Housing manufacturing method, housing and electronic equipment

Abstract

This application provides a method for manufacturing a housing, a housing, and an electronic device. The method for manufacturing the housing includes: providing a metal casting, the metal casting including a metal substrate and a metal outer layer, the metal outer layer being located outside the metal substrate and adjacent to the metal substrate, and the metal outer layer having pores formed therein; and hot-deforming and forging the portion of the metal outer layer away from the metal substrate to obtain a dense metal layer. The housing obtained using this manufacturing method does not require filler material, and the surface uniformity of the housing is good.

Description

Technical Field

[0001] This application relates to the field of electronic device technology, and in particular to a method for preparing a housing, the housing itself, and an electronic device. Background Technology

[0002] Currently, electronic devices on the market often have holes on the outer surface of their casings due to manufacturing issues, resulting in a loose surface structure. Existing methods typically involve using putty to fill these holes, improving the casing's appearance. However, because the casing and the filler are made of different materials, the filler often adheres poorly to the casing, leading to inconsistent surface finish. Summary of the Invention

[0003] The purpose of this application is to provide a method for preparing a housing, a housing, and an electronic device. The housing obtained by this method does not require filler material and has good surface consistency.

[0004] This application provides a method for preparing a shell, the method comprising:

[0005] A metal casting is provided, the metal casting including a metal matrix and a metal outer layer, the metal outer layer being located outside the metal matrix and adjacent to the metal matrix, and the metal outer layer having pores formed therein;

[0006] The portion of the outer metal layer that is away from the metal substrate is hot-deformed and forged to obtain a dense metal layer.

[0007] In the shell preparation method provided in this application embodiment, the portion of the outer metal layer of a metal casting that is away from the metal matrix is ​​subjected to hot deformation forging. This heating deformation causes micro-flow of material in the portion of the outer metal layer away from the metal matrix, specifically micro-flow near the outer surface of the metal casting. After flow, the microstructure in this portion of the outer metal layer becomes homogenized, forming a dense metal layer. During the hot deformation forging process, some pores on the outer surface of the metal casting and in the outer metal layer close, thus closing the pores on the outer surface of the prepared dense metal layer. This results in a low porosity in the dense metal layer, which improves the appearance of the shell. In the shell preparation method provided in this application embodiment, the pores in the dense metal layer formed by hot deformation forging close, eliminating the need for a puttying process and improving surface consistency. Furthermore, compared to the traditional process described above, it eliminates multiple puttying and grinding steps, simplifying the manufacturing process and reducing costs. In addition, by hot-deforming and forging the portion of the outer metal layer that is away from the metal substrate to form a dense metal layer, the structural strength of the shell can be improved.

[0008] In one possible implementation, the step of hot-deforming and forging the portion of the metal outer layer away from the metal substrate to obtain a dense metal layer includes:

[0009] The portion of the outer metal layer that is away from the metal substrate is hot-deformed and forged to obtain a hot-deformed metal layer, wherein the hot-deformed metal layer includes a dense metal layer and a metal allowance layer, with the metal allowance layer located outside the dense metal layer.

[0010] The excess metal layer is removed to obtain the shell. Removing the excess metal layer helps to achieve a pore-free appearance on the outer surface of the shell, thereby improving its overall appearance.

[0011] In one possible implementation, the thickness of the metal allowance layer is ΔH, where ΔH is 0.3 mm to 0.5 mm.

[0012] In one possible implementation, the housing further includes an outer layer, and the method for preparing the housing further includes: preparing the outer layer on the outer surface of the dense layer. Compared to the method of the outer layer being directly attached to the outer surface of the metal casting, a more stable bonding force can be formed between the dense metal layer and the outer layer, and the dense metal layer can exhibit better wear resistance and resistance to outer layer peeling, which is beneficial to improving the bonding ability between the dense metal layer and the outer layer, thereby improving the appearance of the housing.

[0013] In one possible implementation, the hot deformation forging temperature is 200°C to 300°C.

[0014] This application embodiment also provides a housing, which includes a metal substrate, a dense metal layer, and a metal adjacent layer. The dense metal layer is located outside the metal substrate and is spaced apart from the metal substrate. The metal adjacent layer is fixedly connected between the metal substrate and the dense metal layer. Both the dense metal layer and the metal adjacent layer have pores formed in them. The porosity of the dense metal layer is less than that of the metal adjacent layer.

