Housing, electronic device and preparation method for housing

Abstract

Provided in the present application are a housing, an electronic device, and a preparation method for the housing. The housing is provided with a middle plate and a frame, the frame surrounding and being connected to the outer peripheral side of the middle plate. The housing comprises a first part and a second part, and the first part is connected to the second part. The material of the first part is a metal alloy, the material of the second part is a metal matrix composite material, and the connection interface between the first part and the second part is a metallurgical bonding interface. The metal matrix of the metal alloy in the first part is the same as the metal matrix of the metal matrix composite material in the second part, or the metal matrix of the metal alloy in the first part and the metal matrix of the metal matrix composite material in the second part are respectively any two of an aluminum matrix, a titanium matrix, and a magnesium matrix. The housing provided in the present application has strong comprehensive performance, and can take into account diversified requirements such as reliable strength, light weight, and thinning of the middle plate.

Description

Housing, electronic device and method for manufacturing housing

[0001] This application claims priority to Chinese Patent Application No. 202411200168.7, filed on August 29, 2024, entitled “Housing, Electronic Device and Method for Manufacturing Housing”, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of electronic device technology, and in particular to a housing, an electronic device, and a method for manufacturing the housing. Background Technology

[0003] The casings of electronic devices, such as the mid-frame of mobile phones, are commonly made of aluminum alloy. Aluminum alloys offer advantages such as light weight, high strength, and good machinability, making them the most widely used material in mid-to-high-end products. Common aluminum alloy mid-frames are unibody designs; for example, the frame and mid-plate of a mobile phone mid-frame are machined from the same aluminum alloy sheet using CNC machine tools. This method results in mid-frames with insufficient strength and modulus of elasticity, making them prone to significant deformation under pressure or impact, potentially causing the front screen glass to shatter. In current designs, to ensure the reliability of the aluminum alloy mid-frame, the thickness of the mid-plate is often increased to achieve higher strength and modulus of elasticity, especially in the large battery compartment area. This prevents the mid-plate from being truly thinner. Currently, the thinnest thickness in the battery compartment area of ​​a mobile phone mid-frame is 0.2mm, making further thickness reduction impossible to increase battery capacity or further reduce the weight of the mid-frame, contradicting the design philosophy of thinner and lighter electronic devices. Some manufacturers use stainless steel casings, which offer sufficient strength and modulus of elasticity, but the PVD (Physical Vapor Deposition) coating on its surface is easily scratched. Furthermore, stainless steel is approximately three times denser than aluminum alloys, thus offering no weight reduction benefits.

[0004] Currently, some manufacturers still use a combination of aluminum alloy and other materials to manufacture the shell. This involves processing different parts of the shell using different materials and then joining the two materials together using methods such as friction stir welding. Compared to a one-piece shell, this processing method is more flexible, allowing for different material requirements in different parts of the shell and improving its overall performance. However, this method inevitably affects the structural strength of the joint area between the two materials. During the joining process, excessive thermal stress concentration can cause deformation, affecting the dimensional yield of the shell and making it difficult to meet quality requirements.

[0005] It is evident that the overall performance of the shell in the existing technology is poor, making it difficult to simultaneously meet diverse requirements such as reliable mechanical properties, lightweighting, and thinning of the middle plate. Summary of the Invention

[0006] This application provides a housing, an electronic device, and a method for manufacturing the housing, which solves the problem that the overall performance of the housing in the prior art is not good, and it is difficult to meet the diverse needs such as reliable mechanical properties, lightweighting, and thinning of the middle plate.

[0007] A first aspect of this application provides a housing having a middle plate and a frame, the frame being connected to the outer periphery of the middle plate. The housing includes a first part and a second part, the first part being connected to the second part. The first part is made of a metal alloy, the second part is made of a metal matrix composite material, and the interface between the first part and the second part is a metallurgical bonding interface. The metal matrix of the metal alloy in the first part is the same as the metal matrix of the metal matrix composite material in the second part, or the metal matrix of the metal alloy in the first part and the metal matrix of the metal matrix composite material in the second part are any two different types selected from aluminum-based, titanium-based, and magnesium-based materials.

[0008] The first part constitutes the entire frame, and the second part constitutes all areas of the middle plate. Alternatively, the first part constitutes the entire frame and a portion of the middle plate, and the second part constitutes the remaining portion of the middle plate excluding that portion.

[0009] The housing provided in this application comprises a first part and a second part, which are made of different materials, making the housing material more diversified. This allows for targeted material selection based on the location, area, and shape of the first and second parts, meeting the different structural material requirements of different parts of the housing and improving its overall performance. The entire frame of the housing belongs to the first part, while the middle plate can belong entirely to the second part, or a portion of it can belong to the first part and another portion to the second part. In other words, at least a portion of the frame and the middle plate are made of different materials. Since the frame and the middle plate are different parts of the housing, their material requirements also differ. For example, when the housing is a middle frame, the frame, as the external framework of the electronic device, requires not only strength and hardness but also wear resistance and ease of surface treatment to maintain a good tactile feel and appearance during use. The middle plate, as the supporting structure for internal components, needs sufficient strength and rigidity. Furthermore, material selection should focus on heat dissipation, corrosion resistance, and lightweight properties. Dividing the frame and the middle plate (at least a portion of which) into the first and second parts respectively precisely meets their different material selection requirements.

[0010] Furthermore, the first part is made of a metal alloy, and the second part is made of a metal matrix composite. Metal alloys offer excellent comprehensive performance and come in a wide variety, meeting the material selection requirements for the mid-frame. Metal matrix composites are composite materials with metals or alloys as the matrix and fibers, whiskers, particles, etc., as reinforcements. They retain the properties of the metal itself while possessing the comprehensive characteristics of composite materials. Through optimized combinations of different matrices and reinforcements, composite materials with various special properties and excellent comprehensive performance can be designed to meet the material selection requirements for the mid-plate. Metal alloys and metal composites also have the advantages of being lightweight and high-strength, which can also benefit weight reduction and mid-plate thinning.

[0011] The interface between the first and second parts is a metallurgical bonding interface, meaning the first and second parts are joined using a metallurgical bonding method. Compared to mechanical bonding, the mixing of the two materials is more uniform and smoother at the metallurgical bonding interface, resulting in a stronger bond and higher reliability. Furthermore, some metallurgical bonding techniques can be performed under relatively uniform ambient temperatures, ensuring uniform heating of the entire shell, avoiding stress concentration, reducing shell deformation, and improving dimensional yield. If the metal alloy in the first part and the metal matrix composite material in the second part use the same metal matrix, the chemical properties of the two materials are relatively similar, leading to more complete bonding and diffusion at the interface, resulting in a stronger bond. Alternatively, the metal matrix of the metal alloy in the first part and the metal matrix composite material in the second part can be any two different metals selected from aluminum, titanium, and magnesium. This can be understood as the two parts having different metal matrices, but both using aluminum, titanium, or magnesium. In this case, the chemical properties of the two metal matrices are relatively similar, also achieving a good bonding effect.

[0012] As can be seen, the shell provided by the embodiments of this application has strong comprehensive performance and can take into account diverse requirements such as reliable mechanical performance, lightweight, and thinning of the middle plate.

[0013] In one possible implementation, the first and second parts are joined by isostatic pressing (OSP). During OSP, both parts are subjected to uniform pressure and heat, resulting in consistent expansion and contraction, minimal deformation of the billet, and higher dimensional yield of the shell. Furthermore, OSP can densify the material, helping to protect its microstructure and properties.

[0014] In one possible implementation, when the metal matrix of the metal alloy in the first part is the same as the metal matrix of the metal matrix composite material in the second part, the material of the first part is one of aluminum alloy, titanium alloy, and magnesium alloy, and the material of the second part is one of aluminum matrix composite material, titanium matrix composite material, and magnesium matrix composite material.

[0015] In one possible implementation, when the first part is made of aluminum alloy and the second part is made of aluminum-based composite material:

[0016] The material of the first part is 6-series aluminum alloy, while the base material of the aluminum-based composite material in the second part is 5-series, 6-series, or 7-series aluminum alloy.

[0017] Alternatively, the first part may be made of 7-series aluminum alloy, while the base material of the aluminum-based composite material in the second part may be 6-series or 7-series aluminum alloy.

[0018] Using the above scheme, the first part is made of aluminum alloy, and the second part is made of aluminum-based composite material. The aluminum-based series of the two materials are the same or similar, resulting in more thorough mixing of the microparticles at the metallurgical interface, further improving reliability. Aluminum alloys and aluminum-based composite materials also possess advantages such as low density, high strength, wear resistance, fatigue resistance, and high electrical and thermal conductivity, exhibiting excellent overall performance.

[0019] In one possible implementation, the first part is made of titanium alloy, and the substrate of the aluminum-based composite material in the second part is a 6-series or 7-series aluminum alloy.

[0020] Using the above scheme, the first part is made of titanium alloy, and the second part is made of 6-series or 7-series aluminum-based composite material. Although the metal bases of the two materials are different, their chemical properties are similar. The micro-particles of the two materials are mixed more thoroughly at the metallurgical interface, resulting in higher reliability. Furthermore, they can be better matched in heat treatment and other processing processes, reducing processing difficulty.

[0021] In one possible implementation, the second part is made of fiber-reinforced metal matrix composites or particle-reinforced metal matrix composites. By adding reinforcements to the metal matrix composite, specific properties can be optimized while maintaining the original material characteristics.

[0022] In one possible implementation, when the material of the second part is a particle-reinforced metal matrix composite, the reinforcing material of the particle-reinforced metal matrix composite is one, two, or three of the following: SiC, Al2O3, B4C, TiB2, graphene, carbon nanotubes, graphite, and diamond.

[0023] In one possible implementation, when the material of the second part is a particle-reinforced aluminum matrix composite, and the reinforcing material of the particle-reinforced aluminum matrix composite is SiC:

[0024] SiC particles with a diameter of 0-0.2 μm are dispersed in an aluminum alloy substrate at a volume fraction of 0-5%.

[0025] Alternatively, SiC particles with a diameter of 0.5μm-1μm are dispersed in an aluminum alloy substrate at a volume fraction of 0-10%.

[0026] Alternatively, SiC particles with a diameter of 3μm-20μm are dispersed in an aluminum alloy substrate at a volume fraction of 8-25%.

[0027] By adopting the above scheme, it is possible to formulate a particle-reinforced aluminum matrix composite material with optimal overall performance.

[0028] In one possible implementation, the housing further includes an anodized layer, which is applied to the outer surface of the first portion. The anodized layer provides an attractive appearance to the surface of the housing and is resistant to discoloration, wear, and corrosion, does not easily peel off, and has good heat dissipation performance.

[0029] A second aspect of this application provides an electronic device including a housing, the housing including any of the housings provided in the above embodiments.

[0030] The electronic device provided in this application has excellent overall performance of the casing, high overall reliability, and is conducive to achieving a thin and light design with long battery life.

[0031] In one possible implementation, the electronic device further includes a battery assembly housed within the housing. The housing is a mid-frame, and the area of ​​the mid-plate of the housing corresponding to the battery assembly is the battery compartment area. The electronic device also includes a rear cover, the outer periphery of which is connected to the frame; wherein the mid-plate and the rear cover are spaced apart, or the mid-plate can be reused as the rear cover.

[0032] In one possible implementation, another part of the middle plate includes the battery compartment area of ​​the middle plate.

[0033] Using the above solution, the battery compartment area of ​​the middle plate is made of metal matrix composite material. While meeting the requirements of high strength and high elastic modulus, it can also reduce the thickness of the battery compartment area, leaving more space for battery installation, thereby increasing battery capacity.

[0034] In one possible implementation, the electronic device further includes a hinge mechanism, with the housing serving as the hinge cover for the hinge mechanism. In the thickness direction of the hinge mechanism, a portion of the middle plate is stacked with another portion of the middle plate.

[0035] Using the above solution, the electronic device is a foldable electronic device with high strength in its hinge area, which can withstand high-frequency opening and closing of the device.

[0036] A third aspect of this application provides a method for preparing a housing, wherein the housing is the housing provided in any of the above embodiments; the preparation method includes:

[0037] A first prefabricated component is provided; wherein the first prefabricated component has a filling space and the material of the first prefabricated component is a metal alloy.

