Nano-injection molded part, preparation method thereof and housing

Abstract

The present application discloses a nano-injection molded part, a preparation method of the nano-injection molded part and a housing. The preparation method of the nano-injection molded part comprises the following steps: processing a through groove on an aluminum alloy-magnesium-lithium alloy double-layer composite material; spraying a ceramic layer on the inner surface of the through groove; performing a first corrosion treatment on the ceramic layer to form first nano micropores on the surface of the ceramic layer; performing a second corrosion treatment on the magnesium-lithium alloy layer of the aluminum alloy-magnesium-lithium alloy double-layer composite material to form second nano micropores on the surface of the magnesium-lithium alloy layer; performing a nano-injection treatment on the surface of the magnesium-lithium alloy layer and the through groove to obtain a nano-injection molded part. The present application solves the technical problem of poor injection molding effect of the existing technology for injection molding an aluminum alloy-magnesium-lithium alloy double-layer composite material.

Description

Technical Field

[0001] The present application relates to the technical field of composite materials, and particularly relates to a nano-injection molded part, a preparation method thereof, and a housing. Background Art

[0002] With the development of technologies such as AR (Augmented Reality) and VR (Virtual Reality), the demand for material lightweighting has become increasingly prominent. As one of the important materials for future applications of AR and VR products, the surface treatment of magnesium-lithium alloy materials mainly focuses on MAO (microarc oxidation) and painting effects, and the surface treatment texture, color and other effects are generally average. The surface of aluminum alloy materials can be treated by anodic oxidation, making the surface color of aluminum alloy materials richer and the texture better. However, many products will composite plastics on the metal shell. For example, many products require no shielding effect on signals. For example, for an aluminum alloy mobile phone, due to the electronic shielding effect of the metal, antenna slots need to be opened and injection molding treatment is carried out on the antenna slots. When composite plastics on the metal shell, micro-hole treatment can be carried out on the connection surface between the metal and the plastic. However, the activity of magnesium-lithium alloy and aluminum alloy materials is different, and there is an electronegativity difference. When using chemical reagents for treatment, it is easy to cause a primary battery reaction between the aluminum alloy and the magnesium-lithium alloy, resulting in serious corrosion of one of the two materials. If the connection surface between the metal and the plastic is not subjected to micro-hole treatment and direct injection molding is carried out, the plastic and the metal at the connection surface between the metal and the plastic are likely to crack, and it is difficult to ensure airtightness. Summary of the Invention

[0003] The main purpose of the present application is to provide a nano-injection molded part, a preparation method thereof, and a housing, aiming to solve the technical problem of poor injection molding effect of injecting an aluminum alloy-magnesium-lithium alloy double-layer composite material in the prior art.

[0004] To achieve the above purpose, the present application provides a preparation method of a nano-injection molded part, and the preparation method of the nano-injection molded part includes the following steps:

[0005] Process a through groove on an aluminum alloy-magnesium-lithium alloy double-layer composite material;

[0006] Spray a ceramic layer on the inner surface of the through groove;

[0007] Perform a first corrosion treatment on the ceramic layer to form first nano-micro holes on the surface of the ceramic layer;

[0008] Perform a second corrosion treatment on the magnesium-lithium alloy layer of the aluminum alloy-magnesium-lithium alloy double-layer composite material to form second nano-micro holes on the surface of the magnesium-lithium alloy layer;

[0009] Perform nano-injection molding treatment on the surface of the magnesium-lithium alloy layer and the through groove to obtain a nano-injection molded part.

[0010] Optionally, the step of performing a first etching treatment on the ceramic layer to form first nano-micro holes on the surface of the ceramic layer includes:

[0011] Perform corrosion-resistant masking treatment on the metal surface of the aluminum alloy-magnesium-lithium alloy bilayer composite material;

[0012] Perform a first etching treatment on the ceramic layer to form first nano-micro holes on the surface of the ceramic layer.

[0013] Optionally, the step of performing a first etching treatment on the ceramic layer to form first nano-micro holes on the surface of the ceramic layer includes:

[0014] Immerse the ceramic layer in a first acidic solution for the first etching treatment to form first nano-micro holes on the surface of the ceramic layer.