[0015] In the housing provided in this application embodiment, a dense metal layer is formed on the outer side of the metal substrate. The porosity of this dense metal layer is less than that of the adjacent metal layers, resulting in a dense surface structure. The pores on the outer surface of the dense metal layer are small or even nonexistent, eliminating the need for filling material. This avoids the problem of requiring additional filling material in the pores on the outer surface of the housing, thus preventing poor adhesion of the filling material and easy detachment. Furthermore, since no filling material is needed on the outer surface of the dense metal layer, its surface consistency is better, thereby improving the appearance of the housing.

[0016] In one possible implementation, the porosity of the dense metal layer is ≤5%.

[0017] In one possible implementation, the pore diameter of the dense metal layer is ≤50μm.

[0018] In one possible implementation, the thickness of the dense metal layer is D, where D is 0.3 mm to 0.5 mm.

[0019] In one possible implementation, the housing further includes an appearance layer disposed on the outer surface of the dense metal layer. The appearance layer is used to decorate the surface gloss, color, etc., of the housing.

[0020] This application also provides an electronic device, including a functional module and a housing as described above, wherein the functional module is mounted on the housing.

[0021] In one possible implementation, the housing is a mid-frame, and the electronic device also includes a rear cover mounted on the mid-frame. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 A top view of the electronic device provided in an embodiment of this application;

[0024] Figure 2 for Figure 1 A cross-sectional schematic diagram of a portion of the housing structure in the electronic device shown;

[0025] Figure 3 for Figure 2 A schematic diagram of the manufacturing process of the housing in the electronic device shown.

[0026] Figure 4 for Figure 3 A schematic diagram of the cross-sectional structure of the casting mold used to form metal castings in the preparation process shown.

[0027] Figure 5 for Figure 3 A schematic diagram of the cross-sectional structure of the metal casting formed in the preparation process shown.

[0028] Figure 6 for Figure 5 A schematic diagram showing the changes in part A of the metal casting during hot deformation forging to form a metal substrate.

[0029] Figure 7 for Figure 6The diagram shows the changes in a metal casting after hot deformation forging, including the removal of the metal allowance layer and the preparation of the appearance layer. Detailed Implementation

[0030] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0031] Please see Figure 1 , Figure 1 This is a top view of the electronic device 1 provided in an embodiment of this application.

[0032] Electronic device 1 includes a functional module 100 and a housing 300, with the functional module 100 mounted on the housing 300. Electronic device 1 can be a mobile phone, tablet computer, computer (PC), or wearable device, etc. Wearable devices include watches or wristbands, etc. For example, the functional module 100 can be the display screen of electronic device 1, and the housing 300 can be the mid-frame of electronic device 1.

[0033] In this embodiment, electronic device 1 is a mobile phone, functional module 100 is the mobile phone's display screen, and housing 300 is the mobile phone's mid-frame for illustrative purposes. Electronic device 1 also includes a back cover, which is mounted on the mid-frame.

[0034] See Figure 2 , Figure 2 for Figure 1 A cross-sectional schematic diagram of a portion of the housing 300 in the electronic device 1 shown.

[0035] The housing 300 includes a metal substrate 10 and an outer layer 30, the outer layer 30 being attached to the outer surface of the metal substrate 10. In this embodiment, "metal" includes pure metals and metal alloys. For example, the metal substrate 10 may be made of magnesium alloy or aluminum alloy.

[0036] Specifically, the outer surface of the metal substrate 10 includes an appearance surface 101 and a non-appearance surface 102. The non-appearance surface 102 is connected to the appearance surface 101. Here, the appearance surface 101 of the metal substrate 10 refers to the outer surface of the metal substrate 10 that can be observed by the user in the assembled electronic device 1, and the non-appearance surface 102 refers to the outer surface of the metal substrate 10 that is not observed by the user in the assembled electronic device 1.

[0037] From the outer surface 101 of the metal substrate 10 and away from the outer side of the metal substrate 10, the metal substrate 10 sequentially includes a dense metal layer 11, a metal adjacent layer 13, and a metal matrix 15. The metal adjacent layer 13 connects the dense metal layer 11 and the metal matrix 15 to achieve adjacency between the metal adjacent layer 13 and the dense metal layer 11, and is located on the side of the dense metal layer 11 away from the outer side of the metal substrate 10. Specifically, the outer surface of the dense metal layer 11 is the outer surface of the metal substrate 10, and the outer surface of the dense metal layer 11 includes the outer surface 101. Both the dense metal layer 11 and the metal adjacent layer 13 have pores 103 formed therein. The metal matrix 15 has virtually no pores 103. In this embodiment, the pore diameter of the pores 103 in the dense metal layer 11 is ≤50μm.

