Metal material, metal plastic connecting material, preparation method and application

Abstract

The invention relates to the technical field of metal surface treatment, in particular to a metal material, a metal plastic connecting material, a preparation method and application. The surface treatment method of the metal material comprises the following steps: performing micro-arc oxidation treatment on the surface of a metal substrate to form a micro-arc oxidation layer; etching the micro-arc oxidation layer by adopting a chemical etching solution to form an etching hole; the chemical etching liquid comprises potassium permanganate, organic acid and ammonium bifluoride, so that the depth of the etching hole is smaller than the thickness of the micro-arc oxidation layer.

Description

Technical Field

[0001] This application relates to the technical field of metal surface treatment, and particularly to a metal material, a metal-plastic connection material, a preparation method and an application thereof. Background Art

[0002] Due to the different properties of metals and plastics, with different thermal expansion coefficients and interfacial energies, the bonding force between them is often weak. After long-term thermal shock, it is easy to crack, resulting in poor appearance and other performance problems of some equipment that uses the combination of metal and plastic. Currently, a physical mortise and tenon structure design is usually adopted to achieve the combination of metal and plastic. However, due to the complex structure, this design poses certain difficulties to the injection molding process. Moreover, due to the existence of a large number of glue-grabbing structures, the potential risks of seams and appearance quality are relatively high.

[0003] To improve the bonding force between metal and plastic and achieve the forming combination of metal and plastic on the premise of ensuring simplicity of the structure, a chemical treatment method is required to microporize the surface of the metal material structure, so as to achieve the penetration of plastic into the micropores and ensure the precise combination of plastic and metal.

[0004] However, the microporization treatment will damage the anti-oxidation coating on the metal surface, leading to pitting corrosion of the metal material and increasing the risk of corrosion during product use. Summary of the Invention

[0005] In view of this, the technical problem to be solved by this application is to provide a metal material, a metal-plastic connection material, a preparation method and an application thereof.

[0006] This application provides a surface treatment method for a metal material, including:

[0007] Performing micro-arc oxidation treatment on the surface of a metal substrate to form a micro-arc oxidation layer;

[0008] Etching the micro-arc oxidation layer with a chemical etching solution to form etching holes;

[0009] The chemical etching solution includes potassium permanganate, organic acid and ammonium bifluoride, and the depth of the etching holes is less than the thickness of the micro-arc oxidation layer.

[0010] This application provides a metal material, including a substrate layer and a micro-arc oxidation layer provided on the surface of the substrate layer;

[0011] The substrate layer is a dense layer;

[0012] The micro-arc oxidation layer has etching holes, and the depth of the etching holes is less than the thickness of the micro-arc oxidation layer.

[0013] This application provides a method for connecting metal and plastic, including:

[0014] Micro-arc oxidation treatment is carried out on the surface of a metal substrate to form a micro-arc oxidation layer;

[0015] The micro-arc oxidation layer is etched with a chemical etching solution to form etching holes;

[0016] The chemical etching solution includes potassium permanganate, organic acid and ammonium bifluoride, and the depth of the etching holes is less than the thickness of the micro-arc oxidation layer;

[0017] Part or all of the plastic material is injected into the etching holes, and after curing, the connection between the metal substrate and the plastic material is realized.

[0018] The present application provides a metal-plastic connection material, including a metal substrate and a plastic material;

[0019] The metal substrate includes a substrate layer and a micro-arc oxidation layer provided on the surface of the substrate layer;

[0020] The substrate layer is a dense layer;

[0021] The micro-arc oxidation layer has etching holes, and the depth of the etching holes is less than the thickness of the micro-arc oxidation layer;

[0022] The plastic material is at least partially filled in the etching holes to be connected with the metal material.

[0023] The present application provides an electronic device, and the electronic device includes:

[0024] A housing;

[0025] The housing includes a metal housing body and a plastic part;

[0026] At least part of the surface of the metal housing body is provided with a micro-arc oxidation layer;

[0027] The micro-arc oxidation layer has etching holes, and the depth of the etching holes is less than the thickness of the micro-arc oxidation layer;

[0028] The plastic part is at least partially filled in the etching holes to be connected with the metal housing body. Description of the Drawings

[0029] Figure 1 It is a flowchart of the metal-plastic connection method provided by the present application;

[0030] Figure 2 It is a schematic diagram of the etched metal material provided by the present application;

[0031] Figure 3 It is a schematic diagram of the metal-plastic connector provided by the present application. Detailed Description of the Invention

[0032] It should be noted that, without conflict, the embodiments in the present application and the technical features in the embodiments can be combined with each other. The detailed description in the specific implementation manners should be understood as an explanatory illustration of the purpose of the present application and should not be regarded as an improper limitation to the present application.

