阅读说明：本技术 电子设备的工件、制备方法、壳体以及电子设备 (Workpiece of electronic equipment, preparation method, shell and electronic equipment ) 是由 李威 乔艳党 岳永保 伊藤紀行 朱旭 李庆孟 于 2019-09-25 设计创作，主要内容包括：本申请实施例提供一种电子设备的工件及其制备方法。该工件可以应用在电子设备的壳体中,例如手机的盖板或者中框等。该工件为铝合金材料,所述工件表面具有至少一个纹理区域,所述纹理区域中均匀分布有多个肉眼可见的纹理版块,每一个所述纹理版块对应一个铝合金晶粒,相邻的所述纹理版块颜色深浅或者光泽度不同,从而形成“迷彩”纹理。这样的工件表面可以形成一种新的外观纹理,避免工件或采用该工件的电子设备的外观在视觉效果上过于单一。(The embodiment of the application provides a workpiece of electronic equipment and a preparation method thereof. The workpiece can be applied to a shell of electronic equipment, such as a cover plate or a middle frame of a mobile phone. The workpiece is made of aluminum alloy, the surface of the workpiece is provided with at least one texture area, a plurality of texture plates visible to naked eyes are uniformly distributed in the texture area, each texture plate corresponds to one aluminum alloy crystal grain, and the adjacent texture plates are different in color depth or glossiness, so that camouflage textures are formed. The surface of the workpiece can form a new appearance texture, and the appearance of the workpiece or an electronic device adopting the workpiece is prevented from being too single in visual effect.)

1. A method of making a workpiece for an electronic device, comprising:

Carrying out deformation processing on the aluminum alloy blank to obtain a first aluminum profile;

Carrying out heat treatment on the first aluminum profile to obtain a second aluminum profile, wherein aluminum alloy crystal grains are visible to naked eyes and are uniformly distributed in at least one preset block of the second aluminum profile;

Etching the surface of at least one preset block of the second aluminum profile by using a strong acid solution to obtain an etched piece;

And carrying out anodic oxidation treatment on the etched piece to obtain the electronic equipment workpiece.

2. The method according to claim 1, wherein the step of deforming the aluminum alloy blank to obtain the first aluminum profile comprises:

Carrying out reverse extrusion on the aluminum alloy blank to obtain a first aluminum profile; wherein the deformation of the aluminum alloy blank is 7-15%.

3. The method of claim 2, wherein the aluminum alloy billet is at a temperature of 380-550 ℃ while being counter-extruded; the temperature of the backward extrusion die is 350-550 ℃; the backward extrusion speed is more than 2 mm/s; the extrusion ratio is 30 or more.

4. The method of claim 2, wherein the step of deforming the aluminum alloy blank to obtain the first aluminum profile comprises:

Carrying out reverse extrusion on the aluminum alloy blank to obtain an aluminum extruded blank;

Forging and pressing at least one preset block of the aluminum extruded blank to obtain a first aluminum profile; the accumulated deformation of at least one preset block of the aluminum extruded blank is 7-15%, and the at least one preset block of the aluminum extruded blank corresponds to the at least one preset block of the second aluminum profile.

5. The method of claim 4, wherein the forging temperature is room temperature or 200-450 ℃ when forging the at least one predetermined section of the aluminum extrusion blank; wherein the deformation of the forging at room temperature is less than the deformation of the forging at 200-450 ℃.

6. The method according to any one of claims 1 to 5, wherein the heat treatment comprises preheating, warming, holding and cooling, wherein the preheating temperature T1 is 80-250 ℃ and the preheating time T1 is 0.2-5 hours.

7. The method of claim 6,

The temperature T2 of the temperature rise is 420-620 ℃, and the time T2 of the temperature rise is 1-8 hours;

The heat preservation temperature T2 is 420-620 ℃, and the heat preservation time T3 is 1-8 hours.

8. A method according to any one of claims 1 to 7, characterized in that in at least one predetermined block of the second aluminium profile, more than 90% of the aluminium alloy grains have a size of 0.5mm or more.

9. The method according to any one of claims 1 to 8, wherein the size of the aluminum alloy grains is 20mm or less in at least one predetermined block of the second aluminum profile.

10. The method of any one of claims 1-9, wherein the aluminum alloy grains with grain size greater than or equal to 0.5mm in the predetermined sub-block account for more than 90% of all the aluminum alloy grains in the predetermined sub-block, and wherein the predetermined sub-block is any one of the texture regions of the workpiece with area of 25mm²The continuous region of (a) corresponds to a block in the second aluminum alloy.

11. The method according to any one of claims 1 to 10, wherein the temperature of the etching is 0 to 80 ℃ and the time of the etching is 3 to 600 s; and/or the presence of a gas in the gas,

The strong acid solution comprises one or more of aqua regia, hydrofluoric acid and nitric acid.

12. the method according to any one of claims 1-11, wherein the step of heat treating the first aluminum profile to obtain a second aluminum profile further comprises:

And manufacturing the second aluminum profile into the shape of a preset electronic product workpiece.

13. The method of claim 12, further comprising, after the step of shaping the second aluminum profile into a predetermined electronic workpiece shape:

And carrying out surface mechanical treatment on the second aluminum profile which is manufactured into the shape of the preset electronic product workpiece.

14. The utility model provides an electronic equipment's work piece, the work piece is aluminum alloy material, its characterized in that, the work piece surface has at least one texture region, evenly distributed has a plurality of macroscopic texture plates in the texture region, each texture plate corresponds an aluminum alloy crystalline grain, and is adjacent texture plate colour depth or glossiness are different.

15. The workpiece according to claim 14, characterised in that in the textured area the area of a texture block with a size of 0.5mm or more accounts for more than 90% of the area of the textured area.

16. The workpiece according to claim 14 or 15, characterised in that the size of the texture block is ≤ 20 mm.

17. A workpiece according to any one of claims 14-16, characterised in that in a first area the area of texture patches with a size of 0.5mm or more, is more than 90% of the area of the first area, wherein the first area is any one of the texture areas with an area of 25mm²A continuous region of (a).