[0038] The thickness of the dense metal layer 11 is D, extending from the outer surface 101 of the metal substrate 10 and in a direction away from the outer side of the metal substrate 10. For example, D is 0.3 mm to 0.5 mm. The thickness of the dense metal layer 11 is measured as follows: Figure 2 As shown, a cross-sectional tangential section is made on the metal substrate 10 along the direction perpendicular to the surface 101. The boundary is simulated in the area with holes 103, and the boundary line between the dense metal layer 11 and the adjacent metal layer 13 is drawn. The distance between the boundary line between the dense metal layer 11 and the adjacent metal layer 13 and the cross-sectional line of the surface 101 is the thickness D of the dense metal layer 11.

[0039] In this embodiment, the dense metal layer 11, the adjacent metal layer 13, and the metal substrate 15 are made of the same material. The porosity of the dense metal layer 11 is greater than that of the metal substrate 15, and the porosity of the dense metal layer 11 is less than that of the adjacent metal layer 13. In this embodiment, the porosity of the dense metal layer 11 is ≤5%. The calculation method for "porosity of dense metal layer 11" is as follows: According to the above measurement method, the boundary line between the dense metal layer 11 and the adjacent metal layer 13 is drawn to the cross-sectional line of the surface 101, forming a region of dense metal layer 11. Within the region of dense metal layer 11, the total area of ​​the region of dense metal layer 11 is S1, the area of ​​a single hole 103 is S11, and the number of holes 103 is N1. The porosity of dense metal layer 11 = area of ​​holes 103 within the region of dense metal layer 11 * number of holes 103 / total area of ​​region of dense metal layer 11 = S11 * N1 / S1.

[0040] Similarly, the calculation method for the "porosity of the metal adjacent layer 13" is as follows: Following the measurement method described above, the boundary line between the metal adjacent layer 13 and the metal substrate 15 is drawn. The region of the metal adjacent layer 13 is formed between the boundary line between the metal dense layer 11 and the metal adjacent layer 13 and the boundary line between the metal adjacent layer 13 and the metal substrate 15. Within the region of the metal adjacent layer 13, the total area of ​​the region is S2, the area of ​​a single pore 103 is S22, and the number of pores 103 is N2. The porosity of the metal adjacent layer 13 = area of ​​pores 103 within the region of the metal adjacent layer 13 * number of pores 103 / total area of ​​the region of the metal adjacent layer 13 = S22 * N2 / S2.

[0041] The appearance layer 30 is attached to the outer surface of the dense metal layer 11, that is, to the surface of the dense metal layer 11 facing away from the adjacent metal layer 13, so that the appearance layer 30 is attached to the outer surface 101 of the metal substrate 10, thereby achieving the attachment of the appearance layer 30 to the outer surface of the metal substrate 10. The appearance layer 30 can be used for decorative purposes such as surface gloss and color of the housing 300. For example, the appearance layer 30 can be an organic resin appearance layer. In this embodiment, the appearance layer 30 may include a primer layer, a middle coat layer, and a top coat layer. The primer layer is attached to the outer surface of the dense metal layer 11, the middle coat layer is attached to the surface of the primer layer facing away from the dense metal layer 11, and the top coat layer is attached to the surface of the middle coat layer facing away from the primer layer.

[0042] In the housing 300 provided in this embodiment, a dense metal layer 11 is provided on the outer side of the metal substrate 15. The porosity of the dense metal layer 11 is less than that of the adjacent metal layer 13, resulting in a dense surface structure of the dense metal layer 11. The pores on the outer surface of the dense metal layer 11 are small or even non-existent, eliminating the need for filling material. This avoids the problem of needing to fill the pores on the outer surface of the housing 300 with additional material, thus preventing the filler material from easily falling off due to poor adhesion. Furthermore, since no filling material is needed on the outer surface of the dense metal layer 11, the outer surface of the dense metal layer 11 has better consistency, thereby improving the appearance of the housing 300.

[0043] See Figure 3 , Figure 3 for Figure 2 A schematic diagram of the fabrication process of the housing 300 in the electronic device 1 shown.