[0033] To make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the following will further describe the specific technical solutions of the present application in detail with reference to the accompanying drawings in the embodiments of the present application. The following embodiments are used to illustrate the present application but are not used to limit the scope of the present application.

[0034] In the embodiments of the present application, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the embodiments of the present application, unless otherwise stated, the meaning of "a plurality" is two or more.

[0035] In addition, in the embodiments of the present application, orientation terms such as "upper", "lower", "left" and "right" are defined relative to the orientation of the components shown in the drawings. It should be understood that these directional terms are relative concepts, and they are used for relative description and clarification, and they may change correspondingly according to the change of the orientation of the components placed in the drawings.

[0036] In the embodiments of the present application, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or integrated; it can be directly connected or indirectly connected through an intermediate medium.

[0037] In the embodiments of the present application, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, the element defined by the statement "including one..." does not exclude the existence of additional identical elements in the process, method, article or device including such element.

[0038] In the embodiments of the present application, words such as "exemplary" or "for example" are used to represent examples, illustrations or explanations. Any embodiment or design solution described as "exemplary" or "for example" in the embodiments of the present application should not be construed as being more preferred or more advantageous than other embodiments or design solutions. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0039] The present application provides a surface treatment method for a metal material, including:

[0040] Performing micro-arc oxidation treatment on the surface of a metal substrate to form a micro-arc oxidation layer;

[0041] Etching the micro-arc oxidation layer with a chemical etching solution to form etching holes;

[0042] The chemical etching solution includes potassium permanganate, organic acid and ammonium bifluoride, and the depth of the etching holes is less than the thickness of the micro-arc oxidation layer.

[0043] The present application first performs micro-arc oxidation treatment on the surface of a metal substrate to form a micro-arc oxidation layer.

[0044] The micro-arc oxidation treatment can be a micro-arc oxidation treatment applicable to the surface of a metal well-known to those skilled in the art.

[0045] In some embodiments of the present application, the micro-arc oxidation solution used in the micro-arc oxidation treatment may include: sodium hydroxide, potassium fluoride and sodium silicate.

[0046] In some embodiments of the present application, the content of the sodium hydroxide may be 10-20 g / L.

[0047] In some embodiments of the present application, the content of the sodium hydroxide may be 10, 15 or 20 g / L.

[0048] In some embodiments of the present application, the content of the potassium fluoride may be 4-6 g / L.

[0049] In some embodiments of the present application, the content of the potassium fluoride may be 4, 5 or 6 g / L.

[0050] In some embodiments of the present application, the content of the sodium silicate may be 7-9 g / L.

[0051] In some embodiments of the present application, the content of the sodium silicate may be 7, 8 or 9 g / L.

[0052] In some embodiments of the present application, the solvent of the micro-arc oxidation solution may be water.

[0053] In some embodiments of the present application, the micro-arc oxidation solution may include:

[0054]

[0055] In some embodiments of the present application, the temperature of the micro-arc oxidation treatment can be 20 to 30 °C.

[0056] In some embodiments of the present application, the temperature of the micro-arc oxidation treatment can be 20, 25 or 30 °C.

[0057] In some embodiments of the present application, the time of the micro-arc oxidation treatment can be 10 to 30 min.

[0058] In some embodiments of the present application, the time of the micro-arc oxidation treatment can be 10, 15 or 20 min.

[0059] In some embodiments of the present application, the current density of the micro-arc oxidation treatment can be 1 to 5 A / dm 2 。

[0060] In some embodiments of the present application, the current density of the micro-arc oxidation treatment can be 1, 3 or 5 A / dm 2 。

[0061] In some embodiments of the present application, a dense micro-arc oxidation layer is formed on the surface of the metal substrate under the above conditions.

[0062] In some embodiments of the present application, the thickness of the micro-arc oxidation layer can be 5 to 10 μm.

[0063] Then, a chemical etching solution is used to etch the micro-arc oxidation layer on the surface of the metal substrate to form etching holes.

[0064] In some embodiments of the present application, the metal substrate can be a magnesium alloy material.

[0065] Due to poor corrosion resistance, the magnesium alloy substrate needs to be subjected to surface treatments such as anti-oxidation and wear resistance. If chemical etching is used to form holes in the magnesium alloy material, pitting corrosion of the magnesium alloy cannot be avoided, which will pose a certain risk to the potential future corrosion of the magnesium alloy.

[0066] To achieve the goal of microporosity of the magnesium alloy substrate, it is desired that the magnesium alloy substrate itself does not pose a potential pitting risk. Therefore, it is necessary to develop a suitable microporosity treatment agent for magnesium alloy to achieve a strong bond between the magnesium alloy and the plastic.