[0038] Metal matrix composite powder is filled into the filling space of the first preform. The first preform includes an annular frame preform with a hollowed-out filling space surrounding it; or, the first preform includes an annular frame preform and a first middle plate preform adjacent to the inner periphery of the frame preform, with the frame preform and the first middle plate preform surrounding a hollowed-out filling space.

[0039] A first preform filled with metal matrix composite powder is subjected to isostatic pressing sintering to obtain a shell preform. The shell preform includes the first preform after isostatic pressing sintering and a second preform formed of metal matrix composite powder. The first preform and the second preform are connected, and the interface between them is a metallurgical bonding interface.

[0040] The shell is manufactured by processing the shell preforms. The first part of the shell is made from the first part of the shell preforms, and the second part of the shell is made from the second part of the shell preforms.

[0041] The shell preparation method provided in this application embodiment can improve the overall performance of the shell and has advantages such as high strength, high elastic modulus, and lightweight.

[0042] In one possible implementation, the step of isostatically pressing and sintering the first portion of the preform filled with metal matrix composite powder to obtain the shell preform includes:

[0043] The first part of the preform, which is filled with metal matrix composite powder, is cold isostatically pressed to form a cold-pressed preform.

[0044] The cold-pressed blank is placed in the hot-pressing mold.

[0045] The hot pressing mold containing the cold-pressed preform is vacuum degassed and then sealed.

[0046] The hot pressing mold containing the cold-pressed preform after vacuum degassing is then subjected to hot isostatic pressing sintering to form a combination of the hot pressing mold and the hot-pressed preform.

[0047] By processing the combination of the hot pressing mold and the hot pressing blank, the hot pressing mold is removed to obtain the hot pressing blank.

[0048] The hot-pressed blank is heat-treated to obtain the shell preform.

[0049] In one possible implementation, during the cold isostatic pressing step, the temperature is room temperature, the pressure is 3MPa-15MPa, and the holding time is 5min-45min. During the hot isostatic pressing sintering step, the temperature is 580℃-620℃, the pressure is 5MPa-30MPa, and the holding time is 10min-60min.

[0050] In one possible implementation, the step of heat-treating the hot-pressed blank to obtain the shell preform includes:

[0051] The hot-pressed preform is subjected to solution treatment at a temperature of 450℃-500℃ for 1-4 hours.

[0052] The hot-pressed blank after solution treatment is then quenched in cold water.

[0053] The hot-pressed blank, after being quenched in cold water, is subjected to artificial aging treatment at a temperature of 120℃-180℃ for 2h-24h to obtain the shell preform.

[0054] In one possible implementation, the first preform is obtained by cutting a metal alloy profile. In the step of filling the filling space of the first preform with metal matrix composite powder, the metal matrix composite powder completely fills the filling space.

[0055] In one possible implementation, the step of filling the filling space of the first preform with metal matrix composite powder includes the following steps for preparing the filling metal matrix composite powder:

[0056] The reinforcing preform powder is pretreated and surface modified to obtain the reinforcing material powder.

[0057] Metal matrix composite powder is prepared by mixing reinforcing material powder with a base material powder containing a metal matrix.

[0058] In one possible implementation, the steps of fabricating the shell by processing the shell preform include:

[0059] The first prefabricated part, which is connected to the second prefabricated part, is sequentially subjected to one CNC machining, T-processing, nano-injection molding, two CNC machining, grinding and polishing, sandblasting, and anodizing to obtain the shell. Attached Figure Description

[0060] Figure 1 is a three-dimensional structural schematic diagram of the first embodiment of the electronic device of this application;

[0061] Figure 2 is an exploded structural diagram of the first embodiment of the electronic device of this application;

[0062] Figure 3a is a cross-sectional schematic diagram of the first embodiment of the electronic device of this application;

[0063] Figure 3b is a second cross-sectional schematic diagram of the first embodiment of the electronic device of this application;

[0064] Figure 4 is a schematic diagram of the mid-frame structure of the electronic device according to the first embodiment of this application;

[0065] Figure 5 is a schematic diagram of the middle frame in the first reference design;

[0066] Figure 6 is a schematic diagram of the middle frame in the second reference design;

[0067] Figure 7 is a schematic diagram of the middle frame in the third reference design;

[0068] Figure 8 is a structural schematic diagram of the middle frame in the fourth reference design;

[0069] Figure 9 is a schematic diagram of the mechanical bonding interface of friction stir welding;

[0070] Figure 10a is a schematic diagram of the shell structure according to an embodiment of this application;

[0071] Figure 10b is a schematic diagram of the shell structure according to an embodiment of this application;

[0072] Figure 10c is a schematic diagram of the structure of the shell in an embodiment of this application;

[0073] Figure 11 is a schematic diagram of the metallurgical bonding interface of isostatic pressing sintering;

[0074] Figure 12a is a three-dimensional structural diagram of the second embodiment of the electronic device of this application in the unfolded state;

[0075] Figure 12b is a three-dimensional structural diagram of the second embodiment of the electronic device of this application in a folded state;

[0076] Figure 12c is a schematic diagram of the rear structure of the electronic device according to a second embodiment of the present application;

[0077] Figure 13a is a schematic diagram of the structure of the shaft cover in the second embodiment of the electronic device of this application;

[0078] Figure 13b is a schematic diagram of the cross-sectional structure in the OO direction of Figure 13a;

[0079] Figure 14a is a flowchart of the preparation method of the shell according to an embodiment of this application;

[0080] Figure 14b is a schematic diagram of the steps of the shell preparation method according to an embodiment of this application, wherein the shell is a middle frame;

[0081] Figure 14c is a schematic diagram of the steps of the shell preparation method according to an embodiment of this application, wherein the shell is a shaft cover;

[0082] Figure 15 is a flowchart of the shell preparation method according to an embodiment of this application;

[0083] Figure 16a is a flowchart of the preparation method of the shell according to an embodiment of this application;

[0084] Figures 16b-16c are schematic diagrams of the isostatic pressing sintering steps in the preparation method of the shell according to the embodiments of this application;

[0085] Figure 17a is a flowchart of the preparation method of the shell according to an embodiment of this application;

[0086] Figure 17b is a schematic diagram of the heat treatment steps in the shell preparation method of the embodiment of this application;

[0087] Figure 18 is a flowchart of the shell preparation method according to an embodiment of this application;

[0088] Figure 19 is a flowchart of the shell preparation method according to an embodiment of this application;

[0089] Figure 20 is a flowchart (seven) of the shell preparation method according to an embodiment of this application;

[0090] Figure 21 is a flowchart of the shell preparation method according to an embodiment of this application;

[0091] Figure 22 is a flowchart of the shell preparation method according to an embodiment of this application;

[0092] Figure 23 is a flowchart of the preparation method of the shell according to an embodiment of this application.

[0093] Explanation of reference numerals in the attached drawings: 100 - Electronic device; 200 - Housing; 201 - First part; 202 - Second part; 203 - Metallurgical bonding interface; 204 - Anodized layer; 1 - Outer shell; 11 - Middle frame; 111 - Frame; 112 - Middle plate; 112A - Partial area; 112B - Another partial area; 112C - Battery compartment area; 12 - Rear cover; 13 - Battery assembly; 14 - Circuit board; 15 - Display screen; 151 - First part; 152 - Second part; 153 - Foldable part; 2 - Housing assembly; 21 - First housing; 22 - Second housing; 23 - Hinge mechanism; 24 - Axle cover; 241 - Frame; 242 - Middle plate; 242A - Partial area; 242B - Another partial area; X - Thickness direction of the electronic device; Y - Thickness direction of the hinge mechanism; 3-First part preform; 31-Filling space; 32-Metal matrix composite powder; 4-Shell preform; 5-Second part preform; 61-Cold-pressed blank; 62-Hot-pressing mold; 63-Hot-pressed blank; 64-Graphite paper. Detailed Implementation

[0094] The following specific embodiments illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. Although the description of this application will be presented in conjunction with some embodiments, this does not mean that the features of this application are limited to this embodiment. On the contrary, the purpose of describing the application in conjunction with embodiments is to cover other options or modifications that may be derived based on the claims of this application. To provide a thorough understanding of this application, many specific details will be included in the following description. This application may also be implemented without using these details. Furthermore, to avoid confusion or obscuring the focus of this application, some specific details will be omitted in the description. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other.

[0095] It should be noted that in this specification, similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0096] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," "outer," "top," and "bottom," etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0097] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" 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; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0098] In the description of this application, it should be noted that the mutual perpendicularity in this application is not absolute perpendicularity. Approximate perpendicularity due to processing errors and assembly errors (e.g., the included angle between two structural features is 89.9°) is also within the scope of mutual perpendicularity in this application. Similarly, the mutual parallelism in this application is not absolute parallelism. Approximate parallelism due to processing errors and assembly errors (e.g., the included angle between two structural features is 0.1°) is also within the scope of mutual parallelism in this application. This application does not impose specific limitations in this regard.

[0099] To facilitate understanding of the plan, some technical terms will be explained below:

[0100] Mechanical connection: Mechanical connection refers to the situation where two or more objects are connected or combined together by mechanical means. It is usually used for the connection of metals or other hard materials, such as bolts, screws, rivets, buckles, etc.

[0101] Metallurgical bonding: Metallurgical bonding is a method of fusing two metal surfaces at the atomic level through high-temperature melting or heat treatment processes. It usually involves the melting and recrystallization of materials to form a new metal structure.

[0102] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0103] This application provides an electronic device, which can be a terminal device with a casing, such as a mobile phone, laptop, tablet, television, or wearable smartwatch. This application does not impose any special limitations on the specific form of the electronic device. For ease of explanation and understanding, the structure and function of the electronic device are specifically described below using a mobile phone as an example. The mobile phone can be a non-folding phone or a folding phone; this application provides corresponding drawings and descriptions for both types of phones.

[0104] Please refer to Figures 1 to 4. Figure 1 is a three-dimensional structural diagram of the first embodiment of the electronic device of this application; Figure 2 is an exploded structural diagram of the first embodiment of the electronic device of this application; Figure 3a is a cross-sectional schematic diagram of the first embodiment of the electronic device of this application; Figure 3b is a cross-sectional schematic diagram of the first embodiment of the electronic device of this application; Figure 4 is a schematic diagram of the middle frame structure of the first embodiment of the electronic device of this application.

[0105] As shown in Figures 1 and 2, the electronic device 100 includes a housing 1. In one possible implementation, the electronic device 100 further includes a display screen 15 and a circuit board 14 mounted on the housing 1. The housing 1 serves to protect the electronic device and support the entire device, and has an internal accommodating space for housing the electronic components inside the electronic device 100. The display screen 15 and the circuit board 14 are disposed within the accommodating space of the housing 1.

[0106] The display screen 15 is used to display images. The display screen 15 may be, but is not limited to, an organic light-emitting diode (OLED) display screen, an active-matrix organic light-emitting diode (AMOLED) display screen, or a quantum dot light-emitting diode (QLED) display screen, etc. This application does not limit the type and specific structure of the display screen 5.

[0107] Circuit board 14 serves as a carrier for mounting and connecting electronic components in electronic device 100. For example, circuit board 14 may have multiple functional modules (not shown in the figure) to achieve corresponding functions, such as a charging management module, a power management module, a wireless communication module, an audio module, etc., which are not limited in this application. The type of circuit board 14 may be, for example, a PCB (Printed Circuit Board), an FPC (Flexible Printed Circuit), etc., which are not limited in this application.

[0108] In one possible implementation, the electronic device 100 further includes a battery assembly 13 installed within the housing 1. The battery assembly 13 is a functional device that supplies power to the various electronic components in the electronic device 100 and is typically connected to the circuit board 14. The battery assembly 13 may be, for example, a lithium-ion battery, a nickel-cadmium battery, a nickel-metal hydride battery, etc., and this application does not limit the specific type.

[0109] It should be noted that the accompanying drawings are for illustrative purposes only, and the size and positional relationship of the components in the drawings do not represent the size and positional relationship of the components in the actual product. The electronic device 100 may also include more or fewer components than those shown in the drawings, and this application does not impose any limitations on this.