[0015] Optionally, the step of performing a second etching treatment on the magnesium-lithium alloy layer of the aluminum alloy-magnesium-lithium alloy bilayer composite material to form second nano-micro holes on the surface of the magnesium-lithium alloy layer includes:

[0016] Immerse the surface of the magnesium-lithium alloy layer of the aluminum alloy-magnesium-lithium alloy bilayer composite material in a salt solution or a second acidic solution for the second etching treatment to form second nano-micro holes on the surface of the magnesium-lithium alloy layer.

[0017] Optionally, the step of spraying a ceramic layer on the inner surface of the through groove includes:

[0018] Perform surface roughening treatment on the inner surface of the through groove;

[0019] Spray a ceramic layer on the roughened inner surface of the groove.

[0020] Optionally, the thickness of the ceramic layer is less than or equal to 0.3 mm.

[0021] Optionally, the material of the ceramic layer includes alumina and / or zirconia.

[0022] This application also provides a nano-injection molded part, which is prepared by using the preparation method of the nano-injection molded part as described above, and the nano-injection molded part includes:

[0023] An aluminum alloy layer;

[0024] A magnesium-lithium alloy layer;

[0025] A through-groove that penetrates the aluminum alloy layer and the magnesium-lithium alloy layer, and the inner surface of the through-groove has a ceramic layer;

[0026] A plastic layer that fills the through-groove and is connected to the magnesium-lithium alloy layer and the ceramic layer.

[0027] This application also provides a housing, which is the housing of an electronic device, and at least part of the housing is made of the nano-injection molded part described above. Among them, the aluminum alloy layer is the appearance surface of the housing, and the plastic layer is the built-in surface of the housing.

[0028] Optionally, the through-groove is an antenna groove.

[0029] This application provides a nano-injection molded part, a preparation method of the nano-injection molded part, and a housing. By processing a through-groove on the aluminum alloy-magnesium-lithium alloy double-layer composite material, the cross-section of the aluminum alloy-magnesium-lithium alloy double-layer composite material is exposed. The cross-section is composed of aluminum alloy and magnesium-lithium alloy, so it is difficult to directly perform corrosion treatment. Furthermore, by spraying a ceramic layer on the inner surface of the through-groove, the protection of the cross-section composed of aluminum alloy and magnesium-lithium alloy is realized. Furthermore, by performing a first corrosion treatment on the ceramic layer, first nano-micro holes are formed on the surface of the ceramic layer, and a second corrosion treatment is performed on the magnesium-lithium alloy layer of the aluminum alloy-magnesium-lithium alloy double-layer composite material, and second nano-micro holes are formed on the surface of the magnesium-lithium alloy layer, realizing the surface treatment of each contact surface to be injection molded, processing a nano-micro hole structure on each contact surface. Furthermore, by performing nano-injection molding treatment on the surface of the magnesium-lithium alloy layer and the through-groove, a nano-injection molded part is obtained, realizing the tight combination of the plastic layer and the aluminum alloy-magnesium-lithium alloy double-layer composite material. And because of the protection of the ceramic layer for the cross-section composed of aluminum alloy and magnesium-lithium alloy, it is possible to improve the bonding tightness between the ceramic layer and the plastic layer by performing corrosion treatment on the ceramic layer, and it is also possible to effectively avoid the situation that any one of the aluminum alloy or magnesium-lithium alloy appears serious corrosion due to the electronegativity difference when performing corrosion treatment on the cross-section, overcoming the technical problem of poor injection molding effect of the existing technology for injecting the aluminum alloy-magnesium-lithium alloy double-layer composite material. Description of the Drawings

[0030] The drawings here are incorporated into the specification and form a part of this specification, showing the embodiments that conform to this application, and are used together with the specification to explain the principles of this application.

[0031] In order to more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, without paying creative labor, other drawings can also be obtained according to these drawings.

[0032] Figure 1 It is a schematic flow chart of an embodiment of the preparation method of the nano-injection molded part of the present application;

[0033] Figure 2 It is a schematic structural diagram of an implementable manner of the through groove in the nano-injection molded part of the present application;

[0034] Figure 3 It is a schematic structural diagram of an embodiment of the nano-injection molded part of the present application.