18. The utility model provides a casing of electronic equipment, its characterized in that, the casing includes center or the apron that aluminium alloy material made, the center or the apron surface has at least one texture region, evenly distributed has a plurality of macroscopic texture plates in the texture region, each the texture plate corresponds an aluminum alloy crystalline grain, and is adjacent texture plate colour depth or glossiness are different.

19. the housing of claim 18, wherein a decorative piece or an accessory is further disposed on the housing.

20. The electronic equipment is characterized in that a shell of the electronic equipment comprises a middle frame or a cover plate made of an aluminum alloy material, at least one texture area is arranged on the surface of the middle frame or the cover plate, a plurality of texture sections visible to naked eyes are uniformly distributed in the texture area, each texture section corresponds to one aluminum alloy crystal grain, and the adjacent texture sections are different in color depth or glossiness.

21. The electronic device of claim 20, wherein the area of the texture region of the texture tile with size greater than or equal to 0.5mm accounts for more than 90% of the area of the texture region.

22. the electronic device of any of claims 20-21, wherein the texture volume has a size of 20mm or less.

23. The electronic device according to any of claims 20-22, wherein the area of a texture tile with a size of 0.5mm or more in a first region is more than 90% of the area of the first region, wherein the first region is any one of the texture regions with an area of 25mm²a continuous region of (a).

Technical Field

The application relates to the technical field of material surface treatment, in particular to a workpiece of electronic equipment, a preparation method of the workpiece of the electronic equipment and the electronic equipment.

Background

In the field of electronic products (such as mobile phones, etc.), the appearance of the product becomes one of the important factors for determining whether a consumer can purchase the electronic product. The electronic product shell prepared by adopting the aluminum alloy material can realize the appearance effect by adopting the processes of sand blasting, anodic oxidation, wire drawing, anodic oxidation, polishing and anodic oxidation.

First, an aluminum alloy material is extruded to obtain an aluminum profile. And then, carrying out heat treatment on the aluminum profile, thereby improving the processing performance, the mechanical property and the like of the aluminum profile. And processing the aluminum profile subjected to heat treatment into a shape of a pre-designed workpiece by using a numerical control machine. And finally, performing sand blasting, wire drawing or bright polishing and other treatments on part or all of the surface of the processed workpiece, and performing anodic oxidation treatment to obtain the workpiece with the appearance effects of matte, wire drawing or mirror surface and the like.

These appearance effects have been applied to electronic products for many years, and are relatively single in overall vision, causing aesthetic fatigue of consumers. Therefore, how to develop a workpiece with new appearance effect for electronic products is a problem to be solved urgently by those skilled in the art.

Disclosure of Invention

The application provides a workpiece of electronic equipment and a preparation method, by which at least one texture region can be formed on the surface of the workpiece, and camouflage textures can be formed in the texture region, so that the surface of the workpiece has a new appearance effect.

In a first aspect, the application provides a workpiece of an electronic device, the workpiece is an aluminum alloy material, the surface of the workpiece has at least one texture area, a plurality of macroscopic texture sections are uniformly distributed in the texture area, each texture section corresponds to an aluminum alloy crystal grain, and is adjacent to the texture section with different color depth or different glossiness.

By adopting the implementation mode, each texture plate block in the texture area corresponds to one aluminum alloy crystal grain, the aluminum alloy crystal grain has larger size and is visible to naked eyes, and the texture area is uniformly distributed, so that a plurality of texture plate blocks which are visible to naked eyes and are uniformly distributed are formed in the texture area. The adjacent texture plates have different colors or different gloss degrees, so that the boundary between the adjacent texture plates, namely the grain boundary, is highlighted, and the texture area forms a special grain boundary texture effect, namely a camouflage texture. The workpiece with the camouflage texture is novel in appearance and is helpful for improving the attractiveness of consumers.

With reference to the first aspect, in a first possible implementation manner of the first aspect, in the texture region, an area of a texture tile with a size greater than or equal to 0.5mm accounts for more than 90% of an area of the texture region. When the condition is met, the texture blocks on the surface of the workpiece can be observed easily by normal naked eyes, and the attraction of consumers is improved.

With reference to the first aspect and the foregoing possible implementation manners, in a second possible implementation manner of the first aspect, the size of the texture section is less than or equal to 20 mm. And controlling the upper limit of the size of the texture plate block, which is equivalent to controlling the upper limit of the size of the aluminum alloy crystal grains on the surface of the workpiece. By the mode, the problems that the influence on other performances of the workpiece such as hand-holding comfort and the like due to overlarge aluminum alloy grains or the appearance of the workpiece cannot meet the design requirement can be avoided.

With reference to the first aspect and the foregoing possible implementation manners, in a third possible implementation manner of the first aspect, in a first region, an area of a texture block with a size greater than or equal to 0.5mm accounts for more than 90% of an area of the first region, where the first region is any one of the texture regions with an area of 25mm²A continuous region of (a). By controlling the above conditions, it can be ensured that the texture patches in the texture region have better uniformity.

in a second aspect, the present application provides a method of preparing a workpiece, comprising: carrying out deformation processing on the aluminum alloy blank to obtain a first aluminum profile; carrying out heat treatment on the first aluminum profile to obtain a second aluminum profile, wherein aluminum alloy crystal grains are visible to naked eyes and are uniformly distributed in at least one preset block of the second aluminum profile; etching the surface of at least one preset block of the second aluminum profile by using a strong acid solution to obtain an etched piece; and carrying out anodic oxidation treatment on the etched piece to obtain the electronic equipment workpiece.

By adopting the realization mode, through deformation processing and heat treatment processes, macroscopic aluminum alloy grains which are uniformly distributed are formed on the whole or part of the surface of the aluminum alloy workpiece. And etching the surface of the workpiece to improve the contrast between different grains on the surface of the workpiece, so that the grain boundary between the aluminum alloy grains is highlighted. By adopting the method, the surface of the workpiece can be locally or integrally formed with the camouflage texture, thereby generating a novel appearance effect. The method has simple process and is suitable for industrial production.