[0110] Those skilled in the art will understand that the specific structure of the housing 1 is not limited. As shown in Figures 3a and 3b, in one possible implementation, the housing 1 includes a middle frame 11, which has a middle plate 112 and a frame 111. The frame 111 surrounds and connects to the outer periphery of the middle plate 112. The middle plate 112 supports the display screen 15 and the internal components of the electronic device 100. The frame 111 is a frame structure surrounding the outer periphery of the electronic device 100, and may include four sides surrounding the display screen 15 to help fix the display screen 15. In some possible implementations, the frame 111 may also include only three sides, two sides, etc., and this application does not limit this.

[0111] Furthermore, the electronic device 100 also includes a back cover 12, also known as a battery cover, which is located on the back of the electronic device 100. The back cover 12, the mid-frame 11, and the display screen 15 can together form a closed enclosure to house the electronic components inside the electronic device 100, while also protecting against dust, impacts, and hardware scratches. As shown in Figure 3a, in one possible implementation, the middle plate 112 of the mid-frame 11 is reused as the back cover 12. Specifically, in the thickness direction X of the electronic device, the display screen 15 is mounted on one side of the frame 111, and the middle plate 112 is connected to the other side of the frame 111 and serves as the back cover 12 of the electronic device 100. Alternatively, the entire mid-frame 11 can be understood as having a "U-shaped structure" in cross-section. With this structure, the middle plate 112 simultaneously performs the functions of both the middle plate 112 and the back cover 12, eliminating the need for an additional back cover 12, which helps save space and reduce the overall thickness and weight of the device. As shown in Figure 3b, in one possible implementation, the middle plate 112 can also be spaced apart from the rear cover 12, i.e., the rear cover 12 is provided separately. Specifically, in the thickness direction X of the electronic device, the middle plate 112 can be located in the middle of the frame 111, and the display screen 15 and the rear cover 12 are respectively mounted on both sides of the middle plate 112. With this structure, both the middle plate 112 and the rear cover 12 can be used to mount devices, providing more mounting space for electronic components.

[0112] As shown in Figure 4, in one possible implementation, the middle plate 112 has multiple areas, among which the area corresponding to the battery assembly 13 is the battery compartment area C. Understandably, different areas of the middle plate 112 are used to install different components, and different areas can be separated by structures such as stiffeners. This not only rationally divides the internal space of the electronic device 100, but also uses stiffeners and other structures to support and fix the components. Besides the battery compartment area C, the middle plate 112 can also have a circuit board area, a camera module area, a speaker area, etc., and this application does not impose any restrictions on this.

[0113] Those skilled in the art will understand that the mid-frame 11 needs to possess high strength and elastic modulus to protect electronic components and resist impacts and deformations during daily use. Generally, the overall mechanical performance and reliability of the mid-frame 11 can be improved by thickening the mid-plate 112. As the main power supply component of the electronic device 100, the battery module is usually large in size and occupies a large area on the mid-plate 112. Therefore, the battery compartment area C accounts for a large proportion of the area on the mid-plate 112, and the battery module is relatively fragile, posing a risk of expansion and fire upon impact. Therefore, the battery compartment area C needs to be thickened. However, with the trend towards miniaturization and thinning of the electronic device 100, the mid-plate 112 cannot be too thick, otherwise the entire device will be too bulky, affecting the user experience. Therefore, it is necessary to reduce the thickness of the mid-plate 112 as much as possible while ensuring strength. Furthermore, thinning the mid-plate 112 can provide more space for the battery, increasing battery capacity. In addition, considering the performance of the electronic device 100, the mid-plate 112 must also integrate multiple functions such as heat dissipation (high thermal conductivity), corrosion resistance, and high hardness and scratch resistance. In summary, to balance the reliability and slimness of the electronic device 100, the mid-plate 112 needs to be thinned as much as possible while maintaining structural strength, while also considering overall performance. This places extremely high demands on the material selection and manufacturing process of the mid-frame 11. Currently, the thinnest area C of the battery compartment of the mid-plate 112 can only reach 0.2mm, and further thinning is not possible. The following section will further illustrate this issue by examining several materials and processes used in the mid-frame 11.

[0114] Please refer to Figures 5 to 9. Figure 5 is a structural schematic diagram of the middle frame in the first reference design; Figure 6 is a structural schematic diagram of the middle frame in the second reference design; Figure 7 is a structural schematic diagram of the middle frame in the third reference design; Figure 8 is a structural schematic diagram of the middle frame in the fourth reference design; and Figure 9 is a schematic diagram of the mechanical bonding interface of friction stir welding.

[0115] As shown in Figure 5, in the first reference design, the mid-frame is made of a single piece of aluminum alloy, meaning both the mid-plate and the frame are integrally machined from aluminum alloy. Aluminum alloy is an alloy formed by adding a certain amount of other alloying elements to aluminum as the base material. It has the characteristics of being lightweight, high-strength, having good electrical and thermal conductivity, good corrosion resistance, and weldability, and is widely used in mobile phone casings. However, the strength and elastic modulus of a full-body aluminum alloy mid-frame are difficult to meet the requirements (the elastic modulus of aluminum alloy is only 68Gpa-72Gpa), and it is prone to large deformation under pressure and impact, which can squeeze the mobile phone display and cause it to break. In order to ensure the reliability of the aluminum alloy mid-frame, the thickness of the mid-plate is often increased to obtain higher strength and elastic modulus, especially in the battery compartment area, which accounts for a large proportion, making it impossible to truly thin the mid-plate.

[0116] In some designs, the entire mid-frame is made of stainless steel in a single piece. Stainless steel has sufficient strength and modulus of elasticity, but its density is approximately three times that of aluminum alloy (aluminum alloy has a density of 2.63 g / cm³). 3 ~2.85g / cm 3 Stainless steel has a density of up to 7.70 g / cm³. 3 ~8.00g / cm 3 This results in excessive weight for electronic devices. Furthermore, stainless steel surfaces are typically finished with PVD (Physical Vapor Deposition) coatings, which are easily scratched, affecting the aesthetics of the electronic devices.

[0117] As shown in Figure 6, in the second reference design, the middle plate is made of aluminum alloy, and the frame is made of titanium-aluminum layered composite material, which are welded together to form the shell. Titanium-aluminum layered composite material is a metal matrix composite (MMC) that combines titanium (Ti) and aluminum (Al) in a layered structure. This material combines the high strength, high temperature resistance, and corrosion resistance of titanium with the lightweight, high thermal conductivity, and good electrical conductivity of aluminum. Titanium-aluminum layered composite materials typically have higher strength, elastic modulus (the elastic modulus of titanium-aluminum layered composite materials can reach 110 GPa), and thermal stability than traditional aluminum alloys, resulting in superior overall performance. However, titanium and aluminum are two completely different materials with significantly different chemical properties. The process of fabricating them into a layered composite material is complex, and deformation during production can affect the dimensional yield of the middle frame. Furthermore, the bonding of titanium and aluminum is mostly mechanical, and brittle phases are easily generated in the bonding area, which can significantly compromise the reliability of the shell. Furthermore, the battery compartment area within the mid-plate is still made of aluminum alloy, making it impossible to balance strength with weight reduction and thinning in this area. On the other hand, the frame and mid-plate are connected by welding, resulting in high heat input, concentrated thermal stress, and easy deformation of the welded parts, reducing the yield and size of the mid-frame. In addition, the interface between the two materials is prone to uneven microstructure, making it susceptible to cracking.

[0118] As shown in Figure 7, in one reference design, the middle plate is made of aluminum alloy, and the frame is made of titanium-aluminum layered composite material. Unlike the scheme in Figure 6, the frame and middle plate are joined by friction stir welding (FSW). As shown in Figure 8, in another reference design, the frame is made of aluminum alloy, and the middle plate is made of composite material, which are joined by friction stir welding. Friction stir welding is a mechanical bonding process that uses a rotating stirring head to generate frictional heat at the interface of the two materials, causing them to melt and bond in a plastic state. Friction stir welding has high heat input and concentrated thermal stress, making it prone to deformation and reducing the yield and size of the middle frame. Furthermore, at the bonding surface of the friction stir weld, the two materials break down and mix, resulting in an uneven microstructure, making it difficult to form a high-density structure, reducing mechanical properties, lowering the overall reliability of the middle frame, and causing significant damage to the battery compartment area. As shown in Figure 9, in an example scenario, aluminum alloy and composite material are joined by friction stir welding. It can be seen that the bonding area of ​​the two materials has a high degree of breakage and an uneven microstructure, indicating that friction stir welding has a significant impact on the mechanical properties of the structural components.

[0119] In summary, the overall performance of the aforementioned shell is poor, making it difficult to meet diverse requirements such as strength and reliability, lightweight design, and thinning of the middle plate.

[0120] Based on this, the present application provides a housing and a method for manufacturing the housing, which can improve the overall mechanical properties of the housing, increase structural strength, and at the same time reduce the thickness of the middle plate, thereby achieving a lightweight and thin design of electronic devices or increasing battery capacity.

[0121] Please refer to Figures 10a to 11. Figure 10a is a schematic diagram of the shell structure of an embodiment of this application; Figure 10b is a schematic diagram of the shell structure of an embodiment of this application; Figure 10c is a schematic diagram of the shell structure of an embodiment of this application; Figure 11 is a schematic diagram of the metallurgical bonding interface of isostatic pressing sintering.

[0122] As shown in Figure 10a, the shell 200 includes a first part 201 and a second part 202, which are connected. The first part 201 is made of a metal alloy, and the second part 202 is made of a metal matrix composite material. The interface between the first part 201 and the second part 202 is a metallurgical bonding interface 203. The metal matrix of the metal alloy in the first part 201 is the same as the metal matrix of the metal matrix composite material in the second part 202, or the metal matrix of the metal alloy in the first part 201 and the metal matrix of the metal matrix composite material in the second part 202 are any two different types of materials: aluminum-based, titanium-based, and magnesium-based. The first part 201 constitutes the entire frame 111, and the second part 202 constitutes all areas of the middle plate 112. Alternatively, the first part 201 constitutes the entire frame 111 and a portion 112A of the middle plate 112, and the second part 202 constitutes another portion 112B of the middle plate 112 excluding the portion 112A.

[0123] The shell 200 provided in this application includes a first part 201 and a second part 202, which are made of different materials, making the material of the shell 200 more diversified. Materials can be selected specifically according to the position, area, and shape of the first part 201 and the second part 202 to meet the different structural material requirements of different parts of the shell 200 and improve the overall performance of the shell 200. Specifically, the entire frame of the shell 200 belongs to the first part 201, and the middle plate can belong entirely to the second part 202, or a portion can belong to the first part 201 and another portion 112B to the second part 202. That is, at least a portion of the frame 111 and the middle plate 112 are made of different materials. Since the frame 111 and the middle plate 112 are different parts of the housing 200, their material requirements also differ. For example, the housing 200 shown in Figures 10a to 10c is the middle frame 11. The frame 111 of the middle frame 11 serves as the external frame of the electronic device 100. In addition to considerations of strength and hardness, it is also required to have advantages such as wear resistance and ease of surface treatment to maintain a good tactile feel and appearance during use. The middle plate 112, as the supporting structure for the internal components of the device, needs to have sufficient strength and rigidity. Furthermore, the material selection should focus on characteristics such as heat dissipation performance, corrosion resistance, and light weight. Dividing the frame 111 and the middle plate 112 (at least a portion thereof) into the first part 201 and the second part 202 respectively can precisely meet their different material selection requirements.

[0124] Furthermore, the first part 201 is made of a metal alloy, and the second part 202 is made of a metal matrix composite material. Metal alloys have excellent comprehensive properties and come in a wide variety, which can meet the material selection requirements of the shell 200. Metal matrix composite materials are composite materials with metal or alloy as the matrix and fibers, whiskers, particles, etc. as reinforcements. They retain the properties of the metal itself and have the comprehensive properties of composite materials. Through the optimized combination of different matrices and reinforcements, composite materials with various special properties and excellent comprehensive properties can be designed to meet the material selection requirements of the middle plate 112. Metal alloys and metal composite materials themselves also have the advantages of being lightweight and high-strength, which can also benefit the weight reduction and thinning of the middle plate 112.

