain the middle plate.

[0128] 4. The frame made of magnesium-based composite material and the middle plate made of high thermal conductivity magnesium alloy are connected by friction stir welding. The stirring zone width of the friction stir welding is 7mm, which constitutes the welding zone between the frame and the middle plate. In the welding zone, the concentration of magnesium-based composite material increases from the middle plate to the frame, and the concentration of magnesium alloy decreases from the middle plate to the frame. This forms an integrated mobile phone middle frame blank.

[0129] 5. The mobile phone frame blank is machined by CNC machine tool to obtain a mobile phone frame structural part with a complex three-dimensional shape.

[0130] Example 4

[0131] This application provides a mobile phone mid-frame, which differs from Embodiment 1 in that the doped particles in the frame are replaced with Al2O3 instead of SiC, and the frame's elastic modulus is 60 GPa. All other materials and preparation conditions are the same as in Embodiment 1.

[0132] Example 5

[0133] This application provides a mobile phone mid-frame, which differs from Embodiment 1 in that the doped particles in the frame are replaced with graphite instead of SiC, and the elastic modulus of the frame is 63 GPa. All other materials and preparation conditions are the same as in Embodiment 1.

[0134] Example 6

[0135] This application provides a mobile phone mid-frame, which differs from Embodiment 1 in that the doped particles in the frame are replaced with graphene instead of SiC, and the elastic modulus of the frame is 65 GPa. All other materials and preparation conditions are the same as in Embodiment 1.

[0136] Example 7

[0137] This application provides a mobile phone mid-frame, which differs from Embodiment 1 in that the SiC particles doped in the frame have a doping content of 5% and the frame's elastic modulus is 55 GPa.

[0138] Example 8

[0139] This application provides a mobile phone mid-frame, which differs from Embodiment 1 in that the SiC particles doped in the frame have a doping content of 30%, and the frame's elastic modulus is 70 GPa.

[0140] Example 9

[0141] This application provides a mobile phone mid-frame, which differs from Embodiment 1 in that the SiC particles doped in the frame have a doping content of 31% and the frame's elastic modulus is 71 GPa.

[0142] Example 10 This application provides a mobile phone mid-frame, which differs from Example 1 in that: the SiC particles doped in the frame have a doping content of 4%, and the frame's elastic modulus is 54 GPa.

[0143] Example 11

[0144] This application provides a mobile phone mid-frame, which differs from Embodiment 1 in that the particle size D50 of the SiC particles doped in the frame is 5μm and the elastic modulus of the frame is 60GPa.

[0145] Example 12

[0146] This application provides a mobile phone mid-frame, which differs from Embodiment 1 in that the particle size D50 of the SiC particles doped in the frame is 15μm and the elastic modulus of the frame is 60GPa.

[0147] Comparative Example 1

[0148] This comparative example provides a mobile phone frame that differs from Example 1 in that the frame does not contain SiC particles, and the elastic modulus of the AZ31B magnesium alloy is 45 GPa.

[0149] Comparative Example 2

[0150] This comparative example provides a mobile phone mid-frame, which differs from Example 1 in that the mid-frame uses AZ91D magnesium alloy with a thermal conductivity of 59W / mk.

[0151] Comparative Example 3

[0152] This comparative example provides a mobile phone mid-frame, which differs from Example 1 in that both the frame and the mid-plate are made of AZ31B with an elastic modulus of 45GPa and 54W / mk.

[0153] Comparative Example 4

[0154] This comparative example provides a mobile phone mid-frame, which differs from Example 1 in that: both the frame and the mid-plate are made of 6013 aluminum alloy with an elastic modulus of 70 GPa and 160 W / mk.

[0155] The bezel, mid-plate, and overall mobile phone frame in each of the above embodiments and comparative examples were tested respectively:

[0156] 1. Elastic modulus test method: Measured according to national standard GB / T 22315-2008;

[0157] 2. Thermal conductivity test method: Measured according to national standard GB / T 3651-2008;

[0158] 3. Three-point bending stiffness test method: Three-point bending stiffness is a physical quantity describing a material's ability to resist bending deformation in a three-point bending test. In a three-point bending test, the specimen is usually placed on two supports, and a force perpendicular to the specimen's cross-section is applied in the middle of the specimen, causing it to bend. By measuring the specimen's deflection (i.e., the amount of deformation of the specimen under the applied force) and the applied force, the bending stiffness of the material can be calculated. The formula for calculating the three-point bending stiffness may vary depending on the shape and size of the specimen. For a rectangular cross-section specimen, assuming its length is L, width is b, and height is h, and a deflection d is produced under the action of an applied force P, then the formula for calculating the bending stiffness K is: K = P * L / (3 * d).

[0159] 4. Weight reduction rate test method: Weight of the mobile phone frame prepared in the example / Weight of the pure aluminum alloy mobile phone frame in Comparative Example 4 * %;

[0160] 5. Drop Test Method: According to national standards GB / T 2423.7-2018, GB / T 4857.1-2019, GB / T 4857.23-2021, and GB / T 4857.5-1992, the test method involves lifting the product to 0.5 meters, 0.8 meters, 1 meter, or 1.5 meters and conducting natural and accelerated drop tests at different angles. Table 1 below shows the drop test results for 1.1 meters, 1 meter, 0.8 meters, or 0.5 meters, indicating that the phone frame can pass the natural and accelerated drop tests at 1.1 meters, 1 meter, 0.8 meters, or 0.5 meters respectively.