[0044] This application embodiment also provides a method for preparing the above-mentioned shell 300, including:

[0045] S1. Provide a metal casting 110. For details, please refer to [link / reference]. Figure 4 , Figure 4 for Figure 3 The diagram shows a cross-sectional view of the casting mold 120 used to cast the metal casting 110 in the manufacturing process. The casting mold 120 has a cavity 121, a first opening 123, and a second opening 125. The cavity 121 is located inside the casting mold 120, and both the first opening 123 and the second opening 125 communicate with the cavity 121. Molten metal is poured into the cavity 121 through the first opening 123. Excess molten metal overflows from the second opening 125, filling the entire cavity 121 and cooling within it to form the metal casting 110.

[0046] During the casting process of the metal casting 110, on the one hand, because the first opening 123 and the second opening 125 are in contact with the outer surface of the metal casting 110, gas can easily enter the part of the metal casting 110 near the outer surface (e.g., ...) through the first opening 123 and the second opening 125. Figure 5 In the metal outer layer 12 of the metal casting 110 shown, it is easy to cause holes 103 to form on the outer surface and near the outer surface of the metal casting 110 after casting (see Figure 5 On the other hand, some substances contained in the metal raw material of the metal casting 110 can vaporize at high temperatures, which will also cause pores 103 to form on the outer surface and near the outer surface of the metal casting 110 (see...). Figure 5 ).

[0047] See also Figure 5 , Figure 5 for Figure 3 This is a schematic cross-sectional view of the metal casting 110 formed in the manufacturing process shown. From the outer surface of the metal casting 110 and away from its outer side, the metal casting 110 sequentially includes a metal outer surface layer 12 and a metal substrate 15 adjacent to the metal outer surface layer 12. The metal outer surface layer 12 faces the outer side of the metal casting 110, and pores 103 are formed in the metal outer surface layer 12. For example, the thickness of the metal outer surface layer 12 is W. The thickness W of the metal outer surface layer 12 can be measured using the same method as the thickness measurement of the dense metal layer 11 described above.

[0048] S2. The portion of the outer metal layer 12 facing away from the metal substrate 15 is hot-deformed and forged to obtain a dense metal layer 11. In this embodiment, the metal casting 110 is hot-deformed and forged to obtain the metal substrate 10. For details, please refer to [link to relevant documentation]. Figure 5The outer metal outer layer 12, extending from the outer surface of the metal casting 110 and in a direction away from the outer side of the metal casting 110, includes a surface layer 124 and a metal adjacent layer 13. The surface layer 124 faces the outer side of the metal casting 110, and the metal adjacent layer 13 connects the surface layer 124 and the metal substrate 15, so that the metal adjacent layer 13 is adjacent to the surface layer 124 and located on the side of the surface layer 124 away from the outer surface of the metal casting 110. The surface layer 124 and the metal adjacent layer 13 are made of the same material, and both the surface layer 124 and the metal adjacent layer 13 have multiple pores 103 formed within them. Before hot deformation forging of the outer metal outer layer 12 in the metal casting 110, the boundary between the surface layer 124 and the metal adjacent layer 13 in the outer metal outer layer 12 is not obvious, and the multiple pores 103 in the outer metal outer layer 12 are of uneven size and irregularly distributed in the areas of the surface layer 124 and the metal adjacent layer 13.

[0049] See also Figure 6 , Figure 6 for Figure 5This diagram illustrates the changes in part A of the metal casting 110 during hot deformation forging to form the metal substrate 10. Hot deformation forging is performed on the surface layer 124 of the outer metal layer 12, compressing it to form a dense metal layer 11, thus achieving the preparation of the metal substrate 10 from the metal casting 110. Specifically, during the hot deformation forging process of the metal casting 110, the surface layer 124 is heated and deformed, compressing it to form the dense metal layer 11. Micro-flow occurs in the material of the surface layer 124 within the outer metal layer 12. After this flow, the pores 103 on the outer surface of the metal casting 110 and in the surface layer 124 close, while the pores 103 in the adjacent metal layer 13 remain essentially unchanged. This results in the porosity of the dense metal layer 11 being lower than that of the adjacent metal layer 13. For example, the hot deformation forging temperature is 200℃~300℃. After hot deformation forging, the metal casting 110 exhibits a deformation of ΔW relative to the surface layer 124 in the thickness direction, where ΔW is 0.3mm to 0.5mm. This means the metal substrate 10 exhibits a deformation of ΔW relative to the metal casting 110 in the thickness direction of the surface layer 124, which is 0.3mm to 0.5mm. In this embodiment, the outer surface of the metal casting 110 includes a surface to be processed. During hot deformation forging, the surface to be processed is compressed, causing the surface layer 124 to form a hot-deformed metal layer 126. The surface to be processed of the metal casting 110 becomes the outer surface 101 of the metal substrate 10. For example, before hot deformation forging, the thickness of the outer metal layer 12 of the metal casting 110 can be 0.5mm to 1.0mm, meaning the thickness of the portion of the metal casting 110 near the surface to be processed is 0.5mm to 1.0mm. The metal heat-deformation layer 126 includes a metal dense layer 11 and a metal reserve layer 17. The metal dense layer 11 is connected between the metal adjacent layer 13 and the metal reserve layer 17, and the metal reserve layer 17 is located outside the metal dense layer 11.