[0125] The interface between the first part 201 and the second part 202 is a metallurgical bonding interface 203, which can be understood as the first part 201 and the second part 202 being connected by a metallurgical bond. Compared with mechanical bonding, the mixing of the two materials at the bonding surface of a metallurgical bond is more uniform and smoother, resulting in a stronger bond and higher reliability. On the other hand, some metallurgical bonding technologies can be carried out under relatively uniform ambient temperatures, and can ensure that the shell 200 is heated evenly as a whole, avoiding stress concentration, reducing the deformation of the shell 200, and improving dimensional yield.

[0126] The metal alloy in Part 1 201 and the metal matrix composite material in Part 2 202 use the same metal matrix (for example, if Part 1 201 is an aluminum alloy, then Part 2 is an aluminum matrix composite material, and both materials are aluminum-based). The chemical properties of the two materials are relatively similar, resulting in more complete bonding and diffusion at the interface, and a stronger bond. Alternatively, the metal matrix of the metal alloy in Part 1 201 and the metal matrix composite material in Part 202 can be any two different types of aluminum-based, titanium-based, or magnesium-based materials. This can be understood as the two parts having different metal matrices, but both using aluminum-based, titanium-based, or magnesium-based materials (for example, if Part 1 201 is a titanium alloy, then Part 202 can be an aluminum matrix composite material, with the metal matrices of the two materials being titanium-based and aluminum-based, respectively). In this case, the chemical properties of the two metal matrices are relatively similar, and a good bonding effect can also be achieved.

[0127] As shown in Figure 11, exemplarily, aluminum alloy and aluminum-based composite material are bonded by isostatic pressing sintering (described in detail later), with the bonding interface between them being a metallurgical bonding interface 203. It can be seen that this bonding interface is relatively uniform, causes minimal damage to the material's microstructure, and exhibits no severe breakage or deformation in the bonding area, resulting in higher reliability.

[0128] As can be seen, the shell 200 provided in this application embodiment has strong comprehensive performance and can take into account diverse requirements such as reliable mechanical performance, lightweight, and thinning of the middle plate.

[0129] It should be noted that this application does not limit the specific areas of the first part 201 and the second part 202. As shown in Figure 10a, in one possible implementation, the first part 201 constitutes the entire frame 111, and the second part 202 constitutes all areas of the middle plate 112. That is, the entire frame 111 is made of metal alloy, and the entire middle plate 112 is made of metal-based composite material. This scheme has a relatively simple structure, which can simplify the subsequent lathe machining process. As shown in Figures 10b to 10c, in one possible implementation, a part constitutes the entire frame 111 and a portion of the middle plate 112, area 112A, and the second part 202 constitutes another portion of the middle plate 112, area 112B, excluding area 112A. It can be understood that the entire frame 111 is made of metal alloy, a portion of the middle plate 112 is made of metal alloy, and another portion, area 112B, is made of metal composite material. The portion of the middle plate 112 made of metal alloy can be machined together with the frame 111. This structure allows for different coatings and colors to be applied to the two areas of the middle plate 112, enriching the feel and appearance of the electronic device 100. The specific shapes of the two parts of the middle plate 112 are not limited; the dividing line between the two parts can be a straight line as shown in Figure 10a, or a curved line as shown in Figure 10b.

[0130] In one possible implementation, another portion 112B of the middle plate 112 includes the battery compartment region C of the middle plate 112. This can be understood as the battery compartment region C of the middle plate 112 being made of a metal-based composite material. While meeting the requirements of high strength and high elastic modulus, the thickness of the battery compartment region C can be reduced, reserving more installation space for the battery, thereby increasing battery capacity. In other possible implementations, the other portion 112B of the middle plate 112 may not cover the battery compartment region C; this application does not impose any restrictions on this.

[0131] Those skilled in the art will understand that the above description of the structure of the housing 200 is based on the middle frame 11 as an example. However, the housing 200 provided in this application is not limited to the middle frame 11, but may also be other housing structures in the electronic device 100. Examples are given below in conjunction with the accompanying drawings.

[0132] Please refer to Figures 12a to 13b. Figure 12a is a three-dimensional structural diagram of the second embodiment of the electronic device of the present application in the unfolded state; Figure 12b is a three-dimensional structural diagram of the second embodiment of the electronic device of the present application in the folded state; Figure 12c is a rear structural diagram of the second embodiment of the electronic device of the present application; Figure 13a is a structural diagram of the shaft cover in the second embodiment of the electronic device of the present application; Figure 13b is a cross-sectional structural diagram in the OO direction of Figure 13a.

[0133] As shown in Figures 12a to 12c, in one possible implementation, the electronic device 100 is a foldable electronic device, such as a foldable mobile phone. The foldable electronic device can be folded and unfolded to switch forms in different usage scenarios. It should be noted that the electronic device 100 can be a vertically foldable electronic device or a horizontally foldable electronic device; this application does not impose any limitation on this.

[0134] In one possible implementation, the electronic device 100 includes a housing assembly 2, which includes a first housing 21, a second housing 22, and a pivot mechanism 23. The first housing 21 and the second housing 22 are rotatably connected by the pivot mechanism 23, so that the electronic device 100 switches between a folded state and an unfolded state.

[0135] The electronic device 100 has a folded state and an unfolded state. For example, as shown in FIG12a, when the electronic device 100 is in the unfolded state, its opening angle is 180°, that is, the angle between the first housing 21 and the second housing 22 is 180°. Those skilled in the art will understand that the opening angle of the electronic device 100 can also be 90°, 120°, 210°, etc., and this application does not limit this. Furthermore, the angles illustrated in this application are allowed to have slight deviations. For example, when the electronic device 100 is in the unfolded state, its opening angle can be 180°, or it can be approximately 180°, such as 170°, 175°, 185°, or 190°. When the first housing 21 and the second housing 22 are stacked on top of each other, the electronic device 100 is in the closed state as shown in FIG12b, at which time the angle between the first housing 21 and the second housing 22 can be approximately considered to be 0°. In one possible implementation, the electronic device 100 is an inward-folding electronic device, where the housing assembly 2 completely surrounds the outside of the display screen 15 when the electronic device 100 is in the folded state. In some possible implementations, the electronic device 100 can also be an outward-folding electronic device, where the housing assembly 2 is located entirely inside the display screen 15 when folded.

[0136] In one possible implementation, the display screen 15 includes a first portion 151, a second portion 152, and a foldable portion 153. The first portion 151 is fixedly connected to the first housing 21, the second portion 152 is fixedly connected to the second housing 22, and the foldable portion 153 is located between the first portion 151 and the second portion 152, and is stacked with the pivot mechanism 23. During use, the first portion 151 and the second portion 152 remain in a planar state, while the foldable portion 153 can be bent to change the angle between the first portion 151 and the second portion 152, so that the display screen 15 folds or unfolds with the movement of the housing assembly 2. For example, the foldable portion 153 can be made of a flexible material to make it bendable.

[0137] It should be noted that the specific structures of the first housing 21 and the second housing 22 are not limited. In one possible implementation, both the first housing 21 and the second housing 22 may include a middle frame, which may include a side frame and a middle plate. Both the first housing 21 and the second housing 22 may also include a back cover, which may be provided separately or may be used in conjunction with the middle plate of the middle frame. It is understood that the middle frame 11 of the first housing 21 and the middle frame of the second housing 22 may adopt the structure of the housing 200 provided in the embodiments of this application to improve the mechanical and overall performance of any housing in the foldable electronic device 100, thereby achieving a thinner and lighter overall design for the foldable electronic device 100.

[0138] It should be noted that this application does not limit the specific structure of the hinge mechanism 23. As shown in Figures 12b to 13b, in one possible implementation, the hinge mechanism 23 includes a hinge cover 24. The hinge cover 24 is an exterior decorative component located on the outside of the electronic device 100, which can cover and protect the internal structure of the hinge mechanism 23. It is understood that the hinge mechanism 23 is the most frequently used mechanical component in the foldable electronic device 100. Its structure is complex, with many parts, and it is the core component for realizing the opening and closing function of the electronic device. If the hinge mechanism 23 is damaged, it will affect the overall use of the electronic device 100. Therefore, the hinge cover 24 needs to have sufficiently high strength to protect the internal structure of the hinge mechanism 23. On the other hand, the hinge cover 24 is a component of the appearance of the electronic device 100. When designing the structure and selecting materials for the hinge cover 24, the requirements for appearance processing must also be considered to make the electronic device 100 more aesthetically pleasing. In one possible implementation, the shaft cover 24 can also adopt the structure of the housing 200 provided in the embodiments of this application, which can not only ensure the structural strength and appearance processing performance of the shaft cover 24, but also reduce the thickness of the shaft cover 24 and reduce the weight of the electronic device 100.

[0139] As shown in Figures 13a and 13b, in one possible implementation, the shaft cover 24 includes a frame 241 and a middle plate 242, wherein the frame 241 is located on the outer periphery of the middle plate 242. The frame 241 may include four sides surrounding the outer periphery of the middle plate 242, or it may include only three sides, two sides, or one side; this application does not limit this, and the figures show two sides as an example. It is understood that providing the frame 241 around the middle plate 242 can better hide the internal structure of the pivot mechanism 23 inside the electronic device 100.

[0140] In one possible implementation, the first part 201 of the housing 200 constitutes the entire frame 241 of the shaft cover 24 and a portion 242A of the middle plate 242, while the second part 202 constitutes another portion 242B of the middle plate 242. Specifically, in the thickness direction Y of the pivot mechanism, a portion 242A and another portion 242B of the middle plate 242 are stacked. Alternatively, the frame 241 of the shaft cover 24 belongs to the first part 201 and is made of a metal alloy. The middle plate 242 of the shaft cover 24 is constructed using two layers of different materials: the layer outside the electronic device 100 belongs to the first part 201 of the housing 200 and is made of aluminum alloy, while the layer hidden inside the electronic device 100 belongs to the second part 202 of the housing 200 and is made of a metal-based composite material. With this structure, the second part 202 enhances the overall mechanical properties of the shaft cover 24. The first part 201, located on the outside of the electronic device 100, is made of a metal alloy that supports various surface treatments and processing techniques, such as anodizing, which can produce a beautiful and wear-resistant appearance. A metallurgical interface 203 connects the first part 201 and the second part 202, ensuring a strong bond, high reliability, and minimal processing deformation. Furthermore, the metal alloy and metal composite materials themselves possess the advantages of being lightweight and high-strength, reducing the thickness and weight of the shaft cover 24 and contributing to the slimming and lightening of the electronic device 100.

[0141] It should be noted that the division of the first part 201 and the second part 202 in the shaft cover 24 is also the same as the above scheme. In addition to the middle frame 11 and the shaft cover 24, other housings in the electronic device 100 are also applicable to the structure of the housing 200 provided in this application, and will not be listed one by one in this application.

[0142] It should be noted that this application does not limit the specific materials of the first part 201 and the second part 202. In one possible implementation, the material of the first part 201 is one of aluminum alloy, titanium alloy, and magnesium alloy, and the material of the second part 202 is one of aluminum matrix composite (AMMC), titanium matrix composite, and magnesium matrix composite. For example, when the first part 201 is aluminum alloy, the second part 202 is aluminum matrix composite. When the first part 201 is titanium alloy, the second part 202 is titanium matrix composite or aluminum matrix composite. When the first part 201 is magnesium alloy, the second part 202 is magnesium matrix composite. Those skilled in the art will understand that alloys and composites of metal elements such as aluminum, titanium, and magnesium have the advantages of low density, high modulus, high strength, and high thermal conductivity. Selecting these materials is beneficial for achieving overall thinness, reliability, and compatibility of heat dissipation performance in the casing 200.