With reference to the second aspect, in a first possible implementation manner of the second aspect, the step of performing deformation processing on the aluminum alloy blank to obtain the first aluminum profile includes: carrying out reverse extrusion on the aluminum alloy blank to obtain a first aluminum profile; wherein the deformation of the aluminum alloy blank is 7-15%. The deformation amount of the aluminum alloy blank is controlled to 7-15% by a reverse extrusion process, which is beneficial to forming macroscopic aluminum alloy grains which are uniformly distributed in the whole workpiece.

with reference to the second aspect and the foregoing possible implementation manners, in a second possible implementation manner of the second aspect, when the aluminum alloy billet is subjected to backward extrusion, the temperature of the aluminum alloy billet is 380 to 550 ℃; the temperature of the backward extrusion die is 350-550 ℃; the backward extrusion speed is more than 2 mm/s; the extrusion ratio is 30 or more. The higher the temperature of the aluminum alloy blank and the die is, the parameters such as the extrusion ratio, the extrusion speed and the like are controlled within the range, so that the deformation of the aluminum alloy blank is favorably controlled, and further, the aluminum alloy crystal grains which are visible to naked eyes and are uniformly distributed are favorably formed.

With reference to the second aspect and the foregoing possible implementation manners, in a third possible implementation manner of the second aspect, the step of performing deformation processing on the aluminum alloy blank to obtain the first aluminum profile includes: carrying out reverse extrusion on the aluminum alloy blank to obtain an aluminum extruded blank; forging and pressing at least one preset block of the aluminum extruded blank to obtain a first aluminum profile; the accumulated deformation of at least one preset block of the aluminum extruded blank is 7-15%, and the at least one preset block of the aluminum extruded blank corresponds to the at least one preset block of the second aluminum profile. By adopting the realization mode, the local or whole deformation accumulation of the aluminum alloy blank can reach 7-15%, which is beneficial to forming macroscopic aluminum alloy crystal grains on the local or whole part of the workpiece and forming camouflage textures on the local or whole surface of the workpiece.

With reference to the second aspect and the foregoing possible implementation manners, in a fourth possible implementation manner of the second aspect, when forging at least one preset block of the aluminum extruded blank, the forging temperature is room temperature or 200 to 450 ℃; wherein the deformation of the forging at room temperature is less than the deformation of the forging at 200-450 ℃. The forging temperature and other parameters are controlled within the range, so that the local or overall deformation of the aluminum alloy blank can be controlled, and macroscopic and uniformly distributed aluminum alloy grains can be formed on the local or overall workpiece.

With reference to the second aspect and the foregoing possible implementation manners, in a fifth possible implementation manner of the second aspect, the heat treatment includes preheating, temperature rising, heat preservation, and cooling, where the preheating temperature T1 is 80-250 ℃, and the preheating time T1 is 0.2-5 hours. By adding the preheating stage, the energy of the position with relatively high energy in the first aluminum profile can be reduced, so that the difference between the position with relatively high energy and the position with relatively low energy is eliminated or reduced, and further, the preparation for generating more uniform coarse crystals is provided.

With reference to the second aspect and the foregoing possible implementation manners, in a sixth possible implementation manner of the second aspect, the temperature T2 of the temperature rise is 420 to 620 ℃, and the time T2 of the temperature rise is 1 to 8 hours; the heat preservation temperature T2 is 420-620 ℃, and the heat preservation time T3 is 1-8 hours. The temperature and time for heating and heat preservation are controlled within the range, so that macroscopic aluminum alloy crystal grains can be formed.

With reference to the second aspect and the foregoing possible implementation manners, in a seventh possible implementation manner of the second aspect, in at least one preset block of the second aluminum profile, the size of more than 90% of aluminum alloy grains is greater than or equal to 0.5 mm. When the condition is met, the texture block on the surface of the finally manufactured workpiece can be observed easily by normal naked eyes, and the attraction to consumers is improved.

With reference to the second aspect and the foregoing possible implementation manners, in an eighth possible implementation manner of the second aspect, in at least one preset block of the second aluminum profile, the size of the aluminum alloy crystal grain is less than or equal to 20 mm. The upper limit of the size of the aluminum alloy crystal grains on the surface of the workpiece is controlled, so that the problems that the handling comfort and other performances of the workpiece are influenced due to the overlarge aluminum alloy crystal grains or the appearance of the workpiece cannot meet the design requirement can be solved.

With reference to the second aspect and the foregoing possible implementation manners, in a ninth possible implementation manner of the second aspect, in the preset sub-block, the aluminum alloy crystal grains with the grain size not less than 0.5mm account for more than 90% of all the aluminum alloy crystal grains in the preset sub-block, where the preset sub-block is any texture area of the workpiece, and the area of any texture area of the preset sub-block is 25mm²The continuous region of (a) corresponds to a block in the second aluminum alloy. By controlling the above conditions, it is possible to ensure that the texture patches are distributed more uniformly in the texture region of the surface of the finally manufactured workpiece.

With reference to the second aspect and the possible implementation manners described above, in a tenth possible implementation manner of the second aspect, the etching temperature is 0 to 80 ℃, and the etching time is 3 to 600 s; and/or the strong acid solution comprises one or more of aqua regia, hydrofluoric acid and nitric acid. The etching process and the reagent are beneficial to increasing the corrosion difference degree of crystal grains with different orientations, thereby being beneficial to enabling the crystal boundary between the crystal grains on the surface of the workpiece to be obvious.

With reference to the second aspect and the foregoing possible implementation manners, in an eleventh possible implementation manner of the second aspect, after the step of performing heat treatment on the first aluminum profile to obtain a second aluminum profile, the method further includes: and manufacturing the second aluminum profile into the shape of a preset electronic product workpiece. By adopting the implementation mode, the workpiece with a pre-designed shape can be manufactured, and simultaneously, the surface of the workpiece forms camouflage texture.