[0050] See also Figure 7 , Figure 7 for Figure 6 The diagram shows the changes in the metal casting 110 after hot deformation forging, including the removal of the metal allowance layer 17 and the preparation of the appearance layer 30.

[0051] S3. Remove the excess metal layer 17 to obtain the housing 300. In this embodiment, CNC (Computerized Numerical Control) machining is used to remove the excess metal layer 17 in the metal heat-deformation layer 126 along its thickness direction. For example, the thickness of the excess metal layer 17 is ΔH, which is 0.3mm to 0.5mm. After removing the excess metal layer 17, the thickness of the dense metal layer 11 is D. Removing the excess metal layer 17 helps achieve a hole-free appearance on the outer surface of the metal substrate 10, improving the appearance of the metal substrate 10 and thus improving the appearance of the housing 300. It is understood that the thickness of the excess metal layer 17 can be adjusted according to actual needs.

[0052] S4. An appearance layer 30 is prepared on the outer surface of the dense metal layer 11. Exemplarily, the appearance layer 30 can be prepared by spraying or physical vapor deposition (PVD). In this embodiment, before step S4, a step of polishing the outer surface of the dense metal layer 11 is included to remove tool marks on the outer surface of the dense metal layer 11. In some embodiments, the polished metal substrate 10 can also be subjected to sandblasting anodizing surface treatment to improve the adhesion of the appearance layer 30 to the outer surface of the dense metal layer 11 on the metal substrate 10, while also improving the corrosion resistance and aesthetics of the metal substrate 10.

[0053] The shell 300 prepared according to the embodiment of this application was used as a simulation sample. After simulation, the shell 300 met the reliability requirements in terms of bending resistance and drop resistance.

[0054] Currently, metal castings 110 are mainly manufactured using CNC (Computerized Numerical Control) machining, which is time-consuming and costly. This application provides a method for manufacturing a housing 300 by casting the metal casting 110. Compared to CNC machining, this method is faster and less expensive.

[0055] Furthermore, after casting, the metal casting 110 will have holes 103 formed on its outer surface, which affects the appearance of the metal casting 110 and consequently the appearance of the shell 300. In traditional processes for manufacturing the shell 300 using the metal casting 110, the metal casting 110 needs to be CNC machined first, then its outer surface ground. Next, a filler material is used to fill the holes 103 on the outer surface of the metal casting 110, and the filler material is baked to solidify. Then, the outer surface of the metal casting 110 is ground again, and this process of filling, baking, and grinding is repeated until the appearance of the metal casting 110 is satisfactory. Finally, an appearance layer 30 is coated on the outer surface of the metal casting 110 to form the shell 300. After removing the surface layer 30, the metal casting 110 exposed by the shell 300 prepared in this way is exposed by HF acid etching. The crystalline structure of the metal casting 110 is exposed. The location of the filler can be clearly observed on the surface of the metal casting 110. There is a clear boundary between the filler location and the location without filler. The surface of the shell 300 has poor consistency and an uneven appearance. The manufacturing process is long, and the appearance needs to be polished, filled, and baked multiple times. The yield is low and the manufacturing cost is high.

[0056] The method for preparing the shell 300 provided in this application involves hot deformation forging of the portion of the outer metal layer 12 of the metal casting 110 that is away from the metal substrate 15. This hot deformation causes micro-flow of material in the portion of the outer metal layer 12 away from the metal substrate 15, specifically, micro-flow occurs in the portion of the metal casting 110 near the outer surface. After this flow, the microstructure in the portion of the outer metal layer 12 away from the metal substrate 15 becomes homogenized, forming a dense metal layer 11. During this hot deformation forging process, some pores 103 on the outer surface of the metal casting 110 and in the outer metal layer 12 are closed, thus closing the pores 103 on the outer surface of the prepared dense metal layer 11. The resulting dense metal layer 11 has low porosity, which improves the appearance of the prepared metal substrate 10, and consequently improves the appearance of the shell 300. In the method for preparing the shell 300 provided in this application embodiment, the pores 103 of the dense metal layer 11 formed by hot deformation forging are closed. The resulting shell 300 does not require a putty filling process, improving the surface uniformity of the metal substrate 10, thereby improving the surface uniformity of the shell 300. Furthermore, compared to the aforementioned traditional process, it eliminates the need for multiple putty filling and polishing steps, simplifying the manufacturing process and reducing costs. In addition, by forming the dense metal layer 11 from the portion of the outer metal layer 12 away from the metal substrate 15 through hot deformation forging, the structural strength of the metal substrate 10 can be improved, thereby enhancing the structural strength of the shell 300.