[0143] In one possible implementation, the first part 201 is made of aluminum alloy, and the second part 202 is made of aluminum-based composite material. Aluminum alloy is an alloy formed by adding a certain amount of other alloying elements to pure aluminum as the base material. It possesses lightweight, high strength, and good electrical and thermal conductivity. Aluminum-based composite material is a composite material formed by dispersing one or more reinforcing materials in an aluminum alloy matrix. It inherits the advantages of aluminum alloy while utilizing the characteristics of the reinforcing elements, exhibiting higher specific strength, specific stiffness, wear resistance, fatigue resistance, and a low coefficient of thermal expansion. During the production of aluminum-based materials, different properties can be obtained by adjusting the chemical composition and processing technology. For example, by adding alloying elements such as magnesium, silicon, copper, manganese, and zinc, different series of aluminum alloys can be produced, such as:

[0144] 1-series aluminum alloys, made of pure aluminum, have the highest electrical and thermal conductivity.

[0145] 2-series aluminum alloys, with copper as the main alloying element, have good strength and hardness.

[0146] 3-series aluminum alloys, with manganese as the main alloying element, have good rust resistance.

[0147] 5-series aluminum alloys, with magnesium as the main alloying element, have good corrosion resistance and weldability.

[0148] 6-series aluminum alloys, with magnesium and silicon as the main alloying elements, have high strength and good machinability.

[0149] 7-series aluminum alloys, with zinc as the main alloying element, are ultra-hard aluminum alloys with extremely high strength.

[0150] Each series of aluminum alloys has different grades. For example, 6061 is a common grade of 6-series aluminum alloys. Its main components are 1% magnesium and 0.6% silicon. After T6 heat treatment, it has high strength.

[0151] In one possible implementation, the first part 201 can be made of 3-series aluminum alloy, and the substrate of the aluminum-based composite material in the second part 202 can be a 2-series or 3-series aluminum alloy. Alternatively, the first part 201 can be made of 6-series aluminum alloy, and the substrate of the aluminum-based composite material in the second part 202 can be a 5-series, 6-series, or 7-series aluminum alloy. Alternatively, the first part 201 can be made of 7-series aluminum alloy, and the substrate of the aluminum-based composite material in the second part 202 can be a 6-series or 7-series aluminum alloy. Alternatively, the first part 201 can be made of titanium alloy, and the substrate of the aluminum-based composite material in the second part 202 can be a 5-series, 6-series, or 7-series aluminum alloy.

[0152] This can be understood as follows: the materials of the first part 201 and the second part 202 are the same or similar, resulting in more thorough and uniform mixing of the microparticles of the two materials at the metallurgical interface, further improving reliability. Furthermore, similar aluminum-based materials require similar processing temperatures in heat treatment and other processes, leading to better matching and reducing the difficulty of manufacturing the shell 200. For example, if the first part 201 is made of 6-series aluminum alloys (such as 6013, 3003, 6061, 6063, etc.), the substrate of the aluminum-based composite material in the second part 202 is preferably a 6-series or 7-series aluminum alloy (such as 6013, 3003, 6061, 6063, 7003, 7055, 7034, etc.). Alternatively, if the first part 201 is made of 7-series aluminum alloys, the substrate of the aluminum-based composite material in the second part 202 is preferably a 6-series or 7-series aluminum alloy. In this case, a better match can be achieved when the heat treatment temperature of the aluminum-based composite material in the second part 202 is close to or lower than the temperature of the aluminum substrate in the first part 201. It should be noted that if there are no special requirements for the performance of the shell material 200 and the bonding force between the first part 201 and the second part 202, aluminum alloys of various series can be matched with each other. For example, when the first part 201 is a 2-series or 3-series aluminum alloy (such as 2024, 3003, etc.), the second part 202 can also be a 5-series (such as 5052, 5083, etc.), 6-series, 7-series aluminum alloy, etc. This application does not impose any restrictions on this.

[0153] In one possible implementation, the first part 201 is made of titanium alloy, and the second part 202 is made of aluminum-based composite material. Titanium alloy is an alloy formed by adding a certain amount of other alloying elements to titanium as the base material, and has advantages such as low density, high strength, and corrosion resistance. This application does not limit the specific type of titanium alloy, such as TA (α-type titanium alloy and α-type titanium alloy), TB (β-type titanium alloy and near-β-type titanium alloy), or TC (α+β-type titanium alloy). In one possible implementation, the first part 201 is made of TC-type titanium alloy, specifically TC4, TC6, TC9, TC10, TC11, etc., which can be selected as needed. When the first part 201 is made of titanium alloy, the specific type of aluminum-based composite material in the second part 202 is not limited. In one possible implementation, the base material of the aluminum-based composite material in the second part is a 6-series or 7-series aluminum alloy to achieve chemical properties that are similar to those of titanium alloys. The micro-particles of the two materials are more thoroughly mixed at the metallurgical interface, resulting in higher reliability. Furthermore, they can be better matched in processing techniques such as heat treatment, reducing processing difficulty.

[0154] In one possible implementation, the material of part 202 is either a fiber-reinforced metal matrix composite or a particle-reinforced metal matrix composite. By adding reinforcements to the metal matrix composite, specific properties can be optimized while maintaining the original material characteristics. Fiber-reinforced metal matrix composites are metal matrix composites with fibers as reinforcements, such as carbon fiber, glass fiber, boron fiber, etc., with no specific limitations. Fiber-reinforced metal matrix composites are lightweight, high-strength, and possess high stiffness and thermal stability. By changing the fiber type, arrangement, and matrix material, the properties of the composite material can be customized to meet different application requirements. Particle-reinforced metal matrix composites are metal matrix composites with particles as reinforcements, such as one, two, or three of the following: SiC (silicon carbide), Al2O3 (alumina), B4C (boron carbide), TiB2 (titanium boron carbide), graphene, carbon nanotubes, graphite, and diamond. Particle-reinforced metal matrix composites have good wear resistance, can improve the thermal expansion properties of the material, and help reduce thermal stress during processing. It should be noted that Part 202 can also be other types of metal matrix composites, such as fabric-reinforced metal matrix composites, whisker-reinforced metal matrix composites, etc., or SiC and graphene composites, SiC and Al2O3 composites, etc., which will not be listed in this application.

[0155] In one possible implementation, the material of part 202 is an aluminum-based composite material with SiC as reinforcing particles, wherein SiC particles with a diameter of 0-0.2 μm are dispersed in the aluminum alloy substrate at a volume fraction of 0-5%. Alternatively, SiC particles with a diameter of 0.5 μm-1 μm are dispersed in the aluminum alloy substrate at a volume fraction of 0-10%. Alternatively, SiC particles with a diameter of 3 μm-20 μm are dispersed in the aluminum alloy substrate at a volume fraction of 8-25%. Other dispersion ratios of SiC particles are also possible, such as SiC particles with a diameter of 0-0.2 μm being dispersed in the aluminum alloy substrate at a volume fraction greater than 5%, SiC particles with a diameter of 0.5 μm-1 μm being dispersed in the aluminum alloy substrate at a volume fraction greater than 10%, and SiC particles with a diameter of 3 μm-20 μm being dispersed in the aluminum alloy substrate at a volume fraction less than 8% or greater than 25%, etc. This application does not limit this; the specific ratio selected should be determined according to actual needs and production conditions.

[0156] In one possible implementation, the housing 200 further includes an anodized layer 204, which is applied to the outer surface of the first portion 201. This can be understood as an anodizing process being used to treat the surface of the housing 200. Anodizing is a surface treatment technology used for aluminum and aluminum alloys, which forms a protective and decorative oxide film, namely the anodized layer 204, on the metal surface through an electrochemical method. The anodized layer 204 provides a beautiful appearance on the surface of the first portion 201 and is resistant to discoloration, wear, and corrosion, does not easily peel off, and has good heat dissipation performance. In some possible implementations, the surface of the first portion 201 may not have an anodized layer 204, or other types of films may be used, such as PVD films, sandblasted layers, etc., which this application does not limit.

[0157] The interface between the first part 201 and the second part 202 is a metallurgical bonding interface 203, and the specific method of metallurgical bonding is not limited. As shown in Figure 11, in one possible implementation, the first part 201 and the second part 202 are connected by isostatic pressing sintering. Isostatic pressing is a sintering technique carried out in a high-temperature and high-pressure gas environment. Isostatic pressing refers to achieving the shaping or enhancing the density of a material by applying equal pressure in all directions. It can promote the densification of the material and improve its density and uniformity. During isostatic pressing sintering, the first part 201 and the second part 202 are uniformly subjected to pressure and heat, and the expansion and contraction are consistent throughout, which can avoid cracking and result in small deformation of the blank, leading to a higher dimensional yield of the shell 200. Compared with welding, friction stir welding, and other techniques, isostatic pressing sintering can achieve material densification, which helps to protect the microstructure and properties of the material. In addition to isostatic pressing sintering, the first part 201 and the second part 202 can also be combined by conventional sintering techniques, and this application does not limit this.

[0158] The method for manufacturing the shell 200 provided in this application embodiment involves connecting the first part 201 and the second part 202 of the shell 200 using isostatic pressing sintering technology. This improves the overall performance of the shell 200, particularly its strength and modulus of elasticity. Combining isostatic pressing sintering with the selection of materials for the first part 201 and the second part 202 allows for the manufacture of a shell 200 with excellent mechanical properties, high reliability, good heat dissipation, and a slim profile.

[0159] Please refer to Figures 14a to 15. Figure 14a is a flowchart of the preparation method of the shell according to an embodiment of this application; Figure 14b is a schematic diagram of the steps of the preparation method of the shell according to an embodiment of this application, wherein the shell is a middle frame; Figure 14c is a schematic diagram of the steps of the preparation method of the shell according to an embodiment of this application, wherein the shell is a shaft cover; Figure 15 is a flowchart of the preparation method of the shell according to an embodiment of this application.

[0160] As shown in Figures 14a to 14c, the method for preparing the shell includes:

[0161] Step S1: Provide a first preform 3; wherein the first preform 3 has a filling space 31, and the material of the first preform 3 is a metal alloy.

[0162] Step S2: Fill the filling space 31 of the first preform 3 with metal matrix composite powder 32. The first preform 3 includes an annular frame preform, with the frame preform surrounding the hollowed-out filling space 31; or, the first preform 3 includes an annular frame preform and a first middle plate preform adjacent to the inner periphery of the frame preform, with the frame preform and the first middle plate preform surrounding the filling space 31.

[0163] Step S3: The first preform 3 filled with metal matrix composite powder 32 is subjected to isostatic pressing sintering to obtain the shell preform 4. The shell preform 4 includes the first preform 3 after isostatic pressing sintering and the second preform 5 formed of metal matrix composite powder 32. The first preform 3 and the second preform 5 are connected, and the interface is a metallurgical bonding interface 203.

[0164] Step S4: The shell 200 is obtained by processing the shell preform 4. The first part 201 of the shell 200 is obtained by the first part preform 3 of the shell preform 4, and the second part 202 of the shell 200 is obtained by the second part preform 5 of the shell preform 4.

[0165] This can be understood as follows: the first preform 3 is used to fabricate the first part 201 of the shell 200. Powdered metal-based composite material is filled into the filling space 31 of the first preform 3, and after isostatic pressing and sintering, the shell preform 4 is formed. The powdered metal-based composite material, after sintering, forms a solid second preform 5, which is bonded to the sintered first preform 3. The interface between the first preform 3 and the second preform 5 is a metallurgical bonding interface 203. Finally, the shell preform 4 is machined into the shell 200, for example, by turning it on a lathe.

[0166] Those skilled in the art will understand that in step S1, the first preform 3 is in solid form, allowing powder to be filled into its filling space 31. This application does not limit the specific formation method of the first preform 3. In one possible implementation, the first preform 3 is obtained by cutting a metal alloy profile. In another possible implementation, the first preform 3 may also be formed by sintering powdered material, solidifying liquid material, or forging block material, etc., which will not be listed here. The filling space 31 on the first preform 3 can be hollow (when machining the middle frame 11) or a groove-shaped space with a bottom (such as when machining the shaft cover 24), which is not limited here.

[0167] In one possible implementation, in step S2, the metal matrix composite powder 32 completely fills the filling space 31. Alternatively, the metal matrix composite powder 32 may not completely fill the filling space 31, for example, only filling half of it; this application does not limit this.

