Shell preparation method, shell and electronic equipment

Abstract

The invention provides a preparation method of a shell, the shell and electronic equipment, and the preparation method of the shell comprises the steps that a metal casting is provided, the metal casting comprises a metal base body and a metal outer surface layer, the metal outer surface layer is located on the outer side of the metal base body and is adjacent to the metal base body, and holes are formed in the metal outer surface layer; and performing thermal deformation forging on the part, deviating from the metal matrix, of the metal outer surface layer to obtain the metal compact layer. The shell obtained through the preparation method does not need to be filled with materials, and the surface consistency of the shell is good.

Description

Method for preparing housing, housing and electronic device

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on December 14, 2023, with application number 202311719664.9 and application name “Method for preparing a shell, shell and electronic device”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the technical field of electronic equipment, and in particular to a method for preparing a shell, a shell, and an electronic device. Background Art

[0003] Electronic devices currently on the market often have holes on the outer surface of their casings due to manufacturing issues, resulting in a loose surface structure. Currently, these holes are typically filled with a filling material using a puttying process to enhance the casing's appearance. However, since the casing and the filling material are made of different materials, the filling material often has poor adhesion to the casing, resulting in poor surface consistency.

[0004] Summary of the Invention

[0005] The purpose of the embodiments of the present application is to provide a method for preparing a shell, a shell, and an electronic device. The shell obtained by the preparation method does not require filling materials, and the surface consistency of the shell is good.

[0006] The present invention provides a method for preparing a housing, which includes:

[0007] A metal casting is provided, comprising a metal base and a metal outer layer, wherein the metal outer layer is located outside the metal base and is adjacent to the metal base, and holes are formed in the metal outer layer;

[0008] The portion of the metal outer layer that is away from the metal matrix is ​​subjected to hot deformation forging to obtain a dense metal layer.

[0009] In the preparation method of the shell provided in the embodiment of the present application, the portion of the metal outer layer in the metal casting that is away from the metal matrix is ​​subjected to hot deformation forging and processing. By using the heat deformation method, the material in the portion of the metal outer layer in the metal casting that is away from the metal matrix undergoes micro-flow, that is, the portion close to the outer surface of the metal casting undergoes micro-flow. After the flow, the structure in the portion of the metal outer layer that is away from the metal matrix is ​​homogenized and a metal dense layer is formed. At this time, during the hot deformation forging process, some of the pores on the outer surface of the metal casting and the metal outer layer are closed to achieve closure of the pores on the outer surface of the prepared metal dense layer. The porosity of the obtained metal dense layer is low, which is beneficial to improving the appearance of the shell. In the preparation method of the shell provided in the embodiment of the present application, the pores of the metal dense layer formed by hot deformation forging are closed, and the prepared shell does not need to undergo a filling process, which is beneficial to improving the surface consistency of the shell. At the same time, compared with the above-mentioned traditional process, it saves multiple filling and polishing steps, and the manufacturing process is simple and low in cost. In addition, by forming a dense metal layer through hot deformation forging of the portion of the metal outer layer that is away from the metal matrix, the structural strength of the shell is improved.

[0010] In a possible embodiment, the step of hot-deforming and forging the portion of the metal outer layer facing away from the metal substrate to obtain the dense metal layer includes:

[0011] Performing hot deformation forging on a portion of the metal outer layer away from the metal substrate to obtain a metal hot deformation layer, wherein the metal hot deformation layer includes a metal dense layer and a metal surplus layer, and the metal surplus layer is located outside the metal dense layer;

[0012] The excess metal layer is removed to obtain the shell. By removing the excess metal layer, the outer surface of the shell is facilitated to achieve a hole-free appearance, thereby improving the appearance of the shell.

[0013] In a possible implementation manner, the thickness of the metal residue layer is ΔH, and ΔH is 0.3 mm to 0.5 mm.

[0014] In one possible embodiment, the housing further includes an exterior layer, and the method for preparing the housing further includes forming the exterior layer on the outer surface of the dense layer. Compared to directly attaching the exterior layer to the outer surface of the metal casting, the dense metal layer and the exterior layer can form a more stable grip, and the dense metal layer can exhibit better wear resistance and resistance to exterior layer shedding, thereby improving the bonding between the dense metal layer and the exterior layer, thereby enhancing the appearance of the housing.

[0015] In a possible implementation manner, the temperature of the hot deformation forging is 200°C to 300°C.

