Manufacturing method of local anode of magnesium alloy shell

Abstract

The invention discloses a manufacturing method for a local anode of a magnesium alloy shell. The manufacturing method comprises the following steps that S1, a magnesium alloy part body is obtained through a die casting technology; s2, the magnesium alloy layer and the aluminum alloy layer are pre-riveted, a composite board with the aluminum alloy layer and the magnesium alloy layer stacked up and down is obtained through a rolling process, and a strip-shaped composite material with a certain width is taken from the composite board; s3, bending the composite material to obtain a U-shaped composite material with a magnesium alloy layer on the inner side and an aluminum alloy layer on the outer side; s4, fixedly connecting the U-shaped composite material with the magnesium alloy plate body; s5, CNC machining is conducted on the component obtained in the step S4, and redundant structures are removed; s6, the magnesium alloy shell is subjected to anti-corrosion surface treatment and then is subjected to drying treatment; s7, the surface of the magnesium alloy shell is subjected to drying treatment after coloring treatment; s8, mirror finishing is conducted on the aluminum alloy layer on the periphery of the magnesium alloy shell; and S9, highlight anodic treatment is conducted on the mirror face part machined in the step S8. According to the manufacturing method, the high-brightness appearance effect of the magnesium alloy shell can be achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic products, and particularly relates to a manufacturing method for local anodization of a magnesium alloy housing. Background Art

[0002] Due to the limitations of the die-casting process and the material itself, traditional magnesium alloy die-castings are prone to product defects such as sand holes and air holes inside the product. The surface treatment methods are also single processes such as painting, which cannot fully reflect the metallic texture at all. And magnesium alloy profiles require multiple CNC machining processes, resulting in high costs. However, the advantages of magnesium alloy in terms of density and strength are irreplaceable by other metal materials. Therefore, it is necessary to improve the metallic appearance texture of magnesium alloy. Summary of the Invention

[0003] The object of the present invention is to provide a manufacturing method for local anodization of a magnesium alloy housing, which can achieve a high-gloss effect on the magnesium alloy housing.

[0004] Based on the above problems, the technical solution provided by the present invention is as follows:

[0005] A manufacturing method for local anodization of a magnesium alloy housing, comprising the following steps:

[0006] S1. Obtain a magnesium alloy part body by using a die-casting process;

[0007] S2. Perform pre-riveting on the magnesium alloy layer and the aluminum alloy layer, and obtain a composite plate with the aluminum alloy layer and the magnesium alloy layer stacked up and down through a rolling process. Take a strip-shaped composite material with a certain width on the composite plate;

[0008] S3. Bend the strip-shaped composite material obtained in step S2 to obtain a U-shaped composite material with the magnesium alloy layer on the inner side and the aluminum alloy layer on the outer side;

[0009] S4. Place the U-shaped composite material obtained in step S3 on the outer periphery of the magnesium alloy plate body obtained in step S1, and fixedly connect the U-shaped composite material with the magnesium alloy plate body;

[0010] S5. Perform CNC machining on the component obtained in step S4 to remove redundant structures and obtain a magnesium alloy housing;

[0011] S6. Perform anti-corrosion surface treatment on the magnesium alloy housing obtained in step S5 and then perform drying treatment;

[0012] S7. Perform surface coloring treatment on the magnesium alloy housing obtained in step S6 and then perform drying treatment;

[0013] S8. Perform mirror machining on the aluminum alloy layer on the outer periphery of the magnesium alloy housing obtained in step S7;

[0014] S9. Perform high-brightness anodic treatment on the mirror surface part processed in step S8.

[0015] In some of these embodiments, the thickness of the magnesium alloy layer in step S2 is 2 - 5 mm, and the thickness of the aluminum alloy layer is 1 - 3 mm.

[0016] In some of these embodiments, the width of the strip-shaped composite material in step S2 is 5 - 10 mm.

[0017] In some of these embodiments, in step S4, friction stir welding or laser welding is used to fixedly connect the U-shaped composite material to the magnesium alloy part body.

[0018] In some of these embodiments, the anti-corrosion surface treatment in step S6 is a chemical conversion process or a micro-arc oxidation (MAO) process.

[0019] In some of these embodiments, the coloring treatment in step S7 is spray painting treatment or electrophoretic treatment.