With reference to the second aspect and the foregoing possible implementation manners, in a twelfth possible implementation manner of the second aspect, after the step of manufacturing the second aluminum profile into a shape of a preset electronic product workpiece, the method further includes: and carrying out surface mechanical treatment on the second aluminum profile which is manufactured into the shape of the preset electronic product workpiece. By adding the step of surface mechanical treatment, the finally manufactured workpiece can obtain other appearance effects besides the camouflage texture.

The third aspect, this application provides an electronic equipment's casing, the casing includes center or the apron that aluminium alloy material made, the center or the apron surface has at least one texture region, evenly distributed has a plurality of macroscopic texture plates in the texture region, each texture plate corresponds an aluminum alloy crystalline grain, and is adjacent texture plate colour depth or glossiness are different.

With reference to the third aspect, in a first possible implementation manner of the third aspect, a decorative piece or an auxiliary material is further disposed on the housing.

With reference to the third aspect and the foregoing possible implementation manners, in a second possible implementation manner of the third aspect, in the texture region, an area of a texture tile with a size greater than or equal to 0.5mm occupies greater than or equal to 90% of an area of the texture region.

With reference to the third aspect and the foregoing possible implementation manners, in a third possible implementation manner of the third aspect, the size of the texture section is less than or equal to 20 mm.

With reference to the third aspect and the foregoing possible implementation manners, in a fourth possible implementation manner of the third aspect, in a first region, an area of a texture block with a size of greater than or equal to 0.5mm accounts for more than 90% of an area of the first region, where any one of the texture regions in the first region has an area of 25mm²A continuous region of (a).

in a fourth aspect, the present application provides an electronic device comprising any one of the housings of the third aspect.

Drawings

In order to more clearly explain the technical solution of the present application, the drawings needed to be used in the embodiments will be briefly described below.

FIG. 1 is a partial schematic view of a textured region of a workpiece surface of an electronic device of the present application;

FIG. 2 is a partial metallographic image of a textured area of a workpiece surface of an electronic device according to the present application;

FIG. 3 is a schematic flow diagram of one implementation of a workpiece preparation method of the present application;

FIG. 4 is a schematic diagram of an intermediate or finished product at various stages in a process flow for manufacturing an electronic device workpiece;

FIG. 5 is a process diagram of a recrystallization heat treatment process of a first aluminum profile;

FIG. 6 is a partial schematic view of the surface of an aluminum alloy workpiece treated by anodic oxidation only and without etching in comparative example 2 of the present application;

FIG. 7 is a partial schematic view of a grain structure image taken under a microscope while calculating the size of a texture patch on the surface of a workpiece according to an embodiment of the present application;

Fig. 8 is a schematic structural diagram of one implementation of the housing of the present application.

Description of reference numerals:

A housing 1; a middle frame 11; a cover plate 12; texture region 2; the texture section 21.

Detailed Description

According to the aluminum alloy workpiece of the industrial electronic product, after the aluminum alloy material is prepared into the workpiece, the surface of the workpiece can present appearance characteristics of light color and uniform glossiness. The inventors have analyzed that the appearance of the workpiece surface is not the same as the "camouflage" texture provided by the embodiments of the present application, but the appearance of the workpiece surface is not the same.

First, the aluminum alloy grain size in common aluminum alloy workpieces is small and difficult to distinguish visually. Generally, the smaller the size of the aluminum alloy grains, the better the mechanical properties (e.g., strength, elongation, etc.) of the aluminum profile. Therefore, in the stage of deforming the aluminum alloy blank (i.e., the aluminum alloy raw material), the manufacturer minimizes the deformation of the aluminum alloy blank, so as to form uniform and fine aluminum alloy grains (hereinafter referred to as fine grains) in the finally obtained aluminum alloy workpiece. In typical aluminum alloy workpieces, the average size of fine grains is typically 0.1mm and below, the size of the aluminum alloy grains in more than 90% of the surface of the workpiece is below 0.3mm, and only no more than 5% of the aluminum alloy grains are greater than 0.5mm in size. The average limit of resolution for the human eye is approximately 0.09mm at a distance of 25 cm. Therefore, it is very laborious for human eyes to distinguish the aluminum alloy grains on the surface of such an aluminum alloy workpiece. Therefore, the workpiece surface with uniform color shade and glossiness observed by naked eyes actually corresponds to a plurality of fine crystals which are difficult to distinguish by naked eyes for the workpiece surface which is only subjected to the conventional anodic oxidation treatment.

Second, the grain boundaries between the aluminum alloy grains are not noticeable after the conventional anodizing process. The orientation of aluminum alloy grains on the surface of a workpiece tends to be different, and grain boundaries (grain boundaries) are interfaces between grains having the same structure but different orientations. The crystal surface interfaces of the aluminum alloy crystal grains with different orientations are different on the surface of the workpiece. If the surface etching is performed in an acidic or alkaline solution, the etching rate of different grains on the surface of the workpiece is different, which results in different etching depths of the grain surface. When light irradiates on the crystal grains on the surface of the workpiece, the crystal grains with different corrosion degrees have different reflection of the light. The grains that produce mainly diffuse reflection look darker visually, and the grains that produce mainly specular reflection look lighter visually. However, in the conventional anodic oxidation process, the adopted acid solution is generally medium-strong acid, and the selective corrosion effect on different crystal grains is not obvious enough, so that the color depth difference between crystal faces of different crystal grains is small. In addition, the size of the aluminum alloy crystal grains is very small, so that when the aluminum alloy is observed by naked eyes, the crystal boundaries among all the aluminum alloy crystal grains cannot be observed, and crystal planes of a plurality of crystal grains are regarded as an integral surface with light color and uniform glossiness. Also, even in the case where the distance from the surface of the workpiece is very close, few grain boundaries on the surface of the workpiece can be observed with the naked eye, and these observable grain boundaries are not significant.