[0035] Explanation of the reference numerals in the drawings:

[0036] Label Name Label Name 10 Aluminum alloy layer 20 Magnesium-lithium alloy layer 30 Penetrating groove 40 Ceramic layer 50 Plastic layer 31 Groove surface

[0037] The realization of the purpose, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. Specific embodiments

[0038] In order to make the above objects, features and advantages of the present invention more obvious and understandable, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0039] With the development of technology industries such as AR (Augmented Reality) and VR (Virtual Reality), the demand for lightweight materials has become increasingly prominent. As one of the important materials for future applications of AR and VR products, the surface treatment of magnesium-lithium alloy materials mainly focuses on MAO (microarc oxidation) and painting effects, and the surface treatment texture, color and other effects are generally average. The surface of aluminum alloy materials can be treated by anodic oxidation, making the surface color of aluminum alloy materials richer and the texture better. However, the density of aluminum alloy is relatively large, which is not suitable for the lightweight requirements of AR, VR and other products. If a layer of aluminum alloy is compounded on the magnesium-lithium alloy and the aluminum alloy is treated by anodic oxidation, a good appearance texture can be obtained. However, many products will compound and fill plastics on the metal shell to eliminate signal shielding and reduce costs. For example, many products require no signal shielding, such as aluminum alloy mobile phones. Since metals have an electronic shielding effect, antenna slots need to be opened and injection molding treatment is required for the antenna slots. When compounding plastics on the metal shell, microporous treatment can be carried out on the connection surface of the metal and the plastic. Especially when the connection surface of the metal and the plastic includes both aluminum alloy and magnesium-lithium alloy, due to the different activities of magnesium-lithium alloy and aluminum alloy materials and the electronegativity difference, the same chemical reagent cannot be used for treatment, which makes the treatment process extremely complicated and not suitable for industrial processing. If the same chemical reagent is used for treatment, or when different chemical reagents are used, the materials that are not treated are not properly protected, which is likely to cause a galvanic reaction between the aluminum alloy and the magnesium-lithium alloy, resulting in severe corrosion of one of the two materials. If the connection surface of the metal and the plastic is not subjected to microporous treatment and direct injection molding is carried out, the plastic and the metal at the connection surface of the metal and the plastic are likely to crack, and the airtightness is difficult to guarantee.

[0040] An embodiment of the present application provides a method for preparing a nano-injection molded part. In an embodiment of the method for preparing a nano-injection molded part of the present application, with reference to Figure 1 , the method for preparing the nano-injection molded part includes:

[0041] Step S10, processing a through groove on the aluminum alloy-magnesium-lithium alloy double-layer composite material;

[0042] In this embodiment, it should be noted that the aluminum alloy-magnesium lithium alloy double-layer composite material is composed of a magnesium lithium alloy material and an aluminum alloy material. The aluminum alloy-magnesium lithium alloy double-layer composite material can be an aluminum alloy-magnesium lithium alloy composite plate, or a housing substrate made by stamping and forming the aluminum alloy-magnesium lithium alloy composite plate. The aluminum alloy-magnesium lithium alloy double-layer composite material is used to make the housing of an electronic device. The aluminum alloy-magnesium lithium alloy double-layer composite material at least includes a magnesium lithium alloy layer and an aluminum alloy layer. The aluminum alloy layer is used as the appearance surface of the housing, and can be further processed by anodic oxidation to produce a housing appearance surface with rich colors and excellent texture. Due to its excellent light-weighting effect, the magnesium lithium alloy layer is the main part of the electronic device housing and faces the inside of the electronic device. The thickness of the aluminum alloy layer, the thickness of the magnesium lithium alloy layer, and the thickness of the aluminum alloy-magnesium lithium alloy double-layer composite material can be adjusted according to actual needs, and this embodiment does not limit this. For example, the thickness of the magnesium lithium alloy layer is 0.9 mm, and the thickness of the aluminum alloy layer is 0.1 mm; the thickness of the magnesium lithium alloy layer is 0.5 mm, and the thickness of the aluminum alloy layer is 0.04 mm; the thickness of the magnesium lithium alloy layer is 1.2 mm, and the thickness of the aluminum alloy layer is 0.12 mm, etc.