[0016] An embodiment of the present application also provides a shell, which includes a metal base, a metal dense layer and a metal adjacent layer. The metal dense layer is located on the outside of the metal base and is spaced apart from the metal base. The metal adjacent layer is fixedly connected between the metal base and the metal dense layer. Holes are formed in the metal dense layer and the metal adjacent layer. The porosity of the metal dense layer is smaller than the porosity of the metal adjacent layer.

[0017] In the shell provided by the embodiment of the present application, a dense metal layer is provided on the outside of the metal substrate, and the porosity of the dense metal layer is less than that of the adjacent metal layer, so that the surface structure of the dense metal layer is dense, the holes on the outer surface of the dense metal layer are small or even non-existent, and the dense metal layer does not need to be filled with a filling material, thus avoiding the problem of the existing need to fill the holes on the outer surface of the shell with additional filling material, thereby avoiding the problem of the filling material having poor adhesion to the shell and being easy to fall off. At the same time, because the outer surface of the dense metal layer does not need to be filled with a filling material, the outer surface of the dense metal layer is more consistent, which is conducive to improving the appearance of the shell.

[0018] In one possible embodiment, the porosity of the metal dense layer is ≤5%.

[0019] In a possible embodiment, the diameter of the holes in the dense metal layer is ≤50 μm.

[0020] In a possible implementation manner, the thickness of the metal dense layer is D, and D is 0.3 mm to 0.5 mm.

[0021] In a possible embodiment, the shell further includes an appearance layer, which is disposed on the outer surface of the metal dense layer. The appearance layer is provided to decorate the surface gloss and color of the shell.

[0022] An embodiment of the present application further provides an electronic device, comprising a functional module and a housing as described above, wherein the functional module is installed in the housing.

[0023] In a possible implementation, the housing is a middle frame, and the electronic device further includes a back cover mounted on the middle frame. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0025] FIG1 is a schematic diagram of a top view of an electronic device provided in an embodiment of the present application;

[0026] FIG2 is a schematic cross-sectional view of a portion of the housing structure of the electronic device shown in FIG1 ;

[0027] FIG3 is a schematic diagram of the process for preparing the housing of the electronic device shown in FIG2 ;

[0028] FIG4 is a schematic cross-sectional view of a casting mold for forming a metal casting in the preparation process shown in FIG3 ;

[0029] FIG5 is a schematic diagram of the cross-sectional structure of the metal casting formed in the preparation process shown in FIG3;

[0030] FIG6 is a schematic diagram showing the changes in the metal substrate formed by hot deformation and forging in portion A of the metal casting shown in FIG5 ;

[0031] FIG7 is a schematic diagram showing the changes in removing the metal remainder layer and preparing the appearance layer of the metal casting after hot deformation forging shown in FIG6 . DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0033] Please refer to FIG1 , which is a schematic top view of the structure of an electronic device 1 provided in an embodiment of the present application.

[0034] Electronic device 1 includes a functional module 100 and a housing 300, wherein the functional module 100 is mounted on the housing 300. The electronic device 1 may be a mobile phone, tablet computer, personal computer (PC), or wearable device. Wearable devices include watches or bracelets. For example, the functional module 100 may be the display screen of the electronic device 1, and the housing 300 may be the middle frame of the electronic device 1.

[0035] In this embodiment, the electronic device 1 is a mobile phone, the functional module 100 is a display screen of the mobile phone, and the housing 300 is a middle frame of the mobile phone. The electronic device 1 also includes a back cover, which is mounted on the middle frame.

[0036] Please refer to FIG. 2 , which is a schematic cross-sectional view of a portion of the housing 300 of the electronic device 1 shown in FIG. 1 .

[0037] The housing 300 includes a metal substrate 10 and an exterior layer 30 , which is attached to the outer surface of the metal substrate 10 . The term "metal" as used in the present embodiment includes both pure metals and metal alloys. For example, the metal substrate 10 may be made of a magnesium alloy or an aluminum alloy.

[0038] Specifically, the outer surface of the metal substrate 10 includes an exterior surface 101 and a non-exterior surface 102. The non-exterior surface 102 is connected to the exterior surface 101. The exterior surface 101 of the metal substrate 10 is the surface of the metal substrate 10 visible to the user of the assembled electronic device 1, while the non-exterior surface 102 is the surface of the metal substrate 10 not visible to the user of the assembled electronic device 1.