[0067] In this application, a chemical etching solution containing potassium permanganate, organic acid, and ammonium bifluoride is used to etch the micro-arc oxidation layer. Among them, the organic acid serves as an acidic solvent and can dissolve the micro-arc oxidation layer; ammonium bifluoride contains a large amount of fluoride ions. In an organic acid environment, fluoride ions have good etching performance and have a strong dissolving ability for metal ions and oxides such as silicon, copper, and nickel in the micro-arc oxidation layer. Potassium permanganate can etch the micro-arc oxidation layer by reacting with the organic acid during the etching process. The dissolving ability of the pure organic acid for the dense micro-arc oxidation layer is limited and uniform dissolution is likely to occur. Under the combined action of potassium permanganate, selective pitting dissolution occurs on the film layer, which can effectively increase the density and size of the etching holes; at the same time, when the etching holes develop down to the substrate, due to its passivation ability and combined with the fluoride ions in ammonium bifluoride to form a dense passivation film, it can effectively protect the substrate metal from corrosion.

[0068] In some embodiments of this application, the metal substrate is a magnesium alloy substrate. When the above etching solution contacts the magnesium alloy substrate, magnesium fluoride insoluble matter can be formed and a composite film of fluoride and oxide can be generated together with potassium permanganate, preventing the etching solution from diffusing and corroding the magnesium alloy substrate.

[0069] Under the action of the above etching solution, the depth of the formed etching holes is less than the thickness of the micro-arc oxidation layer.

[0070] In this application, the "depth" refers to the length of the etching hole in the vertical direction, that is, the depth of the pit formed during the etching process.

[0071] When the depth of the etching holes is less than the thickness of the micro-arc oxidation layer, the etching only occurs in the micro-arc oxidation layer and will not have any impact on the surface of the metal substrate. The impacts include causing etching holes on the metal surface and / or damaging any protective coating on the surface of the metal substrate and / or exposing the magnesium alloy material, etc.

[0072] In some embodiments of this application, the depth of the etching holes can be 2 - 3 μm.

[0073] In some embodiments of this application, the content of potassium permanganate can be 5 - 8 g / L.

[0074] In some embodiments of this application, the content of potassium permanganate can be 5, 5.5, 6, 6.5, 7, 7.5, or 8 g / L.

[0075] In some embodiments of this application, the content of the organic acid can be 60 - 80 g / L.

[0076] In some embodiments of this application, the content of the organic acid can be 60, 70, or 80 g / L.

[0077] In some embodiments of the present application, the organic acid may include: tartaric acid and / or citric acid.

[0078] In some embodiments of the present application, the content of ammonium bifluoride may be 10-20 g / L.

[0079] In some embodiments of the present application, the content of ammonium bifluoride may be 10, 15 or 20 g / L.

[0080] In some embodiments of the present application, the etching solution may further include: polyethylene glycol.

[0081] Polyethylene glycol has good hydrophilicity and thickening properties, can adjust the surface tension of the etching solution on the micro-arc oxidation layer, and adjust the overall viscosity of the etching solution, so that the etching solution and the micro-arc oxidation layer can have good contact. At the same time, polyethylene glycol has certain slow-release agent characteristics, adsorbs on the material surface, and slows down the etching degree.

[0082] In some embodiments of the present application, the polyethylene glycol may be polyethylene glycol 1000.

[0083] In some embodiments of the present application, the content of polyethylene glycol may be 10-15 g / L.

[0084] In some embodiments of the present application, the content of polyethylene glycol may be 10, 12 or 15 g / L.

[0085] In some embodiments of the present application, the etching solution may further include: alkyl polyglucoside (APG).

[0086] Alkyl polyglucoside has good water solubility and hydrophilicity, can adjust the surface tension of the etching solution, and synergistically with polyethylene glycol, can increase the infiltration and spreading of the etching solution on the surface of the micro-arc oxidation layer, and accelerate the contact reaction between the two; at the same time, due to its good surfactant characteristics, it is easy to produce weak adsorption on the surface of the micro-arc oxidation layer, can compete with the organic acid for adsorption, effectively control the reaction speed, and has a good effect on controlling the reaction speed of the etching solution and effectively controlling the reaction degree.

[0087] In some embodiments of the present application, the content of alkyl polyglucoside may be 3-5 g / L.

[0088] In some embodiments of the present application, the content of alkyl polyglucoside may be 3, 3.5, 4, 4.5 or 5 g / L.

[0089] In some embodiments of the present application, the etching solution may include:

[0090] Potassium permanganate 5-8 g / L;

[0091] Organic acid: 60 - 80 g / L;

[0092] Ammonium bifluoride: 10 - 20 g / L;

[0093] The organic acid includes: tartaric acid and / or citric acid.