Based on the above, embodiments of the present application provide a workpiece of an electronic device and a method for manufacturing the workpiece of the electronic device. The workpiece surface has at least one textured area, wherein the textured area forms a camouflage texture, thereby providing a novel appearance effect to the workpiece surface. The appearance of the "camouflage" texture of the surface of the workpiece will be described first, followed by a description of the method of making the workpiece.

Electronic devices in the present application include, but are not limited to: a mobile phone (mobile phone), a tablet computer (Pad), a personal computer, a Virtual Reality (VR) terminal device, an Augmented Reality (AR) terminal device, a wearable device, a television, a vehicle-mounted terminal device, smart glasses, and the like.

The workpiece includes a part in an industrial processing process, and the workpiece may be a single part, or a part formed by combining several parts, and the like, which is not limited in the present application. The workpiece of the electronic device in the present application may be a part of the electronic product, which is exposed to the external environment, such as a shell of a mobile phone, a wearing structure of a wearable device, and the like. The workpiece is prepared from an aluminum alloy material.

The workpiece surface has one or more textured regions. When the entire surface of the workpiece has a "camouflage" texture, the entire surface of the workpiece may be considered a textured area. A plurality of macroscopic texture plates are uniformly distributed in the texture area, each texture plate corresponds to one aluminum alloy grain, and boundaries among the texture plates correspond to grain boundaries of the aluminum alloy grains. And the adjacent texture blocks have different colors or different glossiness.

Referring to fig. 1 and 2, fig. 1 is a partial schematic view of a textured area on a surface of a workpiece of an electronic device according to the present application; fig. 2 is a partial metallographic image of a textured region of the workpiece surface of the electronic device of the present application. It can be seen from fig. 1 that the texture region includes a plurality of texture patches that are visible to the naked eye and have a relatively uniform overall distribution. In addition, in fig. 1, the color depth or the glossiness of the adjacent texture blocks are different, and the color depth difference or the glossiness difference between the adjacent blocks is large, so that the boundaries between the different blocks, namely the grain boundaries, can be observed relatively easily by naked eyes. From the metallographic image of fig. 2, 28 texture plates can be seen, each texture plate corresponds to one aluminum alloy grain, the overall distribution of the texture plates is relatively uniform, and the color depth or the glossiness of the adjacent texture plates are different.

As previously mentioned, in conventional aluminum alloy workpieces, the average size of fine grains is typically 0.1mm or less, the size of the aluminum alloy grains in more than 90% of the surface of the workpiece is less than 0.3mm, and the size of the aluminum alloy grains in only not more than 5% of the surface is greater than 0.5 mm. In embodiments of the present application, the macroscopic texture patches may be measured using a more specific metric. That is, in the texture region, the area of the texture block with the size of more than or equal to 0.5mm accounts for more than 90% of the area of the texture region. When this condition is satisfied, the normal naked eye can more easily observe these texture patches of the workpiece surface.

Optionally, in any texture region, the size of the texture tile is ≦ 20 mm. And controlling the upper limit of the size of the texture plate block, which is equivalent to controlling the upper limit of the size of the aluminum alloy crystal grains on the surface of the workpiece. By the mode, the problems that the influence on other performances of the workpiece such as hand-holding comfort and the like due to overlarge aluminum alloy grains or the appearance of the workpiece cannot meet the design requirement can be avoided.

Similarly, the texture patches in the texture region are uniformly distributed, and a more specific index can be used for measurement. Any one of the texture regions is 25mm in area²The continuous region of (2) is referred to as a first region. And in the first area, the area of the texture block with the size being more than or equal to 0.5mm accounts for more than 90% of the area of the first area, and the distribution of the texture blocks visible to the naked eyes in the texture area is uniform.

The texture block may be in a regular shape or an irregular shape, which is not limited in the present application. Generally, because there may be differences in the orientation of the aluminum alloy grains corresponding to different texture patches, there is a corresponding difference in the shape of the different texture patches. The size of the texture patches can be measured in a conventional metrology manner. For example, when the texture tile is rectangular, the length of the rectangle may be used as its dimension. For another example, when the texture section is irregular, the distance between two points that are farthest apart on the edge of the texture section may be used as its size.

It should be noted that, in the above-described textured region, there are inevitably small regions in which the size of the aluminum alloy grains is small and difficult to distinguish with the naked eye. Of these regions, one region may correspond to one or more fine aluminum alloy grains. However, this small partial area does not significantly affect the overall appearance of the textured area of the workpiece.

in the embodiments of the present application, the shade of color refers to a difference in gradation of color. The difference in color shade between adjacent texture patches refers to the difference in gray levels that can be discerned by the normal naked eye.

Gloss represents the ability of a material surface to reflect light. When the material with smooth surface is irradiated by visible light, mirror reflection can be generated, and the reflected light directly irradiates human eyes, so that the surface of the material is glossy. The difference in glossiness between adjacent plates in the embodiment of the application refers to the difference in glossiness distinguishable by normal naked eyes.

In the texture area on the surface of the electronic device workpiece, each texture plate block corresponds to one aluminum alloy crystal grain, and because the aluminum alloy crystal grains are large in size and visible to naked eyes and are distributed uniformly in the texture area, a plurality of texture plate blocks which are visible to naked eyes and uniformly distributed are formed in the texture area. The adjacent texture plates have different colors or different gloss degrees, so that the boundary between the adjacent texture plates, namely the grain boundary is highlighted, and the texture area forms a special grain boundary texture effect, namely the camouflage texture. Workpieces having such "camouflage" textures are novel in appearance, helping to attract consumers to purchase the workpieces or electronic devices that include the workpieces.

According to the preparation method in the embodiment of the application, the whole or partial surface of the aluminum alloy workpiece forms macroscopic aluminum alloy grains which are uniformly distributed by improving the existing deformation processing and heat treatment processes; the surface of the workpiece is etched by a strong acid corrosion process, so that the contrast between different grains on the surface of the workpiece is improved, and the grain boundary between aluminum alloy grains is highlighted. By adopting the method, the surface of the workpiece can be locally or integrally formed with the camouflage texture, thereby generating a novel appearance effect.