[0039] From the appearance surface 101 of the metal substrate 10 and in the direction away from the outside of the metal substrate 10, the metal substrate 10 includes a metal dense layer 11, a metal adjacent layer 13 and a metal base 15 in sequence. The metal adjacent layer 13 is connected between the metal dense layer 11 and the metal base 15 to achieve the metal adjacent layer 13 being adjacent to the metal dense layer 11, and is located on the side of the metal dense layer 11 away from the outside of the metal substrate 10. Specifically, the outer surface of the metal dense layer 11 is the outer surface of the metal substrate 10, and the outer surface of the metal dense layer 11 includes the appearance surface 101. Among them, holes 103 are formed in the metal dense layer 11 and the metal adjacent layer 13. There are basically no holes 103 in the metal base 15. In this embodiment, the hole diameter of the hole 103 in the metal dense layer 11 is ≤50μm.

[0040] The thickness of the metal dense layer 11 is D, measured from the exterior surface 101 of the metal substrate 10 and in a direction away from the exterior surface of the metal substrate 10. For example, D is 0.3 mm to 0.5 mm. The thickness of the metal dense layer 11 is measured as follows: as shown in FIG2 , a tangential section is made of the metal substrate 10 in a direction perpendicular to the exterior surface 101, a boundary is simulated in the region having the hole 103, and a boundary line between the metal dense layer 11 and the metal adjacent layer 13 is drawn. The distance between the boundary line between the metal dense layer 11 and the metal adjacent layer 13 and the cross-section line of the exterior surface 101 is measured to be the thickness D of the metal dense layer 11.

[0041] In this embodiment, the metal dense layer 11, the metal adjacent layer 13, and the metal base 15 are made of the same material. The porosity of the metal dense layer 11 is greater than the porosity of the metal base 15, and the porosity of the metal dense layer 11 is less than the porosity of the metal adjacent layer 13. In this embodiment, the porosity of the metal dense layer 11 is ≤5%. Among them, the "porosity of the metal dense layer 11" is calculated as follows: according to the above-mentioned measurement method, a metal dense layer 11 area is formed between the boundary line between the drawn metal dense layer 11 and the metal adjacent layer 13 and the cross-section line of the appearance surface 101. Within the area of ​​the metal dense layer 11, the total area of ​​the area of ​​the metal dense layer 11 is S1, the area of ​​a single hole 103 is S11, and the number of holes 103 is N1. The porosity of the metal dense layer 11 = the area of ​​the holes 103 in the metal dense layer 11 area * the number of holes 103 / the total area of ​​the metal dense layer 11 area = S11*N1 / S1.

[0042] Similarly, the "porosity of the metal adjacent layer 13" is calculated as follows: according to the above-mentioned measurement method, the boundary line between the metal adjacent layer 13 and the metal substrate 15 is drawn. The metal adjacent layer 13 region is formed from the boundary line between the metal dense layer 11 and the metal adjacent layer 13 to the boundary line between the metal adjacent layer 13 and the metal substrate 15. Within the metal adjacent layer 13 region, the total area of ​​the metal adjacent layer 13 region is S2, the area of ​​a single hole 103 is S22, and the number of holes 103 is N2. The porosity of the metal adjacent layer 13 = the area of ​​the holes 103 in the metal adjacent layer 13 region * the number of holes 103 / the total area of ​​the metal adjacent layer 13 region = S22 * N2 / S2.

[0043] The appearance layer 30 is attached to the outer surface of the metal dense layer 11, that is, to the surface of the metal dense layer 11 facing away from the metal adjacent layer 13, so that the appearance layer 30 is attached to the appearance surface 101 of the metal substrate 10, thereby achieving the appearance layer 30 being attached to the outer surface of the metal substrate 10. The appearance layer 30 can be used for decorative purposes such as the surface gloss and color of the shell 300. Exemplarily, the appearance layer 30 can be an organic resin appearance layer. In this embodiment, the appearance layer 30 can include a primer layer, a mid-coat layer, and a topcoat layer. The primer layer is attached to the outer surface of the metal dense layer 11, the mid-coat layer is attached to the surface of the primer layer facing away from the metal dense layer 11, and the topcoat layer is attached to the surface of the mid-coat layer facing away from the primer layer.