[0043] It is easy to understand that since the density of the aluminum alloy is relatively large, it is not conducive to the light-weighting of the product. Therefore, under the condition that a housing appearance surface with rich colors and excellent texture can be processed, the thickness of the aluminum alloy layer should be reduced as much as possible.

[0044] Specifically, through numerical control machining, cutting, grinding and other processes are performed on the preset machining area of the aluminum alloy-magnesium lithium alloy double-layer composite material to remove part of the material and form a machining cross-section. The space surrounded by the machining cross-section is the through groove. The through groove penetrates the aluminum alloy layer and the magnesium lithium alloy layer of the aluminum alloy-magnesium lithium alloy double-layer composite material. Part of the inner surface of the through groove is aluminum alloy and part is magnesium lithium alloy.

[0045] In an implementable manner, referring to Figure 2 , the aluminum alloy-magnesium lithium alloy double-layer composite material is composed of an aluminum alloy layer 10 and a magnesium lithium alloy layer 20. A through groove 30 is machined on the aluminum alloy-magnesium lithium alloy double-layer composite material. The groove surface 31 of the through groove 30 is the cross-section of the aluminum alloy-magnesium lithium alloy double-layer composite material. Therefore, part of the groove surface 31 is the surface of the aluminum alloy and part is the surface of the magnesium lithium alloy.

[0046] Step S20, spraying a ceramic layer on the inner surface of the through groove;

[0047] In this embodiment, specifically, after cleaning the inner surface of the through-groove to remove surface floating dust, a ceramic layer is sprayed on the inner surface of the through-groove by means of arc, plasma, etc. The specific process parameters of the spraying can be determined according to actual test results, big data, actual conditions, etc., and this embodiment does not limit this. The ceramic layer is a coating made of ceramic material. The material of the ceramic layer may include one or more mixtures of alumina, zirconia, titanium oxide, silicon nitride, boron carbide, etc., and other additives can also be added according to actual needs, and can be specifically determined according to actual needs, and this embodiment does not limit this.

[0048] Optionally, the material of the ceramic layer includes alumina and / or zirconia.

[0049] In this embodiment, specifically, the material of the ceramic layer includes at least one or more mixtures of alumina and zirconia.

[0050] Optionally, the step of spraying a ceramic layer on the inner surface of the through-groove includes:

[0051] Step S21, performing surface roughening treatment on the inner surface of the through-groove;

[0052] Step S22, spraying a ceramic layer on the inner surface of the groove after surface roughening treatment.

[0053] In this embodiment, specifically, the inner surface of the through-groove is subjected to surface roughening treatment to increase the roughness of the inner surface of the groove. Then, the inner surface of the groove after surface roughening treatment is cleaned to remove surface floating dust. After that, ceramic powder is sprayed on the inner surface of the through-groove by means of arc, plasma, etc., and through high-temperature forming, a ceramic layer is formed on the inner surface of the through-groove. The surface roughening treatment methods include physical methods such as mechanical sandblasting and shot peening. By performing surface roughening treatment on the inner surface of the through-groove, the bonding force between the ceramic layer and the inner surface of the through-groove can be effectively improved, so that the ceramic layer is tightly bonded to the through-groove.

[0054] Optionally, the thickness of the ceramic layer is less than or equal to 0.3 mm.

[0055] In this embodiment, specifically, the ceramic layer should be able to completely cover the inner surface of the through-groove, and the thickness of the ceramic layer should be greater than the depth of the nano-micro holes formed by subsequent corrosion treatment, so as to provide anti-corrosion protection for the aluminum alloy and magnesium-lithium alloy on the inner surface of the groove during the subsequent corrosion treatment. The density of the ceramic is relatively large, about 2.4 - 2.9 g / cm 3, the thickness of the ceramic layer only needs to provide anti-corrosion protection for the aluminum alloy and magnesium-lithium alloy on the inner surface of the groove. An overly thick layer is not conducive to the lightweight requirement of the product. Therefore, it is determined that the thickness of the ceramic layer is less than or equal to 0.3 mm.