[0020] In some of these embodiments, an MCD tool is used to machine a mirror structure in step S8.

[0021] In some of these embodiments, a PCD tool is used to machine a mirror structure in step S8, and then polishing treatment is performed.

[0022] Compared with the prior art, the advantages of the present invention are:

[0023] By combining a magnesium-aluminum alloy composite material with magnesium alloy on the inner side and aluminum alloy on the outer side on the outer periphery of the magnesium alloy part body to obtain a magnesium alloy housing, a high-brightness appearance effect of the magnesium alloy housing can be achieved while reducing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. The drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0025] Figure 1 It is a schematic structural diagram of a magnesium alloy housing obtained by a manufacturing method for local anodization of a magnesium alloy housing of the present invention;

[0026] Figure 2 It is a schematic cross-sectional structure diagram of the composite material in the embodiment of the present invention;

[0027] Among them:

[0028] 1. Magnesium alloy part body;

[0029] 2. Composite material; 2-1. Magnesium alloy layer; 2-2. Aluminum alloy layer. Detailed implementation manners

[0030] The above solution will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are for illustrating the present invention and not for limiting the scope of the present invention. The implementation conditions adopted in the embodiments can be further adjusted according to the conditions of specific manufacturers, and the implementation conditions not specified are usually the conditions in conventional experiments.

[0031] The present invention provides a method for manufacturing a locally anodic magnesium alloy housing, including the following steps:

[0032] S1. Obtain the magnesium alloy part body 1 by die-casting process;

[0033] S2. Use an automatic riveting machine to pre-rivet the magnesium alloy layer 2-1 and the aluminum alloy layer 2-2, and obtain a composite plate with the magnesium alloy layer 2-1 and the aluminum alloy layer 2-2 stacked up and down through a rolling process. Take a strip-shaped composite material 2 with a certain width on the composite plate;

[0034] S3. Bend the strip-shaped composite material 2 obtained in step S2 to obtain a U-shaped composite material 2 with the magnesium alloy layer 2-1 on the inner side and the aluminum alloy layer 2-2 on the outer side, as Figure 2 shown;

[0035] S4. Place the U-shaped composite material 2 obtained in step S3 on the outer periphery of the magnesium alloy plate body 1 obtained in step S1, and fixedly connect the U-shaped composite material 2 with the magnesium alloy plate body 1;

[0036] S5. Perform CNC machining on the component obtained in step S4 to remove redundant structures to obtain a magnesium alloy housing;

[0037] S6. Perform anti-corrosion surface treatment on the magnesium alloy housing obtained in step S5 and then perform drying treatment;

[0038] S7. Perform surface coloring treatment on the magnesium alloy housing obtained in step S6 and then perform drying treatment;

[0039] S8. Perform mirror machining on the aluminum alloy layer on the outer periphery of the magnesium alloy housing obtained in step S7;

[0040] S9. Perform high-gloss anodic treatment on the mirror surface part processed in step S8 to obtain the magnesium alloy housing as Figure 1 shown.

[0041] The magnesium alloy part body obtained by die-casting process in step S1 is the large surface part of the magnesium alloy housing. The required magnesium alloy part body is die-cast from magnesium alloy AZ91D by semi-solid die-casting process.

[0042] In step S2, aluminum alloy (the grade can be A16063 or A15052, which can be switched according to the actual product requirements) and AZ31B magnesium alloy materials are pre-riveted and aligned at the material head, and then the materials are preheated to 350 - 450 °C. After sufficient preheating, they are subjected to composite rolling on a rolling mill. After obtaining the composite sheet by composite rolling, the thickness of the magnesium alloy layer is 2 - 5 mm, and the thickness of the aluminum alloy layer is 1 - 3 mm. A strip-shaped composite material with a certain width is taken from the composite sheet, and the width of the strip-shaped composite material is 5 - 10 mm.

[0043] In step S4, friction stir welding or laser welding is used to fixedly connect the U-shaped composite material with the magnesium alloy part body. Since the inner side of the composite material is the magnesium alloy layer, it is convenient to perform welding and fixation with the magnesium alloy part body, while the outer side of the composite material is the aluminum alloy layer, which can ensure the high-brightness appearance effect of the product.