[0044] In the housing 300 provided in the embodiment of the present application, a metal dense layer 11 is provided on the outside of the metal base 15, and the porosity of the metal dense layer 11 is less than the porosity of the metal adjacent layer 13, so that the surface structure of the metal dense layer 11 is dense, and the holes on the outer surface of the metal dense layer 11 are small or even non-existent. The metal dense layer 11 does not need to be filled with a filling material, thus avoiding the existing problem of needing to fill the holes on the outer surface of the housing 300 with additional filling material, thereby avoiding the problem of the filling material having poor adhesion to the housing 300 and being easy to fall off. At the same time, because the outer surface of the metal dense layer 11 does not need to be filled with a filling material, the outer surface of the metal dense layer 11 is more consistent, which is conducive to improving the appearance of the housing 300.

[0045] Referring to FIG. 3 , FIG. 3 is a schematic diagram illustrating a process for preparing the housing 300 of the electronic device 1 shown in FIG. 2 .

[0046] The present embodiment further provides a method for preparing the housing 300, including:

[0047] S1. Provide a metal casting 110. Specifically, refer to Figure 4, which is a schematic diagram of the cross-sectional structure of a casting mold 120 for casting the metal casting 110 in the preparation process shown in Figure 3. Take the casting mold 120, which is provided with a cavity 121, a first opening 123 and a second opening 125. The cavity 121 is provided on the inner side of the casting mold 120, and the first opening 123 and the second opening 125 are both connected to the cavity 121. Molten metal raw material is poured into the cavity 121 from the first opening 123, and excess molten metal raw material can overflow from the second opening 125. The molten metal raw material fills the entire cavity 121 and is cooled in the cavity 121 to form the metal casting 110.

[0048] 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 portion of the metal casting 110 near the exterior surface (the metal outer layer 12 of the metal casting 110 shown in FIG5 ) through the first opening 123 and the second opening 125, thereby easily causing holes 103 to form in the exterior surface and the portion near the exterior surface of the metal casting 110 after casting (see FIG5 ). On the other hand, some substances contained in the metal raw material of the metal casting 110 can vaporize at high temperatures, which can also cause holes 103 to form in the exterior surface and the portion near the exterior surface of the metal casting 110 (see FIG5 ).

[0049] Referring to FIG. 5 , FIG. 5 is a schematic diagram of the cross-sectional structure of the metal casting 110 formed in the preparation process shown in FIG. From the outer surface of the metal casting 110 and away from the outer side of the metal casting 110, the metal casting 110 includes, in sequence, a metal outer layer 12 and a metal substrate 15 adjacent to the metal outer layer 12. The metal outer layer 12 faces the outer side of the metal casting 110, and a hole 103 is formed in the metal outer layer 12. Exemplarily, the thickness of the metal outer layer 12 is W. The thickness W of the metal outer layer 12 can be measured with reference to the aforementioned method for measuring the thickness of the metal dense layer 11.

[0050] S2. The portion of the metal outer surface layer 12 facing away from the metal base 15 is subjected to hot deformation forging to obtain a metal dense layer 11. In this embodiment, the metal casting 110 is subjected to hot deformation forging to obtain the metal base material 10. Specifically, referring to Figure 5, from the outer surface of the metal casting 110 and in the direction away from the outer side of the metal casting 110, the metal outer surface layer 12 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 is connected between the surface layer 124 and the metal base 15 to achieve the metal adjacent layer 13 being adjacent to the surface layer 124, and is located on the side of the surface layer 124 facing 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 a plurality of holes 103 are formed in both the surface layer 124 and the metal adjacent layer 13. Before the metal outer layer 12 in the metal casting 110 is subjected to hot deformation forging, the boundary between the surface layer 124 and the metal adjacent layer 13 in the metal outer layer 12 is not obvious, and the multiple holes 103 in the metal outer layer 12 are uneven in size and are irregularly distributed in the area between the surface layer 124 and the metal adjacent layer 13.