[0056] Step S30: Perform a first corrosion treatment on the ceramic layer to form first nano-micro holes on the surface of the ceramic layer;

[0057] In this embodiment, specifically, the ceramic layer is immersed in a first corrosion solution for the first corrosion treatment to form first nano-micro holes on the surface of the ceramic layer. Among them, the first corrosion solution can be a mixed solution of one or more of acid solution, alkali solution, salt solution, etc. The specific ratio and process conditions can be determined according to actual test results, corrosion effects, and the tightness of the combination with the plastic layer after corrosion treatment. This embodiment does not limit this.

[0058] Optionally, the step of performing a first corrosion treatment on the ceramic layer to form first nano-micro holes on the surface of the ceramic layer includes:

[0059] Immerse the ceramic layer in a first acidic solution for the first corrosion treatment to form first nano-micro holes on the surface of the ceramic layer.

[0060] In this embodiment, specifically, the ceramic layer is immersed in a first acidic solution for the first corrosion treatment to form first nano-micro holes on the surface of the ceramic layer. At the same time, the first acidic solution should be prevented from contacting the aluminum alloy and magnesium-lithium alloy in the aluminum alloy-magnesium-lithium alloy double-layer composite material to avoid serious corrosion of the aluminum alloy and magnesium-lithium alloy in the aluminum alloy-magnesium-lithium alloy double-layer composite material by the first acidic solution.

[0061] Compared with aluminum alloy and magnesium-lithium alloy, the corrosion resistance of ceramic is stronger. Therefore, a more corrosive corrosion solution is required for the first corrosion treatment of the ceramic layer. Acid solutions with higher concentration and stronger acidity can be used, such as one or more of sulfuric acid, nitric acid, hydrofluoric acid with higher concentration, etc. Fluorides with strong corrosion and penetration effects on ceramics can also be added, such as one or more of sodium fluoride, potassium fluoride, ammonium fluoride, etc.

[0062] In an implementable manner, the first corrosion solution is a mixed solution of ammonium fluoride solution and sulfuric acid solution. In the first corrosion solution, the concentration of ammonium fluoride is 5 - 15 g / L, such as 5 g / L, 10 g / L, 12 g / L, 15 g / L, etc., and the concentration of sulfuric acid is 300 - 400 g / L, such as 300 g / L, 322 g / L, 350 g / L, 400 g / L, etc.

[0063] In an implementable manner, the temperature of the first corrosion treatment is 70-90 °C, such as 70 °C, 80 °C, 82 °C, 90 °C, etc.

[0064] In an implementable manner, the time of the first corrosion treatment is 10-20 min, such as 10 min, 12 min, 15 min, 20 min, etc.

[0065] Optionally, the step of performing the first corrosion treatment on the ceramic layer to form first nano micropores on the surface of the ceramic layer includes:

[0066] Step S31, performing a corrosion-resistant masking treatment on the metal surface of the aluminum alloy-magnesium-lithium alloy double-layer composite material;

[0067] Step S32, performing the first corrosion treatment on the ceramic layer to form first nano micropores on the surface of the ceramic layer

[0068] In this embodiment, specifically, the exposed aluminum alloy surface and magnesium-lithium alloy surface on the aluminum alloy-magnesium-lithium alloy double-layer composite material are subjected to a corrosion-resistant masking treatment to ensure that neither the aluminum alloy layer nor the magnesium-lithium alloy layer of the aluminum alloy-magnesium-lithium alloy double-layer composite material will be corroded during the subsequent first corrosion treatment. Furthermore, the aluminum alloy-magnesium-lithium alloy double-layer composite material after the corrosion-resistant masking treatment is immersed in a first corrosion solution for the first corrosion treatment to form first nano micropores on the surface of the ceramic layer. Among them, the corrosion-resistant masking treatment includes tape masking, ink masking, paint masking, etc. Through the corrosion-resistant masking treatment, the first corrosion solution will not corrode the aluminum alloy or magnesium-lithium alloy in the aluminum alloy-magnesium-lithium alloy double-layer composite material, and thus the protection of the aluminum alloy layer and magnesium-lithium alloy layer in the aluminum alloy-magnesium-lithium alloy double-layer composite material can be achieved. The masking substances such as tape, ink, paint, etc. added to the surface of the aluminum alloy-magnesium-lithium alloy double-layer composite material during the corrosion-resistant masking treatment can be removed after the first corrosion treatment.