[0168] As shown in Figure 15, in one possible implementation, step S2, the preparation of the filled metal matrix composite powder 32, includes:

[0169] Step S021: Pre-treat and surface modify the reinforcing preform powder to obtain the reinforcing powder.

[0170] Step S022: Mix the reinforcing material powder with the base material powder containing the metal matrix to obtain metal matrix composite powder 32.

[0171] Among them, the reinforcing preform powder is such as SiC powder, Al2O3 powder, etc., and the metal-based substrate powder is such as aluminum alloy powder, titanium alloy powder, etc. In step S022, the two powders are mixed in a specific ratio, for example, SiC powder with a particle diameter of 0-0.2μm is dispersed in aluminum alloy substrate powder at a volume fraction of 0-5%.

[0172] In step S021, surface modification treatment alters the surface properties of the material through physical, chemical, or mechanical methods to meet specific application requirements. This can improve the dispersion of the reinforcing preform powder in the metal substrate powder and enhance their wettability. For example, the pretreatment and surface modification process may include sequentially performing pretreatments such as acid washing, sensitization, and activation on the reinforcing preform powder, followed by modification treatments such as electroless copper plating and nickel plating to obtain the reinforcing material powder. In step S022, the reinforcing material powder can be mixed with the metal-based substrate powder using an instrument such as a ball mill to achieve a mixed powder with no segregation and no agglomeration.

[0173] It should be noted that the preparation of metal matrix composite powder 32, the pretreatment and surface modification of reinforcing preform powder, and the mixing of the two powders may include more or fewer steps than described above in actual production, and this application does not limit them.

[0174] Please refer to Figures 16a to 17b. Figure 16a is a flowchart of the preparation method of the shell in the embodiment of this application (Figure 3); Figures 16b-16c are schematic diagrams of the isostatic pressing sintering steps in the preparation method of the shell in the embodiment of this application (Figure 16b-16c); Figure 17a is a flowchart of the preparation method of the shell in the embodiment of this application (Figure 17a-17b); Figure 17b is a schematic diagram of the heat treatment steps in the preparation method of the shell in the embodiment of this application (Figure 17b-17b).

[0175] As shown in Figures 16a and 16b, in one possible implementation, step S3, which involves isostatically pressing the first preform 3 filled with metal matrix composite powder 32 to obtain the shell preform 4, includes:

[0176] Step S31: The first part of the preform 3 filled with metal matrix composite powder 32 is cold isostatically pressed to form a cold-pressed preform 61.

[0177] Step S32: Place the cold-pressed blank 61 into the hot-pressing mold 62.

[0178] Step S33: Vacuum degassing and sealing of the hot pressing mold 62 on which the cold-pressed blank 61 is placed.

[0179] Step S34: The hot pressing mold 62, which has been degassed under vacuum and contains the cold-pressed blank 61, is subjected to hot isostatic pressing sintering to form a combination of the hot pressing mold 62 and the hot-pressed blank 63.

[0180] Step S35: By processing the combination of hot pressing mold 62 and hot pressing blank 63, the hot pressing mold 62 is removed to obtain hot pressing blank 63.

[0181] Step S36: Heat-treat the hot-pressed blank 63 to obtain the shell preform 4.

[0182] Cold isostatic pressing (CIP) refers to placing powder (metal matrix composite powder 32) in a flexible mold at room temperature, and then applying isotropic pressure through a liquid transfer medium such as oil or paraffin to form a cold-pressed preform 61. Performing CIP on the first preform 3 filled with metal matrix composite powder 32 before hot isostatic pressing (i.e., step S31) can improve the forming density, structural uniformity, and dimensional accuracy of the hot-pressed preform 63, eliminate porosity, and optimize the sintering effect. CIP is usually performed at room temperature. In one possible implementation, the CIP pressure is between 3 MPa and 15 MPa, and the holding time is between 5 min and 45 min. It should be noted that the CIP pressure can also be less than 3 MPa or greater than 15 MPa, and the holding time can be less than 5 min or greater than 45 min; this application does not impose any limitations on this. CIP can be performed, for example, in a hydraulic press; this application does not impose any limitations on this either.

[0183] Before hot isostatic pressing (HIP) sintering, the cold-pressed blank 61 needs to be placed in a hot pressing mold 62 and subjected to vacuum degassing and sealing (i.e., steps S32 and S33 above). The hot pressing mold 62, also called a sheath, provides support and constraint for the blank, preventing deformation during HIP sintering. The sheath also limits the volume expansion of the blank during sintering, thus promoting material densification. The material of the hot pressing mold 62 is not limited; in one possible implementation, the sheath can be made of a relatively soft metal alloy, such as an aluminum alloy with a high aluminum content.

[0184] Furthermore, the hot-pressing mold 62, on which the cold-pressed preform 61 is placed, is subjected to vacuum degassing and then sealed. Vacuum degassing removes air from the hot-pressing mold 62, reducing oxidation and other chemical reactions that may occur during sintering, thus protecting the preform from oxidation or contamination. It also prevents the formation of bubbles inside the material at high temperatures, which could affect sintering quality and material density. Exemplarily, the vacuum degassing steps may include loading (placing the material or workpiece to be degassed into the vacuum furnace), vacuuming (closing the furnace door, starting the vacuum pump, and extracting air and other gases from the furnace to create a low-pressure environment), heating (heating the material in a vacuum environment; heat can promote the release of gases inside the material), gas release (under the combined action of heating and vacuum, the gases inside the material are gradually released and extracted by the vacuum pump), holding time (maintaining at a certain temperature and vacuum level for a period of time to ensure that the gases inside the material are fully discharged), cooling, unloading, etc., which are not limited in this application.

[0185] Step S34 above is hot isostatic pressing (HIP), which involves solidifying the powder in a high-temperature and high-pressure gas environment. During HIP, the temperature and pressure applied to the hot pressing mold 62 in all directions are consistent. The combination of high temperature and high pressure promotes the diffusion process within the material, helps fill pores, achieves high-density or near-completely dense sintering, and reduces internal porosity, improving grain growth and resulting in a uniform microstructure. Therefore, the hot-pressed preform 63 formed by HIP can achieve material densification, and the interface between the metal alloy and the metal matrix composite is uniform, exhibiting excellent mechanical and physical properties. In one possible implementation, the HIP sintering temperature is 580℃-620℃, the pressure is 5MPa-30MPa, and the holding time is 10min-60min. It should be noted that the temperature of hot isostatic pressing (HIP) sintering can be less than 580℃ or greater than 620℃, the pressure can be less than 5 MPa or greater than 30 MPa, and the holding time can be less than 10 min or greater than 60 min; this application does not impose any restrictions on these. For example, HIP sintering can be carried out in a hot press furnace using a metal (such as molybdenum wire) as the resistance heating element; this application does not impose any restrictions on this.

[0186] As shown in Figure 16c, in one possible implementation, multiple cold-pressed blanks 61 can be stacked and placed together in a hot-pressing mold 62 for sintering, thereby improving production efficiency. To prevent the blanks from sintering together, adjacent cold-pressed blanks 61 can be separated by a lubricating medium such as graphite paper 64, facilitating subsequent demolding. The thickness of the graphite paper 64 can be, for example, 0.3 mm to 1 mm, and this application does not limit this.

[0187] Those skilled in the art will understand that the hot pressing mold 62 and the blank can be sintered together by hot isostatic pressing, forming a combination of the hot pressing mold 62 and the hot pressing blank 63. The hot pressing mold 62 needs to be removed subsequently, i.e., step S35. The hot pressing mold 62 can be removed by machine tool processing or other methods, and this application does not impose any restrictions on this.

[0188] Step S36 involves heat treatment of the hot-pressed blank 63 to further improve its performance. Heat treatment refers to altering the internal structure and properties of a material by heating it to a certain temperature and holding it for a period of time, followed by cooling it at a specific rate. Specific processes include annealing, normalizing, quenching, tempering, surface hardening, carburizing, solution treatment, aging treatment, forging heat treatment, etc. This application does not limit the scope of these processes.

[0189] As shown in Figures 17a and 17b, in one possible implementation, the step of heat-treating the hot-pressed blank 63 to obtain the shell preform 4 in step S35 includes:

[0190] Step S361: The hot-pressed preform 63 is subjected to solution treatment at a temperature of 450℃-500℃ for 1h-4h.

[0191] Step S362: The hot-pressed blank 63 after solution treatment is quenched in cold water.

[0192] Step S363: The hot-pressed blank 63 after cold water quenching is subjected to artificial aging treatment at a temperature of 120℃-180℃ for 2h-24h to obtain the shell preform 4.

[0193] Solution treatment, also known as dissolution treatment or homogenization treatment, can improve the microstructure and macroscopic properties of metallic materials, enhancing their toughness and strength. The main steps of solution treatment include heating and holding. Heating refers to heating the blank to a specific temperature (e.g., 450℃-500℃), typically above the alloy's solution line, allowing the second phase or solute atoms in the alloy to dissolve into the base metal. In some possible implementations, the heating temperature for solution treatment can be less than 450℃ or greater than 500℃; this application does not impose any limitations on this. Holding refers to maintaining the blank at the solution temperature for a period of time (e.g., 1h-4h) after reaching the solution temperature to ensure that the solute atoms fully dissolve into the solvent metal, achieving a uniform distribution. In some possible implementations, the holding time for solution treatment can be less than 1h or greater than 4h; this application does not impose any limitations on this.

[0194] Cold water quenching refers to the process of rapidly cooling a blank after solution treatment by immersing it in cold water. The temperature of the cold water is usually around room temperature, but ice water can also be used for an even faster cooling rate. The purpose of rapidly cooling the blank is to suppress the precipitation of the second phase during the cooling process, ensuring maximum supersaturation of solute atoms and vacancies, so that the highest strength and best corrosion resistance can be obtained after subsequent artificial aging treatment.

[0195] Artificial aging treatment, also known as artificial aging process or incomplete quenching, can improve the hardness and strength of non-ferrous metals such as aluminum alloys. By holding the material at a relatively low temperature for an extended period, the supersaturated solid solution inside the material decomposes, generating fine and uniformly distributed second-phase particles, thereby enhancing the material's mechanical properties. The holding time can be 2-4 hours, or less than 2 hours or more than 4 hours; this application does not impose any limitations on this. In some possible implementations, the temperature of the artificial aging treatment can also be less than 120°C or greater than 180°C; this application does not impose any limitations on this either.

[0196] It should be noted that isostatic pressing sintering of the first preform 3 filled with metal matrix composite powder 32 may include more or fewer steps than described above, and this application does not limit this.

[0197] Please refer to Figure 18, which is a flowchart of the shell preparation method according to an embodiment of this application.

[0198] As shown in Figure 18, in one possible implementation, the step S4 above, which involves processing the shell preform 4 to obtain the shell 200, includes:

[0199] Step S41: The first preform 3 connected to the second preform 5 is sequentially subjected to one CNC machining, T treatment, nano injection molding, two CNC machining, grinding and polishing, sandblasting and anodizing to obtain the shell 200.

[0200] Among them, numerical control machining, such as CNC (Computer Numerical Control), refers to automated machining technology controlled by a computer, which can achieve high-precision and high-efficiency machining and can produce complex shapes. T-processing can be understood as heat treatment, which can further improve the physical and chemical properties of the housing 200. Secondary CNC machining can further improve the machining accuracy of the housing 200. Grinding, polishing, sandblasting, anodizing, and other steps are used to process the surface of the housing 200, forming rich colors and appearances. The processing of the housing preform 4 can also include more or fewer steps; this application does not limit this.

[0201] The following examples illustrate the specific steps in preparing the shell 200 using several different material selections.

[0202] Please refer to Figures 19 to 23. Figure 19 is a flowchart of the preparation method of the shell according to an embodiment of this application (Sixth); Figure 20 is a flowchart of the preparation method of the shell according to an embodiment of this application (Seventh); Figure 21 is a flowchart of the preparation method of the shell according to an embodiment of this application (Eighth); Figure 22 is a flowchart of the preparation method of the shell according to an embodiment of this application (Nineth); and Figure 23 is a flowchart of the preparation method of the shell according to an embodiment of this application (Tenth).