[0051] Referring to FIG6 , FIG6 is a schematic diagram of the changes in portion A of the metal casting 110 shown in FIG5 during hot deformation forging to form the metal substrate 10. The surface layer 124 in the metal outer layer 12 is subjected to hot deformation forging, and the surface layer 124 is extruded to form a metal dense layer 11, so as to achieve the metal substrate 10 prepared by hot deformation forging of the metal casting 110. Specifically, during the hot deformation forging process of the metal casting 110, the surface layer 124 is heated and deformed, and the surface layer 124 is extruded to form a metal dense layer 11. The material of the surface layer 124 in the metal outer layer 12 undergoes micro-flow. After the flow, the outer surface of the metal casting 110 and the pores 103 in the surface layer 124 are closed, while the pores 103 in the metal adjacent layer 13 are substantially unchanged, thereby achieving a porosity of the metal dense layer 11 that is less than the porosity of the metal adjacent layer 13. Exemplarily, the temperature of the hot deformation forging is 200° C. to 300° C. After the metal casting 110 is subjected to hot deformation forging, the deformation amount of the metal dense layer 11 relative to the surface layer 124 in the thickness direction is ΔW, and ΔW is 0.3mm to 0.5mm. That is, the deformation amount of the metal substrate 10 relative to the metal casting 110 in the thickness direction of the surface layer 124 is ΔW of 0.3mm to 0.5mm. In this embodiment, the outer surface of the metal casting 110 includes a surface to be treated. During the hot deformation forging process, the metal casting 110 squeezes the surface to be treated so that the surface layer 124 is formed into a metal hot deformation layer 126 through hot deformation forging. The surface to be treated of the metal casting 110 is formed into the appearance surface 101 of the metal substrate 10. For example, before the hot deformation forging, the thickness of the metal outer layer 12 of the metal casting 110 can be 0.5mm to 1.0mm, that is, the thickness of the portion of the metal casting 110 close to the surface to be treated is 0.5mm to 1.0mm. The metal thermal deformation layer 126 includes a metal dense layer 11 and a metal surplus layer 17 . The metal dense layer 11 is connected between the metal adjacent layer 13 and the metal surplus layer 17 . The metal surplus layer 17 is located outside the metal dense layer 11 .

[0052] 7 , which is a schematic diagram illustrating the changes in the metal casting 110 shown in FIG6 after hot deformation and forging, in which the metal residual layer 17 is removed and the appearance layer 30 is prepared.

[0053] S3. Remove the excess metal layer 17 to obtain the housing 300. In this embodiment, CNC (Computerized Numerical Control) processing is used to remove the excess metal layer 17 in the metal thermal deformation layer 126 along the thickness direction of the metal thermal deformation layer 126. Exemplarily, the thickness of the excess metal layer 17 is ΔH, and ΔH is 0.3 mm to 0.5 mm. After removing the excess metal layer 17, the thickness of the metal dense layer 11 is D. By removing the excess metal layer 17, the outer surface of the metal substrate 10 is facilitated to achieve the appearance of being free of holes 103, thereby 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.

[0054] S4. Prepare an appearance layer 30 on the outer surface of the metal dense layer 11. Exemplarily, the appearance layer 30 can be prepared by spraying or physical vapor deposition (PVD). In this embodiment, before step S4, the outer surface of the metal dense layer 11 is also polished to remove the knife marks on the outer surface of the metal dense 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 metal dense layer 11 of the metal substrate 10, while also improving the corrosion resistance and aesthetics of the metal substrate 10.

[0055] The shell 300 prepared in the embodiment of the present application was used as a simulation sample. After simulation, the shell 300 was found to have the reliability requirements in terms of anti-bending and anti-drop.

[0056] Currently, the metal casting 110 is mainly produced by CNC (Computerized Numerical Control) processing, which takes a long time and has high processing costs. The embodiment of the present application provides a method for producing a housing 300, which uses a casting method to produce the metal casting 110. Compared with the method of producing the metal casting 110 by CNC processing, the casting time is shortened and the cost is lower.

[0057] Furthermore, after casting, the metal casting 110 will form holes 103 on its outer surface, which will affect the appearance of the metal casting 110 and, in turn, the appearance of the housing 300. Conventional processes for producing the housing 300 using the metal casting 110 require first CNC machining the metal casting 110, then polishing the outer surface of the metal casting 110. The holes 103 on the outer surface of the metal casting 110 are then filled with a filling material using a puttying process. The filling material is then baked to solidify, and the outer surface of the metal casting 110 is then polished again. The above steps of puttying, baking, and polishing are repeated until the appearance of the metal casting 110 meets the requirements. Finally, an exterior coating 30 is applied to the outer surface of the metal casting 110 to form the housing 300. After removing the surface appearance layer 30 of the shell 300 prepared in this way, the metal casting 110 is exposed. The crystal structure of the metal casting 110 is exposed by HF acid corrosion. The position of the filler can be clearly observed on the surface of the metal casting 110, and there is a clear boundary between the position of the filler and the position without filler. The surface consistency of the shell 300 is poor, the appearance is uneven, the manufacturing process is long, the appearance requires multiple polishing, filler and baking, the yield is low, and the preparation cost is high.