[0069] Step S40, performing a second corrosion treatment on the magnesium-lithium alloy layer of the aluminum alloy-magnesium-lithium alloy double-layer composite material to form second nano micropores on the surface of the magnesium-lithium alloy layer;

[0070] In this embodiment, specifically, the magnesium-lithium alloy layer of the aluminum alloy-magnesium-lithium alloy double-layer composite material is immersed in a second corrosion solution for the second corrosion treatment to form second nano micropores on the surface of the magnesium-lithium alloy layer. Among them, the second corrosion solution can be a mixed solution of one or more of acid solution, alkali solution, salt solution, etc. The specific ratio and process conditions can be determined according to the actual test results, corrosion effect, and tightness of the combination with the plastic layer after the corrosion treatment. This embodiment does not limit this.

[0071] Optionally, the step of performing a second corrosion treatment on the magnesium-lithium alloy layer of the aluminum alloy-magnesium-lithium alloy double-layer composite material to form second nano-micropores on the surface of the magnesium-lithium alloy layer includes:

[0072] Immerse the surface of the magnesium-lithium alloy layer of the aluminum alloy-magnesium-lithium alloy double-layer composite material in a salt solution or a second acidic solution to perform a second corrosion treatment, and form second nano-micropores on the surface of the magnesium-lithium alloy layer.

[0073] In this embodiment, specifically, immerse the surface of the magnesium-lithium alloy layer of the aluminum alloy-magnesium-lithium alloy double-layer composite material in a salt solution or a second acidic solution with less corrosion to perform a second corrosion treatment, and form second nano-micropores on the surface of the magnesium-lithium alloy layer. At the same time, contact between the second acidic solution and the aluminum alloy in the aluminum alloy-magnesium-lithium alloy double-layer composite material should be avoided to prevent a primary battery reaction from occurring between the aluminum alloy and the magnesium-lithium alloy in the second acidic solution, and to avoid over-corrosion and damage to the aluminum alloy layer or the magnesium-lithium alloy layer.

[0074] It is easy to understand that since the second corrosion treatment of the magnesium-lithium alloy layer does not require treatment of the entire magnesium-lithium alloy layer, only the surface of the magnesium-lithium alloy layer that needs to be injection-molded needs to be treated. Therefore, only the magnesium-lithium alloy layer with a preset height can be immersed in the salt solution or the second acidic solution. Therefore, by controlling the height of the magnesium-lithium alloy layer immersed in the salt solution or the second acidic solution, contact between the aluminum alloy and the salt solution or the second acidic solution can be avoided, and corrosion-resistant shielding treatment can also be performed on the surface of the aluminum alloy layer of the aluminum alloy-magnesium-lithium alloy double-layer composite material. This embodiment does not limit this, and ceramics will not form a primary battery reaction with the magnesium-lithium alloy, so there is no need to perform anti-corrosion protection on the ceramic layer.

[0075] Compared with ceramics, the corrosion resistance of the magnesium-lithium alloy is weaker. Therefore, the corrosiveness of the second corrosion solution for performing the second corrosion treatment on the magnesium-lithium alloy layer is weaker than that of the first corrosion solution used in the first corrosion treatment, and an acid solution or a salt solution with a smaller concentration and weaker acidity can be used.

[0076] In an implementable manner, the second corrosion solution is a hydrochloric acid solution, and the concentration of the hydrochloric acid solution is 0.05 - 0.1 mol / L, such as 0.05 mol / L, 0.08 mol / L, 0.1 mol / L, etc.

[0077] In an implementable manner, the temperature of the second corrosion treatment is 15 - 20 °C, such as 15 °C, 18 °C, 20 °C, etc.

[0078] In an implementable manner, the time of the first corrosion treatment is 1 - 3 min, such as 1 min, 1.5 min, 3 min, etc.