Referring to fig. 3, fig. 3 is a schematic flow chart of one implementation manner of the workpiece preparation method of the present application. The method may include the following steps S100 to S600.

S100: and carrying out deformation processing on the aluminum alloy blank to obtain a first aluminum profile.

As the aluminum alloy material in the embodiment of the present application, a conventional aluminum alloy material, for example, 6-series aluminum alloy, 5-series aluminum alloy, 2-series aluminum alloy, 7-series aluminum alloy, or the like can be used.

In the aluminum alloy processing process, generally, an aluminum alloy material is first subjected to deformation processing to be formed, so that an aluminum profile is obtained. The aluminum alloy grains which are visible to the naked eye and uniformly distributed can be formed in the aluminum profile through the deformation processing and the subsequent heat treatment steps, so that the control of the deformation amount during the deformation processing is very important. The implementation of two possible deformation processes, extrusion, and extrusion + forging, will be described separately below.

The main process of extrusion comprises: firstly, manufacturing a mould according to the design of an aluminum profile; then, the heated aluminum alloy material is extruded from the die by an extruder to obtain an aluminum profile. In a general method for preparing the aluminum profile, a forward extrusion mode is generally adopted, namely, the aluminum profile flows out in the same direction as the movement direction of an extrusion shaft of an extruder during extrusion. As described above, in order to improve the mechanical properties of the aluminum profile, the deformation amount of the aluminum alloy material is generally reduced as much as possible so as to form fine aluminum alloy crystal grains in the extrusion molding step.

In one implementation of the deformation process of the present application, a reverse extrusion mode may be adopted, that is, the aluminum profile outflow direction is opposite to the movement direction of the extrusion shaft of the extruder during extrusion. And carrying out reverse extrusion on the aluminum alloy blank to obtain the first aluminum profile. By the mode, the integral deformation of the aluminum alloy blank can reach 7-15%, and the aluminum alloy blank is beneficial to forming macroscopic aluminum alloy grains which are uniformly distributed in the whole workpiece.

In the backward extrusion of the aluminum alloy billet, the temperature of the aluminum alloy billet is optionally 380-550 ℃. Optionally, the temperature of the counter extrusion die is 350-550 ℃. Alternatively, the backward extrusion speed is 2mm/s or more and the extrusion ratio is 30 or more. The higher the temperature of the aluminum alloy blank and the die is, the higher the extrusion ratio and the extrusion speed have certain influence on the deformation of the aluminum alloy blank, and the parameters are controlled within the range, so that the deformation of the aluminum alloy blank can be controlled, and the aluminum alloy crystal grains which are visible to naked eyes and are uniformly distributed can be formed.

In another implementation manner of the deformation processing, the aluminum alloy blank can be initially extruded in a reverse extrusion manner to obtain an aluminum extruded blank. And then forging and pressing at least one preset block of the aluminum extruded blank in a forging and pressing mode to obtain the first aluminum profile. In the embodiment of the application, the preset block of the aluminum extruded blank just corresponds to the texture area of the surface of the workpiece after the workpiece is prepared. The predetermined block may be a part of the aluminum extruded blank or the whole aluminum extruded blank, which is not limited in the present application.

by the mode, the local or overall deformation of the aluminum alloy blank can be accumulated to 7-15%, macroscopic uniformly distributed aluminum alloy crystal grains can be locally or integrally formed on the workpiece, and local or overall surface of the workpiece can form camouflage texture.

Optionally, the forging method can be used for enabling the deformation of at least one preset area of the aluminum extruded blank to reach 5% -15%, so that the accumulated deformation of the preset areas reaches 7-15%.

Optionally, when forging at least one predetermined section of the aluminum extrusion blank, the forging temperature may be room temperature or 200-450 ℃. The room temperature is an atmospheric ambient temperature, and may be any temperature of-25 to 40 ℃, for example, 25 ℃. When forging at room temperature, the amount of forging deformation is relatively small, preferably 5% to 10%. The forging deformation is relatively large, preferably 10-15%, when forging at 200-450 ℃.

It should be noted that the process conditions of the backward extrusion may refer to the process conditions described above, but the amount of deformation achieved by the backward extrusion needs to be slightly lower than that described above, so as to achieve the cumulative amount of deformation of the predetermined block after forging to 7-15%. For example, in the simple backward extrusion method, the deformation of the aluminum alloy billet needs to be 12%. Then, by adopting the extruding and forging method, the deformation of the aluminum alloy blank can reach 6% to obtain the aluminum extruded blank, and then the deformation of one or more preset blocks of the aluminum extruded blank reaches 6% by adopting the forging method, so that the accumulated deformation of the preset blocks reaches 12%, and the deformation of other blocks except the preset blocks in the aluminum extruded blank is still maintained at 6%.

S200: and carrying out heat treatment on the first aluminum profile to obtain a second aluminum profile.

Through heat treatment, the interior of the first aluminum profile subjected to deformation processing can be recrystallized, so that macroscopic and uniformly distributed coarse crystals are formed in the preset blocks of the second aluminum profile. It should be noted that the preset blocks of the second aluminum profile correspond to the preset blocks of the aluminum extruded blank, and after the workpiece is prepared, the preset blocks of the second aluminum profile correspond to the texture areas of the surface of the workpiece, so that the camouflage texture is formed in the texture areas of the workpiece.

As previously mentioned, in typical aluminum alloy workpieces, the average size of fine grains is typically 0.1mm and below, the size of the aluminum alloy grains in more than 90% of the area of the workpiece surface is below 0.3mm, and only not more than 5% of the aluminum alloy grains are greater than 0.5mm in size. In the embodiment of the present application, the macroscopic coarse grains formed in the predetermined area of the second aluminum profile can also be measured by using a more specific index. Namely, in the preset block of the second aluminum profile, the size of more than 90% of aluminum alloy crystal grains is more than or equal to 0.5 mm. Thus, when such second aluminum profiles are prepared into a workpiece, the aluminum alloy crystal grains on the surface of the workpiece corresponding to the preset blocks of the second aluminum profiles can be relatively easily observed by naked eyes.