[0203] As shown in Figure 19, in one possible implementation, the method for preparing the shell 200 includes the following steps:

[0204] Step L021: Pre-treat and surface modify the SiC powder to obtain the reinforcing material powder.

[0205] Step L022: Mix SiC powder with 7075 aluminum alloy powder (D50≤20 micrometers) to obtain aluminum-based composite material powder.

[0206] Step L1: Provide a first preform 3; wherein the first preform 3 has a filling space 31, and the material of the first part 201 is 6013 aluminum alloy.

[0207] Step L2: Fill the 6013 aluminum alloy filling space 31 with aluminum-based composite powder.

[0208] Step L31: The 6013 aluminum alloy profile blank filled with aluminum-based composite material powder is cold-pressed under a hydraulic press at a pressure of 10 MPa for 30 minutes to form a cold-pressed blank 61.

[0209] Step L32: Stack multiple cold-pressed blanks 61 in a hot-pressing mold 62, and use graphite paper 64 with a thickness of 0.6 mm as a lubricating medium between adjacent cold-pressed blanks 61.

[0210] Step L33: Vacuum degassing and sealing of the hot pressing mold 62 on which the cold-pressed blank 61 is placed.

[0211] Step L34: The hot pressing mold 62, which has been degassed under vacuum and contains the cold-pressed blank 61, is subjected to hot isostatic pressing to form a combination of the hot pressing mold 62 and the hot-pressed blank 63. The sintering temperature is 590 degrees Celsius, the pressure is 25 MPa, and the holding time is 40 min.

[0212] Step L35: By processing the combination of hot pressing mold 62 and hot pressing blank 63, the hot pressing mold 62 is removed to obtain the hot pressing blank 63.

[0213] Step L361: The hot-pressed preform 63 is subjected to solution treatment at 470℃ for 1 hour.

[0214] Step L362: The hot-pressed blank 63 after solution treatment is quenched in cold water.

[0215] Step L363: The hot-pressed blank 63 after cold water quenching is subjected to artificial aging treatment at 120°C for 24 hours to obtain the shell preform 4.

[0216] Step L41: The shell preform 4 is machined by CNC to obtain the shell 200.

[0217] Steps L021 and L022 can be performed before step L1 or between step L1 and L2, and this application restricts each other accordingly. In step L022, if nanoscale SiC powder (D50 of 50 nm, where D50 represents the particle size corresponding to a cumulative particle size distribution percentage of 50% in a sample, also known as the median particle size or median particle size) is used, its volume fraction in the aluminum alloy substrate is 5%. If submicron-sized SiC powder (D50 of 15 μm) is used, its volume fraction in the aluminum alloy substrate is 18%. Powder mixing can be carried out in a ball mill, and the elastic modulus of the mixed aluminum-based composite material is approximately 110 GPa. In step L1, the first preform 3 can be a hollow cuboid-shaped mobile phone frame formed by cutting profiles, with a thickness of 10 mm. In step L34, hot isostatic pressing sintering can be carried out in a hot press furnace using metal wire as the resistance heating wire.

[0218] The shell 200 prepared using the above steps exhibits minimal sintering deformation and high dimensional yield. The bonding surface between the aluminum alloy profile and the aluminum-based composite material is a metallurgical bonding interface 203, ensuring highly reliable strength. Compared to existing technologies, the modulus of the entire shell 200 is increased by 50%, from approximately 70 GPa to over 100 GPa, and the thermal conductivity is also improved from below 120 W / m·K to over 150 W / m·K.

[0219] As shown in Figure 20, in one possible implementation, the method for preparing the shell 200 includes the following steps:

[0220] Step M021: Pre-treat and surface modify the SiC powder to obtain the reinforcing material powder.

[0221] Step M022: Mix SiC powder with 7055 aluminum alloy powder (D50≤20 micrometers) to obtain aluminum-based composite material powder.

[0222] Step M1: Provide a first preform 3; wherein the first preform 3 has a filling space 31, and the material of the first part 201 is 6063 aluminum alloy.

[0223] Step M2: Fill the 6063 aluminum alloy filling space 31 with aluminum-based composite material powder.

[0224] Step M31: The 6063 aluminum alloy profile blank filled with aluminum-based composite material powder is cold-pressed under a hydraulic press at a pressure of 11 MPa for 25 minutes to form a cold-pressed blank 61.

[0225] Step M32: Stack multiple cold-pressed blanks 61 in a hot-pressing mold 62, and use graphite paper 64 with a thickness of 0.7 mm as a lubricating medium between adjacent cold-pressed blanks 61.

[0226] Step M33: Vacuum degassing and sealing of the hot pressing mold 62 on which the cold-pressed blank 61 is placed.

[0227] Step M34: The hot pressing mold 62, which has been degassed under vacuum and contains the cold-pressed blank 61, is subjected to hot isostatic pressing to form a combination of the hot pressing mold 62 and the hot-pressed blank 63. The sintering temperature is 580 degrees Celsius, the pressure is 25 MPa, and the holding time is 50 min.

[0228] Step M35: By processing the combination of hot pressing mold 62 and hot pressing blank 63, the hot pressing mold 62 is removed to obtain the hot pressing blank 63.

[0229] Step M361: The hot-pressed preform 63 is subjected to solution treatment at a temperature of 460℃ for 2 hours.

[0230] Step M362: The hot-pressed blank 63 after solution treatment is quenched in cold water.

[0231] M363: The hot-pressed blank 63, which has been quenched in cold water, is subjected to artificial aging treatment at 140℃ for 18 hours to obtain the shell preform 4.

[0232] Step M41: The shell preform 4 is machined by CNC to obtain the shell 200.

[0233] In this application, steps M021 and M022 can be performed before step M1 or between step M1 and step M2, and this application does not impose any restrictions on this. In step M022, if nanoscale SiC powder (D50 of 20 nm) is used, its volume fraction in the aluminum alloy substrate is 3%. If submicron-scale SiC powder (D50 of 20 μm) is used, its volume fraction in the aluminum alloy substrate is 19%. Powder mixing can be carried out in a ball mill, and the elastic modulus of the mixed aluminum-based composite material is approximately 105 GPa. In step M1, the first preform 3 can be a hollow cuboid-shaped mobile phone frame formed by cutting profiles, with a thickness of 10 mm. In step M34, hot isostatic pressing sintering can be carried out in a hot press furnace using metal wire as the resistance heating element.

[0234] The casing 200 prepared using the above steps exhibits minimal sintering deformation and high dimensional yield. The bonding surface between the aluminum alloy profile and the aluminum-based composite material is a metallurgical bonding interface 203, ensuring highly reliable strength. Compared to existing technologies, the modulus of the entire casing 200 is increased by 50%, from approximately 70 GPa to over 100 GPa, and the thermal conductivity is also improved from below 120 W / m·K to over 150 W / m·K. Currently, the thinnest plate 112 (battery compartment area C) in the industry's mobile phone casing 200 is 0.2 mm. The casing 200 prepared using the above method can be further thinned to 0.15 mm, increasing the battery capacity by 100 mA while maintaining a fixed mobile phone thickness.

[0235] As shown in Figure 21, in one possible implementation, the method for preparing the shell 200 includes the following steps:

[0236] Step N021: Pre-treat and surface modify the SiC powder to obtain the reinforcing material powder.

[0237] Step N022: Mix SiC powder with 7034 aluminum alloy powder (D50≤20 micrometers) to obtain aluminum-based composite material powder.

[0238] Step N1: Provide a first preform 3; wherein the first preform 3 has a filling space 31, and the material of the first part 201 is 6063 aluminum alloy.

[0239] Step N2: Fill the 6013 aluminum alloy filling space 31 with aluminum-based composite powder.

[0240] Step N31: The 6013 aluminum alloy profile blank filled with aluminum-based composite material powder is cold-pressed under a hydraulic press at a pressure of 10 MPa for 30 minutes to form a cold-pressed blank 61.

[0241] Step N32: Stack multiple cold-pressed blanks 61 in a hot-pressing mold 62, and use graphite paper 64 with a thickness of 0.5 mm as a lubricating medium between adjacent cold-pressed blanks 61.

[0242] Step N33: Vacuum degassing and sealing of the hot pressing mold 62 on which the cold-pressed blank 61 is placed.

[0243] Step N34: The hot pressing mold 62, which has been degassed under vacuum and contains the cold-pressed blank 61, is subjected to hot isostatic pressing to form a combination of the hot pressing mold 62 and the hot-pressed blank 63. The sintering temperature is 580 degrees Celsius, the pressure is 20 MPa, and the holding time is 50 min.

[0244] Step N35: By processing the combination of hot pressing mold 62 and hot pressing blank 63, the hot pressing mold 62 is removed to obtain hot pressing blank 63.

[0245] Step N361: The hot-pressed preform 63 is subjected to solution treatment at 480℃ for 1 hour.

[0246] Step N362: The hot-pressed blank 63 after solution treatment is quenched in cold water.

[0247] N363: The hot-pressed blank 63, which has been quenched in cold water, is subjected to artificial aging treatment at 130°C for 20 hours to obtain the shell preform 4.

[0248] Step N41: The shell preform 4 is machined by CNC to obtain the shell 200.

[0249] In this application, steps N021 and N022 can be performed before step N1 or between step N1 and step N2, and this application does not impose any restrictions on this. In step N022, if nanoscale SiC powder (D50 at 100 nm) is used, its volume fraction in the aluminum alloy substrate is 4%. If submicron-scale SiC powder (D50 at 10 μm) is used, its volume fraction in the aluminum alloy substrate is 18%. Powder mixing can be carried out in a ball mill, and the elastic modulus of the mixed aluminum-based composite material is approximately 105 GPa. In step N1, the first preform 3 can be a hollow cuboid-shaped mobile phone frame formed by cutting profiles, with a thickness of 10 mm. In step N34, hot isostatic pressing sintering can be carried out in a hot press furnace using metal wire as the resistance heating element.

[0250] The casing 200 prepared using the above steps exhibits minimal sintering deformation and high dimensional yield. The bonding surface between the aluminum alloy profile and the aluminum-based composite material is a metallurgical bonding interface 203, ensuring highly reliable strength. Compared to existing technologies, the modulus of the entire casing 200 is increased by 50%, from approximately 70 GPa to over 100 GPa, and the thermal conductivity is also improved from below 120 W / m·K to over 150 W / m·K. Currently, the thinnest plate 112 (battery compartment area C) in the industry's mobile phone casing 200 is 0.2 mm. The casing 200 prepared using the above method can be further thinned to 0.15 mm, increasing the battery capacity by 100 mA while maintaining a fixed mobile phone thickness.

[0251] As shown in Figure 22, in one possible implementation, the method for preparing the shell 200 includes the following steps:

[0252] Step P021: Pre-treat and surface modify the graphite particles to obtain the reinforcing material powder.

[0253] Step P022: Mix graphite particles with 6061 aluminum alloy powder (D50≤20 micrometers) to obtain aluminum-based composite material powder.

[0254] Step P1: Provide a first preform 3; wherein the first preform 3 has a filling space 31, and the material of the first preform 3 is TC4 titanium alloy.

[0255] Step P2: Fill the TC4 titanium alloy filling space 31 with aluminum-based composite powder.

[0256] Step P31: The TC4 titanium alloy profile blank filled with aluminum-based composite material powder is cold-pressed under a hydraulic press at a pressure of 10 MPa for 30 minutes to form a cold-pressed blank 61.

[0257] Step P32: Stack multiple cold-pressed blanks 61 in a hot-pressing mold 62, and use graphite paper 64 with a thickness of 0.6 mm as a lubricating medium between adjacent cold-pressed blanks 61.

[0258] Step P33: Vacuum degassing and sealing of the hot pressing mold 62 on which the cold-pressed blank 61 is placed.

[0259] Step P34: The hot pressing mold 62, which has been degassed under vacuum and contains the cold-pressed blank 61, is subjected to hot isostatic pressing to form a combination of the hot pressing mold 62 and the hot-pressed blank 63. The sintering temperature is 610 degrees Celsius, the pressure is 20 MPa, and the holding time is 30 min.

[0260] Step P35: By processing the combination of hot pressing mold 62 and hot pressing blank 63, the hot pressing mold 62 is removed to obtain the hot pressing blank 63.