[0079] Step S50, perform nano-injection molding on the surface of the magnesium-lithium alloy layer and the through groove to obtain a nano-injection molded part.

[0080] In this embodiment, specifically, perform nano-injection molding on the surface of the magnesium-lithium alloy layer and the through groove so that the plastic fills the surface of the magnesium-lithium alloy layer and the through groove to form a plastic layer, and obtain a nano-injection molded part composed of an aluminum alloy layer, a magnesium-lithium alloy layer, a ceramic layer, and a plastic layer. The nano-injection molding includes T treatment and injection molding processing, and the specific process parameters can be determined according to actual test results, big data, actual situations, etc., and this embodiment does not limit this.

[0081] In this embodiment, by processing a through groove on the aluminum alloy-magnesium-lithium alloy double-layer composite material, the cross-section of the aluminum alloy-magnesium-lithium alloy double-layer composite material is exposed. The cross-section is composed of an aluminum alloy and a magnesium-lithium alloy, so it is difficult to directly perform corrosion treatment. Furthermore, by spraying a ceramic layer on the inner surface of the through groove, the protection of the cross-section composed of an aluminum alloy and a magnesium-lithium alloy is realized. Furthermore, by performing a first corrosion treatment on the ceramic layer, first nano-micro holes are formed on the surface of the ceramic layer, and a second corrosion treatment is performed on the magnesium-lithium alloy layer of the aluminum alloy-magnesium-lithium alloy double-layer composite material, and second nano-micro holes are formed on the surface of the magnesium-lithium alloy layer, realizing the surface treatment of each contact surface to be injection molded, processing a nano-micro hole structure on each contact surface. Furthermore, by performing nano-injection molding on the surface of the magnesium-lithium alloy layer and the through groove, a nano-injection molded part is obtained, realizing the tight combination of the plastic layer and the aluminum alloy-magnesium-lithium alloy double-layer composite material. Perform a pull-out force test on the nano-injection molded part, and the measured pull-out force is greater than or equal to 200 kfg, which is much greater than the pull-out force that the injection molded part obtained by directly performing injection molding on the metal surface without surface micro-hole treatment can withstand. That is, the preparation method of the nano-injection molded part provided in this embodiment can effectively improve the tight combination of the plastic and the metal in the nano-injection molded part. And due to the protection of the cross-section composed of an aluminum alloy and a magnesium-lithium alloy by the ceramic layer, it is possible to improve the tight combination density of the ceramic layer and the plastic layer by performing corrosion treatment on the ceramic layer, and at the same time, when performing corrosion treatment on the cross-section, it is possible to effectively avoid the situation that any one of the aluminum alloy or the magnesium-lithium alloy appears serious corrosion due to the difference in electronegativity, overcoming the technical problem of poor injection molding effect of the existing technology for injection molding the aluminum alloy-magnesium-lithium alloy double-layer composite material.

[0082] Furthermore, the present invention also provides a nano-injection molded part, which is prepared by using the preparation method of the nano-injection molded part as described above. In an embodiment of the nano-injection molded part of the present application, refer toFigure 3 , the nano-injection molded part includes:

[0083] an aluminum alloy layer 10;

[0084] a magnesium-lithium alloy layer 20;

[0085] a through groove that penetrates the aluminum alloy layer 10 and the magnesium-lithium alloy layer 20, and the inner surface of the through groove has a ceramic layer 40;

[0086] a plastic layer 50 that fills the through groove and is connected to the magnesium-lithium alloy layer 20 and the ceramic layer 40.

[0087] The nano-injection molded part provided by this application solves the technical problem of poor injection molding effect of the prior art for injection molding of an aluminum alloy-magnesium-lithium alloy double-layer composite material. Compared with the prior art, the beneficial effects of the nano-injection molded part provided by the embodiments of the present invention are the same as those of the preparation method of the nano-injection molded part in the above embodiments, and will not be elaborated here.