Optionally, in the preset blocks of the second aluminum profile, the size of the aluminum alloy crystal grains is less than or equal to 20 mm. By controlling the upper limit of the size of the aluminum alloy crystal grains, the problem that the aluminum alloy crystal grains are too large, other performances such as hand-holding comfort and the like of a workpiece are influenced, or the appearance of the workpiece cannot meet the design requirement can be avoided.

Similarly, coarse crystals with uniform distribution can also be measured by using a more specific index. After the workpiece is prepared, the preset blocks of the second aluminum profile just correspond to texture areas of the surface of the workpiece, and any one area in the texture areas is 25mm²the blocks in the second aluminum profile corresponding to the continuous areas in the present embodiment may be referred to as preset sub-blocks. In the preset sub-block, the aluminum alloy crystal grains with the grain size of more than or equal to 0.5mm account for more than 90% of all the aluminum alloy crystal grains in the preset sub-block.

A typical heat treatment may include three stages of temperature rise, holding and cooling. In the embodiment of the present application, in order to further improve the uniformity of the formed coarse crystals, a stage of preheating is added before the temperature rise.

At the stage of the deformation process, there may be a difference in the amount of deformation at different locations in the aluminum alloy blank, i.e., non-uniform deformation. For example, the deformation processing aims to make the deformation amount of the aluminum alloy material 12%, but after the actual processing, the deformation amount of the aluminum alloy material is 11% at some positions and 13% at some positions, which are greatly different. At this time, if the temperature is raised to the holding temperature directly in the temperature raising stage, the energy at some positions in the first aluminum profile is relatively high, and the energy at other positions is relatively low. This results in a second aluminium profile with relatively poor homogeneity of the coarse crystals, since the grains tend to grow more at higher energies.

For this reason, in the embodiment of the present application, by increasing the stage of preheating, the energy of the position with relatively high energy in the first aluminum profile can be reduced to some extent, so as to eliminate or reduce the difference between the position with relatively high energy and the position with relatively low energy, thereby preparing for generating more uniform coarse crystals.

Referring to fig. 5, fig. 5 is a diagram of a recrystallization heat treatment process of the first aluminum profile. As can be seen from fig. 5, the heat treatment in the embodiment of the present application includes four stages of preheating, temperature raising, temperature holding, and cooling. Firstly, entering a preheating stage, wherein the preheating temperature is T1, and the preheating time is T1. And then entering a temperature rising stage, rising the temperature from T1 to T2, and rising the temperature for T2. Then, the temperature is maintained at T2 for a time T3. Finally, entering a cooling stage, and cooling the temperature to room temperature within t4 time.

Alternatively, the preheating temperature T1 is 80-250 ℃ and the preheating time T1 is 0.2-5 hours.

Optionally, the temperature T2 of the temperature rise is 420-620 ℃, and the time T2 of the temperature rise is 1-8 hours. By properly prolonging the temperature rise time, the difference of the deformation amount of different positions of the first aluminum profile can be relieved to a certain extent.

optionally, the holding temperature T2 is 420-620 ℃ and the holding time T3 is 1-8 hours. If the alloy content in the first aluminum profile is low, the holding temperature can be adjusted to be lower within the range. Conversely, if the alloy content in the first aluminum profile is high, the holding temperature can be adjusted higher within this range.

Alternatively, the cooling may be performed by various cooling methods such as furnace cooling, air cooling, and water cooling. When different aluminum alloy blanks are adopted, different cooling modes can be properly adjusted. For example, in the case of 6-series aluminum alloy, in order to obtain high strength of the workpiece, the second aluminum profile in a solid solution state can be obtained by quenching with water cooling. Subsequently, the processes of flattening and aging heat treatment of the plate can be added to obtain the second aluminum profile with good flatness in an aging strengthening state.

S300: and manufacturing the second aluminum profile into the shape of a preset electronic product workpiece.

The shapes of electronic product workpieces to be manufactured, such as a middle frame and a rear cover of a mobile phone, are designed in advance. Then, the second aluminum profile is fabricated into the shape of the designed electronic product workpiece by a conventional processing method, for example, a Computer Numerical Control (CNC), a press forging + CNC, a decorative strip, a frame + middle plate detaching member, and the like.

Referring to fig. 4, fig. 4 is a schematic structural diagram of an intermediate product or a finished product at different stages in a process flow for manufacturing a workpiece of an electronic device. Fig. 4A is a schematic structural diagram of a second aluminum profile obtained by performing deformation processing and heat treatment on an aluminum alloy blank. It can be seen from fig. 4A that the surface of the second aluminum profile has formed uniformly distributed, macroscopic macrocrystals. Fig. 4B is a schematic structural view of the middle frame of the mobile phone manufactured by processing the second aluminum profile. The outer side surface of the mobile phone middle frame is provided with coarse grains which are uniformly distributed and visible to naked eyes, but the boundaries between texture plates corresponding to adjacent grains, namely grain boundaries, are not obvious enough, and can be further highlighted after a subsequent etching step.

S400: and carrying out surface mechanical treatment on the second aluminum profile which is manufactured into the shape of the preset electronic product workpiece.

in addition to providing the workpiece of the electronic device with "camouflage" texture, a surface mechanical treatment step may be added before the etching step in order to obtain other appearance effects. The surface mechanical treatment can adopt the existing process, including one or more of polishing and sand blasting, for example, polishing, sand blasting, polishing + sand blasting, etc., so as to obtain the effects of high gloss, matte, high matte, etc. on the surface of the workpiece at the same time.

in the present invention, the steps S300 and S400 are not essential steps, but optional steps, and may be selected according to the difference of the workpieces and the appearance effect of the workpieces.

S500: and etching the surface of at least one preset block of the second aluminum profile by using a strong acid solution to obtain the etched piece.