[0094] In some embodiments of the present application, the etching solution further includes:

[0095] Polyethylene glycol: 10 - 15 g / L;

[0096] And / or, the etching solution further includes:

[0097] Dodecyl glucoside: 3 - 5 g / L.

[0098] The solvent of the etching solution can be water.

[0099] In some embodiments of the present application, the etching solution may include:

[0100]

[0101] Water.

[0102] In some embodiments of the present application, the temperature of the etching can be 20 - 30 °C.

[0103] In some embodiments of the present application, the temperature of the etching can be 20, 25 or 30 °C.

[0104] In some embodiments of the present application, the time of the etching can be 60 - 180 s.

[0105] In some embodiments of the present application, the time of the etching can be 60, 90 or 180 s.

[0106] The present application does not limit the etching method, and dipping, spraying and other methods can be selected according to the requirements of the product.

[0107] In some embodiments of the present application, according to the need of the subsequent bonding strength between the plastic and the metal, the pore adjustment can be realized by adjusting the pore structure of the micro-arc oxidation film layer and the etching solution.

[0108] In some embodiments of the present application, before the above micro-arc oxidation operation, it may further include: pre-treating the metal substrate.

[0109] The present application does not limit the process and steps of the pre-treatment, and any pre-treatment of the metal substrate well-known to those skilled in the art before the micro-arc oxidation operation can be used.

[0110] In some embodiments of the present application, the pre-treatment may include: one or more of degreasing, dewaxing, etc.

[0111] The present application does not limit the specific operation of the above degreasing, which can be the degreasing treatment of the metal surface well-known in the art.

[0112] The present application does not limit the specific operation of the above wax removal, and a wax remover can be used to perform wax removal treatment on the surface after polishing.

[0113] The present application does not limit the sequence of degreasing and wax removal, and degreasing can be carried out first and then wax removal, or wax removal can be carried out first and then degreasing.

[0114] In some embodiments of the present application, based on the usage requirements of the product, the metal substrate can also be subjected to one or more of the pretreatment including but not limited to CNC high gloss, polishing, primer setting, etc.

[0115] The present application does not limit the specific operation of the above CNC high gloss, and a CNC numerical control machine tool can be used to perform high-speed CNC fine machining on the surface of the die-casting part to achieve the high gloss effect.

[0116] The present application does not limit the specific operation of the above polishing, and a polishing wheel can be used to polish the surface of the die-casting part to form a high gloss metal surface. A polishing paste can be used during the polishing process, and the polishing paste includes at least one of but not limited to vaseline, paraffin wax, stearic acid, etc.

[0117] The above primer includes one or more of but not limited to a transparent conversion film, a polymer film, a primer for spraying or electrophoretic coating, etc.

[0118] The setting of the above primer can be freely adjusted according to the performance requirements of the product, and the present application does not limit it.

[0119] The present application provides a metal material, including a substrate layer and a micro-arc oxidation layer provided on the surface of the substrate layer;

[0120] The substrate layer is a dense layer;

[0121] The micro-arc oxidation layer has etching holes, and the depth of the etching holes is less than the thickness of the micro-arc oxidation layer.

[0122] The fact that the substrate layer is a dense layer means that there are no etching holes of any form and any size on the surface and inside of the substrate layer.

[0123] The above metal material provided by the present application can be used as a connector with plastic.

[0124] The present application provides a method for connecting metal and plastic, including the following steps:

[0125] Perform micro-arc oxidation treatment on the surface of the metal substrate to form a micro-arc oxidation layer;

[0126] Etch the micro-arc oxidation layer with a chemical etching solution to form etching holes;

[0127] The chemical etching solution includes potassium permanganate, organic acid and ammonium bifluoride, so that the depth of the etching holes is less than the thickness of the micro-arc oxidation layer;

[0128] Inject part or all of the plastic material into the etching holes, and after curing, realize the connection between the metal substrate and the plastic material.

[0129] The above micro-arc oxidation and etching have been described in detail above and will not be elaborated here.

[0130] In some embodiments of the present application, between the etching and injecting part or all of the plastic material into the etching holes, there further includes: hole inner film covering treatment;

[0131] The hole inner film covering treatment uses a treatment solution to treat the surface of the etching holes, and forms a nano-micro adhesion layer on the surface of the etching holes to improve the bonding force between the metal and the plastic;

[0132] The treatment solution includes: acrylic acid, hydroxyethyl acrylate and silane coupling agent.

[0133] The present application uses the above treatment solution to treat the surface of the etching holes, improving the bonding force between the metal and the plastic material.

[0134] Among them, acrylic acid has good hydrophilicity and a large number of hydrophilic groups of carboxyl, which can be effectively adsorbed on the pore surface to form a surface with more active reaction groups, creating favorable conditions for subsequent plastic injection molding. On the one hand, it can form chemical bonding with the metal oxide film or the metal surface, and on the other hand, it can bond with the active groups in the injected plastic material, playing a good bonding bridge role between the substrate and the plastic.