[0057] In addition, compared to the method where the outer layer 30 is directly attached to the outer surface of the metal casting 110, in the embodiment of this application, the portion of the metal outer layer 12 of the metal casting 110 that is away from the metal substrate 15 is compressed to form a dense metal layer 11. The dense metal layer 11 and the outer layer 30 can form a more stable bonding force, and the dense metal layer 11 can exhibit better wear resistance and resistance to the outer layer 30 falling off, which is beneficial to improving the bonding ability between the metal substrate 10 and the outer layer 30, thereby improving the appearance of the housing 300.

[0058] The above-disclosed embodiments are merely preferred embodiments of this application and should not be construed as limiting the scope of this application. Those skilled in the art will understand that all or part of the processes for implementing the above embodiments and equivalent variations made in accordance with the claims of this application are still within the scope of this application.

Claims

1. A method for preparing a shell, characterized in that, The method for preparing the shell includes: A metal casting is provided, the metal casting including a metal matrix and a metal outer surface layer, the metal outer surface layer being located outside the metal matrix and adjacent to the metal matrix, the metal outer surface layer having pores formed therein, extending from the outer surface of the metal casting and in a direction away from the outer side of the metal casting, the metal outer surface layer including a surface layer and a metal adjacent layer, the surface layer facing the outer side of the metal casting, the metal adjacent layer connecting the surface layer and the metal matrix; The portion of the outer metal layer facing away from the metal substrate is subjected to hot deformation forging. The outer layer is then subjected to hot deformation forging to obtain a dense metal layer. The porosity of the dense metal layer is ≤5%. The hot deformation forging temperature is 200℃~300℃. The porosity of the dense metal layer is greater than that of the metal substrate, and the porosity of the dense metal layer is less than that of the adjacent metal layer.

2. The method for preparing the shell according to claim 1, characterized in that, The step of hot-deforming and forging the portion of the outer metal layer away from the metal substrate to obtain a dense metal layer includes: The portion of the outer metal layer that is away from the metal substrate is hot-deformed and forged to obtain a hot-deformed metal layer, wherein the hot-deformed metal layer includes a dense metal layer and a metal allowance layer, and the metal allowance layer is located outside the dense metal layer; Remove the metal excess layer to obtain the housing.

3. The method for preparing the shell according to claim 2, characterized in that, The thickness of the metal allowance layer is ΔH, which is 0.3 mm to 0.5 mm.

4. The method for preparing the shell according to any one of claims 1 to 3, characterized in that, The housing further includes an outer layer, and the method for preparing the housing further includes: preparing the outer layer on the outer surface of the dense layer.

5. A housing, characterized in that, The shell is prepared according to the method of any one of claims 1 to 4. The shell includes a metal substrate, a dense metal layer, and a metal adjacent layer. The dense metal layer is located outside the metal substrate and is spaced apart from the metal substrate. The metal adjacent layer is fixedly connected between the metal substrate and the dense metal layer. Pores are formed in both the dense metal layer and the metal adjacent layer. The porosity of the dense metal layer is less than that of the metal adjacent layer, and the porosity of the dense metal layer is ≤5%.

6. The housing according to claim 5, characterized in that, The diameter of the pores in the dense metal layer is ≤50 μm.

7. The housing according to claim 5, characterized in that, The thickness of the dense metal layer is D, where D is 0.3 mm to 0.5 mm.

8. The housing according to any one of claims 5 to 7, characterized in that, The housing also includes an outer layer disposed on the outer surface of the dense metal layer.

9. An electronic device, characterized in that, It includes a functional module and a housing as described in any one of claims 5 to 8, wherein the functional module is mounted on the housing.

10. The electronic device according to claim 9, characterized in that, The housing is a mid-frame, and the electronic device also includes a rear cover, which is mounted on the mid-frame.

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