Macroscopic aluminum alloy crystal grains are uniformly distributed on the surface of at least one preset block of the second aluminum profile, the orientations of the aluminum alloy crystal grains are different, and crystal plane interfaces of the aluminum alloy crystal grains with different orientations are different. In the etching process, the interface energy is different, under the same etching condition, the corrosion rates of crystal faces of different crystal grains are different, crystal faces and crystal boundaries of certain crystal grains are corroded faster, and crystal faces of other crystal grains are corroded slower. This is the principle of the selective corrosion action of the strong acid solution on the aluminum alloy grains and grain boundaries.

The corrosion difference degree of the crystal grains with different orientations is increased by the selective corrosion action of the strong acid solution. Therefore, when light is irradiated on the crystal grains on the surface of the workpiece, the crystal grains mainly generating diffuse reflection look darker visually and the crystal grains mainly generating specular reflection look lighter visually, as compared with the surface of the workpiece after the simple conventional anodizing treatment. Visually, the selective etching action by the strong acid increases the difference in color depth between adjacent grains, and/or the difference in glossiness. Due to the fact that the color depth difference and/or the glossiness difference between the adjacent crystal grains are increased, and the crystal grains reach the level visible to the naked eye, the grain boundaries among the crystal grains on the surface of the workpiece are highlighted, and the grain boundaries and different texture blocks can be observed more easily by the naked eye.

Please refer to fig. 4, wherein fig. 4C is a schematic structural diagram of the second aluminum profile after being etched, which is fabricated into the middle frame of the mobile phone. In fig. 4C, it can be seen that the whole outer surface of the middle frame of the mobile phone is a textured area 2. A plurality of texture sections 21 are uniformly distributed in the texture area 2, and each texture section 21 corresponds to one aluminum alloy grain. Furthermore, the boundaries between the texture patches 21 corresponding to adjacent grains, i.e., grain boundaries, are more visible than before etching and can be easily observed by the naked eye. It is to be understood that although the difference in color depth or the difference in gloss between adjacent crystal grains is not reflected in fig. 4, in reality, the grain boundaries between adjacent crystal grains are more conspicuous mainly due to the increase in the difference in color depth and/or the difference in gloss between adjacent crystal grains.

alternatively, the strong acid solution may include one or more of aqua regia, hydrofluoric acid, and nitric acid.

optionally, the etching temperature is 0-80 deg.C, and the etching time is 3-600 s. According to different requirements of the appearance effect of the workpiece, the proper etching temperature and etching time can be selected. Generally, the higher the etching temperature is, the longer the etching time is, and the higher the concentration of the strong acid solution is, the larger the difference of the degree of corrosion of the strong acid solution to the surface of the workpiece corresponding to the preset block of the second aluminum profile is, and the more obvious the difference of color depth, the difference of glossiness, and the grain boundary between the texture blocks corresponding to the adjacent crystal grains in the texture region of the finally manufactured workpiece are.

S600: and carrying out anodic oxidation treatment on the etched piece to obtain the electronic equipment workpiece.

Anodic oxidation of an aluminum product such as aluminum or an aluminum alloy refers to a process in which the aluminum product is used as an anode, and the aluminum product is placed in an electrolyte solution to be subjected to an electrical treatment, and an aluminum oxide film is formed on the surface thereof by an electrolytic action. The anodic oxidation process can comprise the steps of pretreatment, anodic oxidation, activated dyeing, hole sealing, drying and the like. The pretreatment may include degreasing, alkali washing, neutralization, chemical grinding, ash removal, and the like. The anodization process in the embodiment of the present application may be implemented by using an existing anodization process, which is not described herein again.

The anodic oxidation mainly has the effects of coloring the surface, improving the corrosion resistance, enhancing the wear resistance and hardness, protecting the metal surface and the like. In the embodiment of the application, the surface of the etching part is subjected to anodic oxidation treatment, so that the color depth difference degree or the glossiness difference degree of different crystal grain surfaces can be further improved, and the crystal boundary of the surface of the etching part is further highlighted.

The anodic oxidation treatment in the embodiment of the application can adopt the processes of single-color anodic oxidation, gradual-change anodic oxidation or double-color anodic oxidation and the like, so that the workpiece can obtain different colors on the basis of obtaining 'camouflage' textures, and further the workpiece forms a richer overall appearance effect. When the aluminum oxide film formed by the anodic oxidation treatment is a colorless film, the surface of the final workpiece presents silvery 'camouflage' texture.

By the method, firstly, the aluminum alloy blank is subjected to deformation processing and heat treatment, so that aluminum alloy grains which are visible to naked eyes and are uniformly distributed are formed in at least one preset block of the second aluminum profile. And then, etching the surface of at least one preset block of the second aluminum profile by adopting a strong acid solution. Because the aluminum alloy crystal is visible to naked eyes and the color depth or the glossiness of different crystal grains are obviously different, the grain boundary between the crystal grains can be highlighted and can be observed by naked eyes more easily. And finally, forming an aluminum oxide film on the surface of the workpiece through anodic oxidation treatment, so that the crystal boundary is further highlighted. By the method, the camouflage texture can be formed on the surface of the workpiece, so that the workpiece has a novel appearance effect. In addition, the preparation method is suitable for industrial scale production of the workpiece.

Optionally, after the anodic oxidation treatment, a secondary mechanical treatment may be performed on the anodized surface, where the secondary mechanical treatment may include one or more of polishing, spraying, laser etching, and the like. Through secondary mechanical treatment, the workpiece can obtain more effects of highlight, matte, high matte and the like or other texture effects on the basis of obtaining camouflage textures, so that the workpiece has a richer integral appearance effect.

The following examples further illustrate the technical solutions of the present application, but do not limit the present application to the scope of the following examples. It should be noted that reagents, raw materials and equipment not specifically described in the examples were commercially available directly. The experimental methods not specified for the specific conditions were selected according to the conventional methods and conditions, or according to the commercial instructions.