[0058] The method for preparing the housing 300 provided in the embodiment of the present application is to perform hot deformation forging on the portion of the metal outer layer 12 of the metal casting 110 that is away from the metal substrate 15. By means of heat deformation, the material in the portion of the metal outer layer 12 of the metal casting 110 that is away from the metal substrate 15 undergoes micro-flow, that is, the portion of the metal casting 110 near the outer surface undergoes micro-flow. After the flow, the structure of the portion of the metal outer layer 12 that is away from the metal substrate 15 becomes uniform, and a metal dense layer 11 is formed. At this time, during the hot deformation forging process, the outer surface of the metal casting 110 and some of the pores 103 in the metal outer layer 12 are closed, so that the pores 103 on the outer surface of the prepared metal dense layer 11 are closed. The porosity of the prepared metal dense layer 11 is low, which is beneficial to improving the appearance of the prepared metal substrate 10, and further beneficial to improving the appearance of the housing 300. In the method for preparing the shell 300 provided in the embodiment of the present application, the holes 103 of the dense metal layer 11 formed by hot deformation and forging are closed, and the prepared shell 300 does not require a filling process, which improves the surface consistency of the metal substrate 10, thereby facilitating the improvement of the surface consistency of the shell 300. At the same time, compared with the above-mentioned traditional process, multiple filling and polishing steps are eliminated, resulting in a simple manufacturing process and low cost. In addition, by forming the dense metal layer 11 by hot deformation and forging the portion of the metal outer layer 12 that is away from the metal base 15, the structural strength of the metal substrate 10 can be improved, thereby facilitating the improvement of the structural strength of the shell 300.

[0059] In addition, compared with the method in which the appearance layer 30 is directly attached to the outer surface of the metal casting 110, the part of the metal outer layer 12 of the metal casting 110 in the embodiment of the present application that is away from the metal base 15 is extruded to form a metal dense layer 11. A more stable gripping force can be formed between the metal dense layer 11 and the appearance layer 30, and the metal dense layer 11 can exhibit better wear resistance and resistance to the appearance layer 30 falling off, which is beneficial to improving the bonding ability between the metal substrate 10 and the appearance layer 30, thereby helping to improve the appearance effect of the shell 300.

[0060] The above disclosure is only a preferred embodiment of the present application, and it is certainly not intended to limit the scope of the rights of the present application. A person skilled in the art can understand that all or part of the processes of the above embodiments and equivalent changes made in accordance with the claims of the present application are still within the scope of the present application.

Claims

1. A method for preparing a shell, characterized in that: The method for preparing the shell comprises: A metal casting is provided, the metal casting comprising a metal matrix and a metal outer layer, the metal outer layer is located outside the metal matrix and is adjacent to the metal matrix, and holes are formed in the metal outer layer; The portion of the metal outer layer that is away from the metal substrate is subjected to hot deformation forging to obtain a dense metal layer.

2. The method for preparing a shell according to claim 1, characterized in that: 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 comprises: Performing hot deformation forging on the portion of the metal outer layer away from the metal substrate to obtain a metal hot deformation layer, wherein the metal hot deformation layer includes a metal dense layer and a metal surplus layer, and the metal surplus layer is located outside the metal dense layer; The metal surplus layer is removed to obtain the shell.

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

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

5. The method for preparing a shell according to any one of claims 1 to 3, characterized in that: The temperature of the hot deformation forging is 200°C to 300°C.

6. A housing, characterized in that: The shell includes a metal substrate, a metal dense layer and a metal adjacent layer. The metal dense layer is located on the outside of the metal substrate and is spaced apart from the metal substrate. The metal adjacent layer is fixedly connected between the metal substrate and the metal dense layer. Holes are formed in both the metal dense layer and the metal adjacent layer. The porosity of the metal dense layer is smaller than the porosity of the metal adjacent layer.

7. The housing according to claim 6, characterized in that: The porosity of the metal dense layer is ≤5%.

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

9. The housing according to claim 6, characterized in that The thickness of the metal dense layer is D, and D is 0.3 mm to 0.5 mm.

10. The housing according to any one of claims 6 to 9, characterized in that: The shell further comprises an appearance layer, and the appearance layer is arranged on the outer surface of the metal dense layer.

11. An electronic device, characterized in that: It comprises a functional module and a shell as described in any one of claims 6 to 10, wherein the functional module is installed in the shell.

12. The electronic device according to claim 11, characterized in that: The shell is a middle frame, and the electronic device further comprises a back cover, which is mounted on the middle frame.

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