[0135] In some embodiments of the present application, the content of the acrylic acid can be 5-8 g / L.

[0136] In some embodiments of the present application, the content of the acrylic acid can be 5, 5.5, 6, 6.5, 7, 7.5 or 8 g / L.

[0137] Due to the existence of the hydroxyethyl group, hydroxyethyl acrylate can effectively improve the toughness of the adhesion layer, so that the film will not become hard and brittle, cracked or fragmented during the baking and curing process.

[0138] In some embodiments of the present application, the content of the hydroxyethyl acrylate can be 2-4 g / L.

[0139] In some embodiments of the present application, the content of hydroxyethyl acrylate may be 2, 2.5, 3, 3.5, or 4 g / L.

[0140] After hydrolysis in an acidic condition, the silane coupling agent forms a large number of silanol groups, which can further improve the bonding ability of acrylic carboxyl groups to the oxide film and the metal substrate. At the same time, the epoxy group of the KH560 silane coupling agent also has high reactivity and can undergo ring-opening addition reactions with substances containing active groups such as hydroxyl and amino groups in the subsequent injection molding material, thereby strengthening the chemical bonding with the injection molding material.

[0141] In some embodiments of the present application, the content of the silane coupling agent may be 2 - 5 g / L.

[0142] In some embodiments of the present application, the content of the silane coupling agent may be 2, 2.5, 3, 3.5, 4, 4.5, or 5 g / L.

[0143] In some embodiments of the present application, the silane coupling agent is KH-560.

[0144] In some embodiments of the present application, the treatment liquid includes:

[0145] Acrylic acid 5 - 8 g / L;

[0146] Hydroxyethyl acrylate 2 - 4 g / L;

[0147] Silane coupling agent 2 - 5 g / L.

[0148] In some embodiments of the present application, the treatment liquid may further include: ethanol.

[0149] Ethanol has good hydrophilicity and solubility, can increase the solubility and pore penetration ability of acrylic acid and hydroxyethyl acrylate, and increase the miscibility of the treatment liquid with water.

[0150] In some embodiments of the present application, the content of ethanol may be 80 - 100 g / L.

[0151] In some embodiments of the present application, the content of ethanol may be 80, 90, or 100 g / L.

[0152] In some embodiments of the present application, the solvent of the treatment liquid may be water.

[0153] In some embodiments of the present application, the temperature of the in-hole film coating treatment may be 20 - 30 °C.

[0154] In some embodiments of the present application, the temperature of the in-hole film coating treatment may be 20, 25, or 30 °C.

[0155] In some embodiments of the present application, the time for the in-hole film coating treatment can be 60 to 180 s.

[0156] In some embodiments of the present application, the time for the in-hole film coating treatment can be 60, 90, 120 or 180 s.

[0157] The present application does not limit the method for the in-hole film coating treatment, and methods such as dip coating and spraying can be selected according to the requirements of the product.

[0158] In some embodiments of the present application, after the in-hole film coating treatment is completed, the metal material can be dried.

[0159] In some embodiments of the present application, the metal material is dried.

[0160] In some embodiments of the present application, the temperature for drying can be 80 to 100 °C.

[0161] In some embodiments of the present application, the time for drying can be 20 to 30 min.

[0162] The present application does not specifically limit the plastic material, and it can be a generally applicable thermoplastic resin.

[0163] In some embodiments of the present application, the plastic material can be selected from materials such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyphenylene sulfide (PPS), etc.

[0164] In some embodiments of the present application, additives can also be added to the plastic material.

[0165] In some embodiments of the present application, glass fiber (GF) can be added to the plastic material to improve the strength of the plastic material.

[0166] The present application does not limit the addition amount of the glass fiber, and those skilled in the art can selectively add it according to the mechanical property requirements of the material.

[0167] The present application does not limit the injection method of the plastic material, and it can be an applicable method well-known to those skilled in the art.

[0168] In some embodiments of the present application, part or all of the plastic material can be injected into the etching holes by an injection molding process.

[0169] In some embodiments of the present application, the injection molding process can adopt five-stage heating.

[0170] Five-stage heating means that the barrel of the injection molding machine is provided with five heating sections.

[0171] In some embodiments of the present application, the five-stage heating may be as follows:

[0172] T1: 325 °C;

[0173] T2: 325 °C;

[0174] T3: 320 °C;

[0175] T4: 300 °C;

[0176] T5: 270 °C.

[0177] The above T1, T2, T3, T4, and T5 are the temperatures of the five heating sections respectively.