[0044] In step S5, CNC machining is mainly performed on the welding position of the magnesium alloy shell and the composite material.

[0045] In step S6, the anti-corrosion surface treatment is a chemical conversion process or a MAO (micro-arc oxidation) process. The chemical conversion process and the MAO process are common processes in the prior art, and will not be elaborated in this invention.

[0046] The surface coloring treatment in step S7 is spray painting treatment or electrophoretic treatment. On the one hand, it can color the magnesium alloy shell to optimize the appearance, and on the other hand, it can perform anodic shielding on the magnesium alloy part body to facilitate subsequent high-bright anodic treatment.

[0047] In step S8, a mirror structure is machined using an MCD (single-crystal diamond) tool, or a mirror structure is machined using a PCD (polycrystalline diamond) tool and then polished.

[0048] The high-bright anodic treatment in step S9 is a process in the prior art. The magnesium alloy shell obtained in step S8 is placed in an electrolyte, and anodic oxidation is carried out for 30 - 60 minutes under the conditions of a voltage of 12 - 20 V, a current density of 1 - 2 A / dm 2 , and a temperature of 15 - 25 °C, and then soaked in pure water at 90 - 100 °C for 20 - 30 minutes for high-temperature hydration sealing.

[0049] In summary, the magnesium alloy shell prepared by this method can achieve a high-brightness effect and reduce production costs.

[0050] The above examples are only for illustrating the technical concept and characteristics of the present invention, and the purpose is to enable those familiar with this technology to understand the content of the present invention and implement it accordingly, and it cannot be used to limit the protection scope of the present invention. All equivalent transformations or modifications made according to the spirit and essence of the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for manufacturing a local anode of a magnesium alloy shell, characterized in that: The following steps are involved: S1. A magnesium alloy body is obtained by die casting process; S2, pre-riveting the magnesium alloy layer and the aluminum alloy layer, obtaining a composite plate in which the aluminum alloy layer and the magnesium alloy layer are stacked up and down through a rolling process, and taking a strip composite material of a certain width on the composite plate; S3, bending the strip-shaped composite material obtained in step S2 to obtain a U-shaped composite material with a magnesium alloy layer on the inner side and an aluminum alloy layer on the outer side; S4, placing the U-shaped composite material obtained in step S3 on the periphery of the magnesium alloy plate body obtained in step S1, and fixing the U-shaped composite material to the magnesium alloy plate body; S5, performing CNC processing on the component obtained in step S4 to remove redundant structures to obtain a magnesium alloy shell; S6, performing anti-corrosion surface treatment and then drying treatment on the magnesium alloy shell obtained in step S5; S7, performing a coloring treatment and then a drying treatment on the surface of the magnesium alloy shell obtained in step S6; S8, mirror-finishing the aluminum alloy layer on the outer periphery of the magnesium alloy shell obtained in step S7; S9, performing high-gloss anodizing treatment on the mirror surface processed in step S8.

2. The method for manufacturing a local anode of a magnesium alloy shell according to claim 1, characterized in that: In step S2, the thickness of the magnesium alloy layer is 2-5 mm, and the thickness of the aluminum alloy layer is 1-3 mm.

3. The method for manufacturing a local anode of a magnesium alloy shell according to claim 2, characterized in that: In step S2, the width of the strip composite material is 5 to 10 mm.

4. The method for manufacturing a local anode of a magnesium alloy shell according to claim 1, characterized in that: In step S4, friction stir welding or laser welding is used to fix the U-shaped composite material and the magnesium alloy component body.

5. The method for manufacturing a local anode of a magnesium alloy shell according to claim 1, characterized in that: The anti-corrosion surface treatment in step S6 is a chemical formation process or a MAO process.

6. The method for manufacturing a partial anode of a magnesium alloy shell according to claim 1, characterized in that: The coloring process in step S7 is a painting process or an electrophoresis process.

7. The method for manufacturing a partial anode of a magnesium alloy shell according to claim 1, characterized in that: In step S8, a mirror structure is machined using an MCD tool.

8. The method for manufacturing a partial anode of a magnesium alloy shell according to claim 1, characterized in that: In step S8, a PCD tool is used to machine a mirror structure, and then a polishing process is performed.

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