[0261] Step P361: The hot-pressed preform 63 is subjected to solution treatment at 480℃ for 1 hour.

[0262] Step P362: The hot-pressed blank 63 after solution treatment is quenched in cold water.

[0263] Step P363: The hot-pressed blank 63 after cold water quenching is subjected to artificial aging treatment at 160℃ for 18 hours to obtain the shell preform 4.

[0264] Step P41: The shell preform 4 is machined by CNC to obtain the shell 200.

[0265] In this application, steps P021 and P022 can be performed before step P1 or between step P1 and step P2; this is not a limitation. In step P022, if graphite particles (D50 ≤ 15 micrometers) are used, their volume fraction in the aluminum alloy substrate is 50%. Powder mixing can be performed in a ball mill. In step P1, the first preform 3 can be a hollow cuboid-shaped mobile phone frame formed by cutting profiles, with a thickness of 10 mm. In step P34, hot isostatic pressing sintering can be performed in a hot press furnace using metal wire as the resistance heating element.

[0266] The shell 200 prepared using the above steps exhibits minimal sintering deformation and high dimensional yield. The bonding surface between the titanium alloy profile and the aluminum-based composite material is a metallurgical interface 203, resulting in high reliability. Compared to existing technologies, the thermal conductivity is increased from below 120 W / m·K to above 400 W / m·K.

[0267] As shown in Figure 23, in one possible implementation, the method for preparing the shell 200 includes the following steps:

[0268] Step Q021: Pre-treat and surface modify the graphite particles to obtain the reinforcing material powder.

[0269] Step Q022: Mix graphite particles with 6061 aluminum alloy powder (D50≤20 micrometers) to obtain aluminum-based composite material powder.

[0270] Step Q1: Provide a first preform 3; wherein the first preform 3 has a filling space 31, and the material of the first preform 3 is 6013 aluminum alloy.

[0271] Step Q2: Fill the 6013 aluminum alloy filling space 31 with aluminum-based composite powder.

[0272] Step Q31: The 6013 aluminum alloy profile blank filled with aluminum-based composite material powder is cold-pressed under a hydraulic press at a pressure of 10 MPa for 30 minutes to form a cold-pressed blank 61.

[0273] Step Q32: Stack multiple cold-pressed blanks 61 in a hot-pressing mold 62, and use graphite paper 64 with a thickness of 0.6 mm as a lubricating medium between adjacent cold-pressed blanks 61.

[0274] Step Q33: Vacuum degassing and sealing of the hot pressing mold 62 on which the cold-pressed blank 61 is placed.

[0275] Step Q34: The hot pressing mold 62, which has been degassed under vacuum and contains the cold-pressed blank 61, is subjected to hot isostatic pressing sintering to form a combination of the hot pressing mold 62 and the hot-pressed blank 63. The sintering temperature is 600 degrees Celsius, the pressure is 15 MPa, and the holding time is 50 min.

[0276] Step L35: By processing the combination of hot pressing mold 62 and hot pressing blank 63, the hot pressing mold 62 is removed to obtain the hot pressing blank 63.

[0277] Step Q361: The hot-pressed preform 63 is subjected to solution treatment at 480℃ for 1 hour.

[0278] Step Q362: The hot-pressed blank 63 after solution treatment is quenched in cold water.

[0279] Step Q363: The hot-pressed blank 63 after cold water quenching is subjected to artificial aging treatment at 160℃ for 18 hours to obtain the shell preform 4.

[0280] Step Q41: The shell preform 4 is machined by CNC to obtain the shell 200.

[0281] In this application, steps Q021 and Q022 can be performed before step Q1 or between step Q1 and step Q2, without limitation. In step Q022, if graphite particles (D50 ≤ 15 micrometers) are used, their volume fraction in the aluminum alloy substrate is 50%. Powder mixing can be carried out in a ball mill. In step Q1, the first preform 3 can be a hollow cuboid-shaped mobile phone frame formed by cutting profiles, with a thickness of 10mm. In step Q34, hot isostatic pressing sintering can be carried out in a hot press furnace using metal wire as the resistance heating element.

[0282] The shell 200 prepared using the above steps exhibits minimal sintering deformation and high dimensional yield. The bonding surface between the aluminum alloy profile and the aluminum-based composite material is a metallurgical interface 203, resulting in high reliability. Compared to existing technologies, the thermal conductivity is increased from below 120 W / m·K to above 400 W / m·K.

[0283] In summary, the shell 200 prepared by the method of this application has higher overall performance. Compared with the existing shells 200 in the industry, it has higher stiffness, elastic modulus increased from 70 GPa to over 90 GPa, strength increased from 370 MPa to over 600 MPa, thermal conductivity increased from below 100 W / m·K to over 200 W / m·K, and can reduce the thickness of the mobile phone middle plate 112 from 0.2 mm to 0.15 mm. Moreover, the shell 200 obtained after isostatic pressing sintering has less deformation and higher dimensional yield.

[0284] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A housing having a middle plate and a frame, the frame being connected to the outer periphery of the middle plate, characterized in that, The housing includes a first part and a second part, wherein the first part is connected to the second part; Furthermore, the first part is made of a metal alloy, the second part is made of a metal matrix composite material, and the interface between the first part and the second part is a metallurgical bonding interface. The metal matrix of the metal alloy in the first part is the same as the metal matrix of the metal matrix composite material in the second part, or the metal matrix of the metal alloy in the first part and the metal matrix composite material in the second part are any two different types of aluminum-based, titanium-based, and magnesium-based materials. Wherein, the first part constitutes the entire frame, and the second part constitutes all areas of the middle plate; or, the first part constitutes the entire frame and a portion of the middle plate, and the second part constitutes another portion of the middle plate excluding that portion.

2. The housing as claimed in claim 1, characterized in that, The first part and the second part are connected by isostatic pressing sintering.

3. The housing as described in claim 1 or 2, characterized in that, When the metal matrix of the metal alloy in the first part is the same as the metal matrix of the metal matrix composite material in the second part, the material of the first part is one of aluminum alloy, titanium alloy, and magnesium alloy, and the material of the second part is one of aluminum matrix composite material, titanium matrix composite material, and magnesium matrix composite material.

4. The housing as described in claim 3, characterized in that, When the first part is made of aluminum alloy and the second part is made of aluminum-based composite material: The first part is made of 6-series aluminum alloy, and the base material of the aluminum-based composite material in the second part is 5-series, 6-series, or 7-series aluminum alloy; or, The first part is made of 7-series aluminum alloy, and the base material of the aluminum-based composite material in the second part is 6-series or 7-series aluminum alloy.

5. The housing as described in claim 1 or 2, characterized in that, The first part is made of titanium alloy, and the base material of the aluminum-based composite material in the second part is 6-series or 7-series aluminum alloy.

6. The housing as described in any one of claims 1-5, characterized in that, The material of the second part is fiber-reinforced metal matrix composite or particle-reinforced metal matrix composite.

7. The housing as claimed in claim 6, characterized in that, When the material of the second part is a particle-reinforced metal matrix composite material, the reinforcing material of the particle-reinforced metal matrix composite material is one, two, or three of the following: SiC, Al2O3, B4C, TiB2, graphene, carbon nanotubes, graphite, and diamond.

8. The housing as claimed in claim 7, characterized in that, When the material of the second part is a particle-reinforced aluminum matrix composite material, and the reinforcing material of the particle-reinforced aluminum matrix composite material is SiC: SiC particles with a diameter of 0-0.2 μm are dispersed in an aluminum alloy substrate at a volume fraction of 0-5%; or, SiC particles with a diameter of 0.5μm-1μm are dispersed in an aluminum alloy substrate at a volume fraction of 0-10%; or, SiC particles with a diameter of 3μm-20μm are dispersed in an aluminum alloy substrate at a volume fraction of 8-25%.

9. The housing as described in any one of claims 1-8, characterized in that, The housing also includes an anodized layer, which is applied to the outer surface of the first portion.

10. An electronic device, characterized in that, Includes the housing as described in any one of claims 1-9.

11. The electronic device as claimed in claim 10, characterized in that, The electronic device further includes a battery assembly, which is installed inside the housing; the housing is a mid-frame, and the area of ​​the mid-plate of the housing corresponding to the battery assembly is the battery compartment area; The electronic device further includes a back cover, the outer periphery of which is connected to the frame; wherein, the middle plate is spaced apart from the back cover, or the middle plate is reused as the back cover.

12. The electronic device as claimed in claim 11, characterized in that, Another portion of the middle plate includes the battery compartment area of ​​the middle plate.

13. The electronic device as claimed in claim 10, characterized in that, The electronic device also includes a rotating shaft mechanism, and the housing serves as the shaft cover for the rotating shaft mechanism; In the thickness direction of the rotating shaft mechanism, one portion of the middle plate is stacked with another portion of the middle plate.

14. A method for preparing a shell, characterized in that, The shell is the shell as described in any one of claims 1-9; the preparation method includes: A first prefabricated component is provided; wherein the first prefabricated component has a filling space, and the material of the first prefabricated component is a metal alloy; The filling space of the first preform is filled with metal matrix composite powder; The first part of the preform filled with metal matrix composite powder is subjected to isostatic pressing sintering to obtain a shell preform; wherein, the shell preform includes the first part of the preform after isostatic pressing sintering and a second part of the preform formed from the metal matrix composite powder, the first part of the preform and the second part of the preform are connected, and the connection interface is a metallurgical bonding interface. The shell is obtained by processing the shell preform; wherein, the first part of the shell is obtained by processing the first part preform of the shell preform, and the second part of the shell is obtained by processing the second part preform of the shell preform.

15. The preparation method according to claim 14, characterized in that, The steps of isostatically pressing and sintering the first preform filled with metal matrix composite powder to obtain the shell preform include: The first part of the preform filled with metal matrix composite powder is cold isostatically pressed to form a cold-pressed blank. The cold-pressed blank is placed in a hot-pressing mold; The hot pressing mold on which the cold-pressed blank is placed is vacuum degassed and sealed. The hot pressing mold containing the cold-pressed blank after vacuum degassing is subjected to hot isostatic pressing sintering to form a combination of the hot pressing mold and the hot pressing blank. The hot-pressed blank is obtained by processing the combination of the hot-pressing mold and the hot-pressed blank and removing the hot-pressing mold. The hot-pressed blank is heat-treated to obtain the shell preform.

16. The preparation method according to claim 15, characterized in that, In the cold isostatic pressing step, the temperature is room temperature, the pressure is 3MPa-15MPa, and the holding time is 5min-45min. In the hot isostatic pressing sintering step, the temperature is 580℃-620℃, the pressure is 5MPa-30MPa, and the holding time is 10min-60min.

17. The preparation method according to claim 15 or 16, characterized in that, The step of heat-treating the hot-pressed blank to obtain the shell preform includes: The hot-pressed preform is subjected to solution treatment at a temperature of 450℃-500℃ for 1-4 hours. The hot-pressed blank, after solution treatment, is then subjected to cold water quenching. The hot-pressed blank, after being quenched in cold water, is subjected to artificial aging treatment at a temperature of 120℃-180℃ for 2h-24h to obtain the shell preform.

18. The preparation method according to any one of claims 14-17, characterized in that, In the step of providing the first prefabricated part, the first prefabricated part is obtained by cutting a metal alloy profile; In the step of filling the filling space of the first preform with metal matrix composite powder, the metal matrix composite powder completely fills the filling space.

19. The preparation method according to any one of claims 14-18, characterized in that, In the step of filling the filling space of the first preform with metal matrix composite powder, the step of preparing the filling metal matrix composite powder includes: The reinforcing preform powder is pretreated and surface modified to obtain the reinforcing powder. The reinforcing material powder is mixed with a base material powder containing a metal matrix to obtain the metal matrix composite powder.

20. The preparation method according to any one of claims 14-19, characterized in that, The steps for manufacturing the shell by processing the shell preform include: The first preform, which is connected to the second preform, is sequentially subjected to one CNC machining, T-processing, nano-injection molding, two CNC machining, grinding and polishing, sandblasting, and anodizing to obtain the shell.

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