[0178] Among them, the first section (T1): The temperature is relatively low. Its main function is to preheat the plastic particles just entering the barrel, making the plastic particles soften initially, and at the same time preventing the plastic from melting prematurely near the hopper, which may cause poor feeding.

[0179] The second section (T2) and the third section (T3): The temperature gradually increases, making the plastic particles soften further and start to melt. By appropriately increasing the temperature, the plastic particles can fully absorb heat, accelerating the melting process and laying a foundation for the subsequent plasticization uniformity.

[0180] The fourth section (T4): The temperature is usually set relatively high, which is the area where the plastic is completely melted and reaches a good plasticized state. In this section, the plastic needs to reach a sufficient temperature and fluidity so that it can flow smoothly towards the nozzle under the push of the screw.

[0181] The fifth section (T5, nozzle section): The temperature is generally slightly lower than that of the fourth section, mainly to prevent the plastic from overheating and decomposing at the nozzle, and at the same time ensure that the plastic has appropriate fluidity during injection, so that it can be smoothly injected into the mold cavity.

[0182] Inject part or all of the plastic material into the etching holes, and after curing, realize the connection between the metal substrate and the plastic material

[0183] In some embodiments of the present application, all of the plastic material is injected into the etching holes, and after curing, it is completely connected to the metal substrate.

[0184] In some embodiments of the present application, part of the plastic material is injected into the etching holes. After curing, the injected plastic material is connected to the metal substrate, and the remaining plastic material becomes other components of the workpiece, such as buttons, etc.

[0185] The present application provides a metal-plastic connection material, including a metal substrate and a plastic material;

[0186] The metal substrate includes a substrate layer and a micro-arc oxidation layer provided on the surface of the substrate layer;

[0187] The substrate layer is a dense layer;

[0188] The micro-arc oxidation layer has etching holes, and the depth of the etching holes is less than the thickness of the micro-arc oxidation layer;

[0189] At least part of the plastic material is filled in the etching holes to be connected with the metal material.

[0190] This application provides an electronic device, and the electronic device includes:

[0191] A housing;

[0192] The housing includes a metal housing body and a plastic part;

[0193] At least part of the surface of the metal housing body is provided with a micro-arc oxidation layer;

[0194] The micro-arc oxidation layer has etching holes, and the depth of the etching holes is less than the thickness of the micro-arc oxidation layer;

[0195] At least part of the plastic part is filled in the etching holes to be connected with the metal housing body.

[0196] This application does not limit the position where the micro-arc oxidation layer is provided, and those skilled in the art can select according to product requirements, including but not limited to the inner side, outer side, side, etc. of the housing.

[0197] In some embodiments of this application, the position of the plastic part corresponds to the position of the signal transmitting and / or receiving components in the electronic device, so as to avoid the shielding of electromagnetic signals by metal parts.

[0198] To further illustrate this application, the following will be described in detail with reference to embodiments. However, it should be understood that these descriptions are only for further illustrating the features and advantages of this application, rather than limiting the claims of the invention.

[0199] For all raw materials of this application, there is no special limitation on their sources, and they can be purchased on the market or prepared by conventional methods well-known to those skilled in the art.

[0200] Example 1

[0201] The process flow is as follows:

[0202] 1. Degrease the magnesium alloy material. The degreasing solution uses TY-M19 degreasing solution (Sanqing Chemical Industry), with a concentration of 5%, a temperature of 50 °C, and a time of 120 s.

[0203] 2. Micro-arc oxidation treatment:

[0204] Treatment solution:

[0205]

[0206] Process parameters:

[0207] Temperature: 25°C;

[0208] Time: 20 min;

[0209] Current density: 3 A / dm 2 . 3. Chemical etching:

[0210] Etching solution:

[0211]

[0212] Treatment parameters:

[0213] Temperature: 25°C;

[0214] Time: 90 s;

[0215] Dip coating.

[0216] 4. Inner hole film coating treatment: Treatment solution:

[0217]

[0218] Treatment parameters:

[0219] Temperature: 25°C

[0220] Time: 90 s;

[0221] Dip coating.

[0222] 5. Drying:

[0223] Temperature: 80°C;

[0224] Time: 30 min.

[0225] 6. Plastic injection molding:

[0226] Injection molding machine tonnage: 360 T;

[0227] Plastic particle composition: PPS + 50% GF;

[0228] Nozzle five-stage temperature setting:

[0229] T1: 325°C;

[0230] T2: 325°C;

[0231] T3: 320°C;

[0232] T4: 300°C;

[0233] T5: 270°C;

[0234] The mold temperature of the injection mold is set to: 135°C.

[0235] Example 2

[0236] The process flow is as follows:

[0237] 1. Degrease the magnesium alloy material. The degreasing solution uses TY-M19 degreasing solution (Sanqing Chemical Industry), with a concentration of 5%, a temperature of 65°C, and a time of 120 s.