[0161] The test results are shown in Table 1 below:

[0162] Table 1

[0163] As shown in the test data in Table 1, the mobile phone frame prepared in this embodiment, using high-modulus magnesium-based composite material as the frame and high thermal conductivity magnesium alloy as the middle plate, possesses high strength, high elastic modulus, and high thermal conductivity. Its three-point bending stiffness is significantly higher than that of the mobile phone frames provided in Comparative Examples 1-3. Furthermore, the drop test performance of the mobile phone frame provided in this embodiment is essentially equivalent to that of the pure aluminum alloy mobile phone frame provided in Comparative Example 4, and superior to that of the mobile phone frames provided in Comparative Examples 1-3. This not only enhances the overall structural stability of the mobile phone frame but also reduces overheating, extends the lifespan of the mobile phone, and better meets the application requirements of electronic devices. Moreover, compared to the pure aluminum alloy mobile phone frame provided in Comparative Example 4, the weight reduction rate of the mobile phone frame in this embodiment exceeds 33%, which is beneficial for lightweight design of electronic devices.

[0164] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. The protection scope of this application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims. Therefore, the protection scope of this application should be determined by the protection scope of the claims.

Claims

1. An electronic device frame, characterized by comprising: The electronic device frame includes a middle plate and a frame fixedly connected around the middle plate; wherein, the frame is made of magnesium-based composite material, the magnesium-based composite material is doped with powder material reinforcement, and the elastic modulus of the magnesium-based composite material is not less than 55 GPa; the middle plate is made of magnesium alloy with a thermal conductivity of not less than 90 W / mk.

2. The electronic device frame of claim 1, wherein The mass percentage of the powder material reinforcement doped in the magnesium-based composite material is 5% to 30%. And / or, the powder material reinforcement includes at least one of SiC, TiB2, Al2O3, graphite, and graphene; And / or, the particle size D50 of the powder material reinforcement is greater than 0 and not higher than 20 μm.

3. The electronic device frame of claim 1 or 2, wherein The magnesium-based composite material contains the following components by mass percentage: Al content of 9.5% to 10.5%, Zn content of 0.91% to 1.35%, Mn content of 0.41% to 0.9%, Si content of ≤0.1%, total impurity element content of <0.1%, and the balance being Mg.

4. The electronic device frame of claim 1 or 2, wherein In the magnesium-based composite material, the magnesium alloy substrate includes at least one of AZ31B magnesium alloy and AZ91D magnesium alloy.

5. The electronic device frame of claim 1 or 2, wherein The middle plate includes at least one magnesium alloy with a Zn content of ≥5%.

6. The electronic device frame of claim 5, wherein The magnesium alloy in the medium plate contains the following components by mass percentage: Zn content of 7% to 9%, Zr content of 1% to 3%, rare earth element content of 0.1% to 0.5%, Al content of 0.1% to 0.7%, Ti element content of 0.05% to 0.3%, total impurity element content of <0.5%, and the balance being Mg; And / or, the middle plate comprises ZK60 magnesium alloy.

7. The electronic device frame of claim 6, wherein The rare earth elements include at least one of lanthanum, cerium, yttrium, and scandium.

8. The electronic device frame of any one of claims 1, 2, 6, or 7, wherein, The elastic modulus of the magnesium-based composite material is 60 GPa to 80 GPa; And / or, the thermal conductivity of the magnesium alloy in the middle plate is 110 W / mk to 160 W / mk.

9. The electronic device frame of any one of claims 1, 2, 6, or 7, wherein, The electronic device frame includes at least one of a mobile phone frame, a tablet computer frame, and a smartwatch frame.

10. A method for producing an electronic device frame, characterized by Includes the following steps: A magnesium-based composite material doped with powder material reinforcement is obtained and used to make a frame; the elastic modulus of the magnesium-based composite material is not less than 55 GPa; A magnesium alloy with a thermal conductivity of not less than 90 W / mk is used to make a medium plate; The frame is fixedly connected to the perimeter of the middle plate and processed to form the electronic device frame.

11. The method of producing an electronic equipment frame according to claim 10, wherein The frame is prepared using the magnesium-based composite material in at least one of the following methods: stir casting, squeeze casting, semi-solid die casting, and hot chamber die casting. And / or, the method of preparing the middle plate using the magnesium alloy includes at least one of: stir casting, squeeze casting, semi-solid die casting, and hot chamber die casting.

12. The method for producing an electronic equipment frame according to claim 10 or 11, wherein The method of fixing the frame to the perimeter of the middle plate includes friction stir welding; And / or, the processing method includes CNC machine tool processing.

13. The method of producing an electronic equipment frame according to claim 12, wherein The width of the stirring zone in the friction stir welding is 3mm to 10mm; And / or, in the welding area between the frame and the middle plate, the concentration of the magnesium-based composite material increases along the direction from the middle plate to the frame, and the concentration of the magnesium alloy decreases along the direction from the middle plate to the frame.

14. An electronic device, comprising: The electronic device comprises the electronic device frame as claimed in any one of claims 1 to 9 or the electronic device frame prepared by the preparation method as claimed in claims 10 to 13.

15. The electronic device of claim 14, wherein, The electronic device comprises a mobile terminal device.

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