[0088] Furthermore, the present invention also provides a housing, the housing is a housing of an electronic device, at least part of the housing is made of the above-mentioned nano-injection molded part, wherein, the aluminum alloy layer is the appearance surface of the housing, the plastic layer is the inner surface of the housing, and the through groove is a hollow space on the housing, and the specific use can be determined according to the actual situation, and this embodiment does not limit this.

[0089] Optionally, the through groove is an antenna groove.

[0090] The nano-injection molded part provided by this application solves the technical problem of poor injection molding effect of the prior art for injection molding of an aluminum alloy-magnesium-lithium alloy double-layer composite material. Compared with the prior art, the beneficial effects of the nano-injection molded part provided by the embodiments of the present invention are the same as those of the preparation method of the nano-injection molded part in the above embodiments, and will not be elaborated here

[0091] The above are only the preferred embodiments of this application, and do not limit the patent scope of this application accordingly. All equivalent structural or equivalent process transformations made by using the content of the specification and drawings of this application, or directly or indirectly applied in other related technical fields, are equally included in the patent scope of this application.

Claims

1. A preparation method of a nano-injection molded part, characterized in that, The preparation method of the nano-injection molded part comprises the following steps; Machining a through groove on the aluminum alloy-magnesium-lithium alloy double-layer composite material; Spraying a ceramic layer on the inner surface of the through groove; Performing corrosion-resistant shielding treatment on the metal surface of the aluminum alloy-magnesium-lithium alloy double-layer composite material; Performing a first corrosion treatment on the ceramic layer to form first nano-micro holes on the surface of the ceramic layer, and removing the shielding material added to the metal surface during the corrosion-resistant shielding treatment; Performing a second corrosion treatment on the magnesium-lithium alloy layer of the aluminum alloy-magnesium-lithium alloy double-layer composite material to form second nano-micro holes on the surface of the magnesium-lithium alloy layer; Performing nano-injection molding treatment on the surface of the magnesium-lithium alloy layer and the through groove to obtain a nano-injection molded part.

2. The preparation method of the nano-injection molded part according to claim 1, characterized in that, The step of performing a first corrosion treatment on the ceramic layer to form first nano-micro holes on the surface of the ceramic layer comprises: Immersing the ceramic layer in a first acidic solution for the first corrosion treatment to form first nano-micro holes on the surface of the ceramic layer.

3. The preparation method of the nano-injection molded part according to claim 1, wherein, The step of performing a second corrosion treatment on the magnesium-lithium alloy layer of the aluminum alloy-magnesium-lithium alloy double-layer composite material to form second nano-micro holes on the surface of the magnesium-lithium alloy layer comprises: Immersing the surface of the magnesium-lithium alloy layer of the aluminum alloy-magnesium-lithium alloy double-layer composite material in a salt solution or a second acidic solution for the second corrosion treatment to form second nano-micro holes on the surface of the magnesium-lithium alloy layer.

4. The preparation method of the nano-injection molded part according to claim 1, characterized in that, The step of spraying a ceramic layer on the inner surface of the through groove comprises: Performing surface roughening treatment on the inner surface of the through groove; Spraying a ceramic layer on the inner surface after the surface roughening treatment.

5. The preparation method of the nano-injection molded part according to claim 1, characterized in that, The thickness of the ceramic layer is less than or equal to 0.3 mm.

6. The preparation method of the nano-injection molded part according to claim 1, characterized in that, The material of the ceramic layer includes alumina and / or zirconia.

7. A nano-injection molded part, characterized in that, The nano-injection molded part is prepared by using the preparation method of the nano-injection molded part according to any one of claims 1 to 6, and the nano-injection molded part comprises: An aluminum alloy layer; A magnesium-lithium alloy layer; A through groove that penetrates the aluminum alloy layer and the magnesium-lithium alloy layer, and the inner surface of the through groove has a ceramic layer; A plastic layer that fills the through groove and is connected to the magnesium-lithium alloy layer and the ceramic layer.

8. A housing, characterized in that, The housing is a housing of an electronic device, and at least part of the housing is made of the nano-injection molded part according to claim 7, wherein the aluminum alloy layer is the appearance surface of the housing, and the plastic layer is the built-in surface of the housing.

9. The housing according to claim 8, characterized in that, The through groove is an antenna groove.

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