[0238] 2. Micro-arc oxidation treatment:

[0239] Treatment solution:

[0240]

[0241] Process parameters:

[0242] Temperature: 25°C;

[0243] Time: 20 min;

[0244] Current density: 3 A / dm 2 .

[0245] 3. Chemical etching:

[0246] Etching solution:

[0247]

[0248] Treatment parameters:

[0249] Temperature: 25°C;

[0250] Time: 120 s;

[0251] Dip coating.

[0252] 4. Inner hole film coating treatment:

[0253] Treatment solution:

[0254]

[0255] Treatment parameters:

[0256] Temperature: 25°C

[0257] Time: 120 s;

[0258] Dip coating.

[0259] 5. Drying:

[0260] Temperature: 100°C;

[0261] Time: 20 min.

[0262] 6. Plastic injection molding:

[0263] Tonnage of injection molding machine: 360T;

[0264] Composition of plastic particles: PPS + 50% GF; Five-stage temperature setting of nozzle:

[0265] T1: 325°C;

[0266] T2: 325°C;

[0267] T3: 320°C;

[0268] T4: 300°C;

[0269] T5: 270°C;

[0270] Mold temperature of injection mold is set at: 135°C.

[0271] Example 3

[0272] The process flow is as follows:

[0273] 1. Degrease the magnesium alloy material. The degreasing solution uses TY-M19 degreasing solution (Sanqing Chemical Industry), with a concentration of 5%, a temperature of 50°C, and a time of 120s.

[0274] 2. Micro-arc oxidation treatment:

[0275] Treatment solution:

[0276]

[0277] Process parameters:

[0278] Temperature: 25°C;

[0279] Time: 20 min;

[0280] Current density: 3 A / dm 2 .

[0281] 3. Chemical etching:

[0282] Etching solution:

[0283]

[0284] Treatment parameters:

[0285] Temperature: 25°C;

[0286] Time: 90s;

[0287] Dip coating.

[0288] 4. Plastic injection molding:

[0289] Injection molding machine tonnage: 360T;

[0290] Plastic particle composition: PPS + 50% GF;

[0291] Five - stage temperature setting of the nozzle:

[0292] T1: 325°C;

[0293] T2: 325°C;

[0294] T3: 320°C;

[0295] T4: 300°C;

[0296] T5: 270°C;

[0297] The mold temperature of the injection mold is set to: 135°C.

[0298] Example 4

[0299] The process flow is as follows:

[0300] 1. Degrease the magnesium alloy material. The degreasing solution uses TY - M19 degreasing solution (Sanqing Chemical Industry), with a concentration of 5%, a temperature of 50°C, and a time of 120s.

[0301] 2. Micro - arc oxidation treatment:

[0302] Treatment solution:

[0303]

[0304] Process parameters:

[0305] Temperature: 25°C;

[0306] Time: 20min;

[0307] Current density: 3A / dm 2 .

[0308] 3. Chemical etching:

[0309] Etching solution:

[0310]

[0311] Dodecyl glucoside (APG) 3.5g / L; Deionized water to make up 1L; Treatment parameters:

[0312] Temperature: 25°C;

[0313] Time: 90s;

[0314] Dip coating.

[0315] 4. Inner - hole film - covering treatment:

[0316] Treatment liquid:

[0317] Ethanol 90 g / L;

[0318] Silane coupling agent (KH-560) 20 g / L;

[0319] Deionized water to make up 1 L; Treatment parameters:

[0320] Temperature: 25 °C

[0321] Time: 90 s;

[0322] Dip coating.

[0323] 5. Drying:

[0324] Temperature: 80 °C;

[0325] Time: 30 min.

[0326] 6. Plastic injection molding:

[0327] Injection molding machine tonnage: 360 T;

[0328] Plastic particle composition: PPS + 50% GF;

[0329] Five-stage temperature setting of the nozzle:

[0330] T1: 325 °C;

[0331] T2: 325 °C;

[0332] T3: 320 °C;

[0333] T4: 300 °C;

[0334] T5: 270 °C;

[0335] The mold temperature of the injection mold is set to: 135 °C.

[0336] Comparative Example 1

[0337] The process flow is as follows:

[0338] 1. Degrease the magnesium alloy material. The degreasing liquid uses TY-M19 degreasing liquid (Sanqing Chemical Industry), with a concentration of 5%, a temperature of 50 °C, and a time of 120 s.

[0339] 2. Micro-arc oxidation treatment:

[0340] Treatment liquid:

[0341]

[0342] Process parameters:

[0343] Temperature: 25 °C;

[0344] Time: 20 min;

[0345] Current density: 3 A / dm 2 .

[0346] 3. Chemical etching:

[0347] Etching solution:

[0348] NaOH aqueous solution (pH = 13);

[0349] Processing parameters:

[0350] Temperature: 25 °C;

[0351] Time: 90 s;

[0352] Dip coating.

[0353] After the magnesium alloy is treated by micro-arc oxidation, an oxide ceramic layer mainly composed of magnesium oxide and silicon oxide is formed on the surface of the magnesium alloy. Using an etching solution mainly composed of sodium hydroxide will not cause etching holes in this film layer because the oxide film is relatively stable under alkaline conditions, and the effect of conventional alkaline etching solutions is limited, and the influence on the film holes is small.

[0354] 4. Plastic injection molding:

[0355] Tonnage of injection molding machine: 360 T;

[0356] Composition of plastic particles: PPS + 50% GF;

[0357] Five-stage temperature setting of the nozzle:

[0358] T1: 325 °C;

[0359] T2: 325 °C;

[0360] T3: 320 °C;

[0361] T4: 300 °C;

[0362] T5: 270 °C;

[0363] The mold temperature of the injection mold is set to: 135 °C.

[0364] Performance testing:

[0365] The pull-out failure test was carried out on the magnesium alloy plastic connectors prepared in Examples 1-3 and Comparative Examples 1-2, and the results are shown in Table 1.

[0366] Table 1

[0367] Serial number Drawing breaking force / Kgf Example 1 38.5 Example 2 36 Example 3 23 Example 4 28 Comparative example 1 16

[0368] The description of the above embodiments is only used to help understand the method and its core idea of the present application. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the protection scope of the claims of the present application.

Claims

1. A surface treatment method for a metal material, comprising: Performing micro-arc oxidation treatment on the surface of the metal substrate to form a micro-arc oxidation layer; Etching the micro-arc oxidation layer with a chemical etching solution to form etching holes; The chemical etching solution comprises potassium permanganate, organic acid and ammonium bifluoride, so that the depth of the etching hole is smaller than the thickness of the micro-arc oxidation layer.

2. The method according to claim 1, characterized in that The metal substrate is a magnesium alloy material.

3. The method according to claim 1, characterized in that The thickness of the micro-arc oxidation layer is 5 to 10 μm; The depth of the etching hole is 2-3 μm.

4. The method according to claim 1, characterized in that The etching solution comprises: Potassium permanganate 5-8 g / L; Organic acid 60-80 g / L; Ammonium bifluoride 10-20 g / L; The organic acid includes: tartaric acid and / or citric acid.

5. A metal material comprising a substrate layer and a micro-arc oxidation layer disposed on the surface of the substrate layer; The base layer is a dense layer; The micro-arc oxidation layer has an etching hole, and the depth of the etching hole is less than the thickness of the micro-arc oxidation layer.

6. A method for connecting metal and plastic, comprising: Performing micro-arc oxidation treatment on the surface of the metal substrate to form a micro-arc oxidation layer; Etching the micro-arc oxidation layer with a chemical etching solution to form etching holes; The chemical etching solution includes potassium permanganate, organic acid and ammonium bifluoride, so that the depth of the etching hole is smaller than the thickness of the micro-arc oxidation layer; The plastic material is partially or completely injected into the etching hole, and the connection between the metal substrate and the plastic material is achieved after solidification.

7. The method according to claim 6, characterized in that Between the etching and the injection of the plastic material into the etching hole, the following steps are also included: coating treatment in the hole; The in-hole coating treatment uses a treatment liquid to treat the surface of the etching hole, forming a nano-micron adhesion layer on the surface of the etching hole to improve the bonding force between metal and plastic; The treatment liquid comprises: acrylic acid, hydroxyethyl acrylate and a silane coupling agent.

8. The method according to claim 7, characterized in that The treatment liquid comprises: Acrylic acid 5-8g / L; Hydroxyethyl acrylate 2-4 g / L; Silane coupling agent 2~5g / L.

9. A metal-plastic connecting material, comprising a metal substrate and a plastic material; The metal substrate comprises a base layer and a micro-arc oxidation layer arranged on the surface of the base layer; The base layer is a dense layer; The micro-arc oxidation layer has an etching hole, and the depth of the etching hole is less than the thickness of the micro-arc oxidation layer; The plastic material at least partially fills the etching hole and is connected to the metal material.

10. An electronic device, comprising: case; The housing comprises a metal shell body and a plastic part; At least part of the surface of the metal shell body is provided with a micro-arc oxidation layer; The micro-arc oxidation layer has an etching hole, and the depth of the etching hole is less than the thickness of the micro-arc oxidation layer; The plastic part is at least partially filled in the etching hole and connected to the metal shell body.

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