阅读说明：本技术 树脂-金属复合体和制备方法，以及壳体 (Resin-metal composite body and production method, and case ) 是由 张云侠 宋文广 邓善全 陈梁 于 2019-08-22 设计创作，主要内容包括：本发明公开了树脂-金属复合体和制备方法,以及壳体。该方法包括：提供金属基体,并对所述金属基体在无机碱性溶液中进行浸泡处理；对经过所述浸泡处理的所述金属基体在碱性电解液中进行阳极氧化处理,以便在所述金属基体的至少部分表面形成多孔氧化膜；以及在所述金属基体上具有所述多孔氧化膜的位置处注塑树脂,以形成所述树脂-金属复合体。该方法可利用环境友好的试剂对金属基体进行处理,且最终获得的树脂-金属复合体的树脂以及金属之间的结合强度较强。(The invention discloses a resin-metal composite and a preparation method thereof, and a shell. The method comprises the following steps: providing a metal matrix, and soaking the metal matrix in an inorganic alkaline solution; anodizing the metal matrix subjected to the soaking treatment in an alkaline electrolyte so as to form a porous oxide film on at least part of the surface of the metal matrix; and injection molding a resin at a position having the porous oxide film on the metal substrate to form the resin-metal composite. The method can utilize environment-friendly reagents to treat the metal matrix, and the finally obtained resin-metal composite has stronger bonding strength between the resin and the metal.)

1. A method of making a resin-metal composite comprising:

providing a metal matrix, and soaking the metal matrix in an inorganic alkaline solution;

anodizing the metal matrix subjected to the soaking treatment in an alkaline electrolyte so as to form a porous oxide film on at least part of the surface of the metal matrix; and

injecting a resin at a position having the porous oxide film on the metal substrate to form the resin-metal composite.

2. The method as claimed in claim 1, wherein the porous oxide film comprises macropores with a pore size of 100-30000nm and micropores with a pore size of 20-300nm, and the thickness of the porous oxide film is 100-500 nm.

3. The method according to claim 1 or 2, wherein the inorganic alkaline solution comprises at least one of a hydroxide of an alkali metal, and a salt of a strong alkali and a weak acid.

4. The method according to claim 3, wherein the concentration of the solute in the inorganic alkaline solution is 250g to 400 g/L.

5. The method according to claim 4, wherein the temperature of the inorganic alkaline solution is 50 to 70 ℃ and the soaking time is 20 to 120 minutes.

6. The method as claimed in claim 1 or 2, wherein the alkaline electrolyte comprises inorganic alkali, the concentration of the electrolyte in the alkaline electrolyte is 400-500g/L, the temperature of the alkaline electrolyte is 10-40 ℃ and the time is 5-30 minutes when the anodic oxidation treatment is performed,

optionally, controlling the voltage of the anode in the anodic oxidation process to be 5-15V,

optionally, controlling the current density of the anode in the anodic oxidation process to be 0.2-0.8A/dm²。

7. The method of claim 1 or 2, further comprising at least one of:

before the metal matrix is soaked in an inorganic alkaline solution, polishing, deoiling and first cleaning are carried out on the metal matrix in advance;

after the soaking treatment is carried out on the metal matrix and before the anodic oxidation treatment is carried out on the metal matrix, carrying out second cleaning treatment on the soaked metal matrix;

and after the metal matrix is subjected to the anodic oxidation treatment and before resin injection, performing third cleaning treatment and drying treatment on the metal matrix.

8. A resin-metal composite, comprising:

the metal substrate is provided with a porous oxide film on at least part of the surface, and the porous oxide film comprises macropores with the pore diameter of 100-30000nm and micropores with the pore diameter of 20-300 nm; and

an injection molding part formed of a resin, the injection molding part being located at a position on the metal base body where the porous oxide film is present.

9. The resin-metal composite of claim 8, wherein the resin-metal composite is prepared using the method of any one of claims 1-7.

10. A housing, characterized in that it comprises the resin-metal composite body according to claim 8 or 9.

Technical Field

The invention relates to the field of materials, in particular to a resin-metal composite body and a preparation method thereof, and a shell.

Background

Titanium and titanium alloys are light in weight, high in specific strength, strong in mechanical properties, and good in corrosion resistance and fatigue resistance. The heat stability and corrosion resistance of the titanium alloy are far better than those of the aluminum alloy, the glossiness of the titanium alloy after polishing is higher than that of the aluminum alloy, the glossiness of the titanium alloy is close to that of stainless steel, the density of the titanium alloy is lower than that of the stainless steel, and the titanium alloy is light in weight. Therefore, titanium and titanium alloy have a wide application prospect in the field of materials for housings and inner members of electronic products (such as mobile phones, notebook computers, tablet computers and the like), and are increasingly favored by mobile phone terminal manufacturers. To solve the problem of shielding the signal by a housing made of metal (such as the aforementioned titanium and titanium alloy), it is usually necessary to open a slot in the metal housing and fill the slot with a non-conductive material to form an antenna slot. For example, metal and plastic are currently used in combination with integrated sheet materials to form the housing. For example, titanium and titanium alloys may be surface treated and then injection molded in a mold to form a plastic antenna seam.

However, the current resin-metal composites and methods of preparation, as well as housings, remain to be improved.

Disclosure of Invention

The present invention is based on the discovery and recognition by the inventors of the following facts and problems:

as described above, in order to prevent the all-metal case from shielding the signal, the case is generally formed of a resin-metal composite. To enhance the bond between the injection molded plastic and the metal substrate, the metal surface is typically first treated prior to injection molding. The surface treatment process for titanium and titanium alloy mainly comprises acidic corrosion and alkaline electrochemistry. The acidity mainly uses hydrofluoric acid, hydrochloric acid and the like as main solutions to corrode the titanium alloy, so that holes are formed on the surface of the titanium alloy, the plastic can enter the holes during molding, and the bonding force between the titanium alloy and the plastic is enhanced. Although the method can improve the bonding strength of titanium and titanium alloy, the used solution often needs to be added with organic additives or halogen ions, so that the method has the disadvantages of great environmental pollution, high sewage treatment cost and unsuitability for large-scale production. In addition, hydrofluoric acid is too corrosive, has great harm to human bodies and is not beneficial to industrial production. Although the prior alkaline electrochemical treatment can alleviate the problem of environmental pollution, the composite formed by the prior alkaline method has low bonding strength. Therefore, if an environmentally friendly and reliable preparation method with reliable bonding strength can be provided, the technical problems can be greatly alleviated or even solved.

In view of the above, in one aspect of the present invention, a method of preparing a resin-metal composite is provided. The method comprises the following steps: providing a metal matrix, and soaking the metal matrix in an inorganic alkaline solution; anodizing the metal matrix subjected to the soaking treatment in an alkaline electrolyte so as to form a porous oxide film on at least part of the surface of the metal matrix; and injection molding a resin at a position having the porous oxide film on the metal substrate to form the resin-metal composite. The method can utilize environment-friendly reagents to treat the metal matrix, and the finally obtained resin-metal composite has stronger bonding strength between the resin and the metal.

In another aspect of the invention, the invention features a resin-metal composite. The resin-metal complex comprises a metal matrix, wherein at least part of the surface of the metal matrix is provided with a porous oxide film, and the porous oxide film comprises macropores with the pore diameter of 100-30000nm and micropores with the pore diameter of 20-300 nm; and an injection-molded part formed of a resin, the injection-molded part being located on the metal base body where the porous oxide film is present. Generally, the plate has at least one of the advantages of low production cost, small environmental pollution, reliable bonding strength and the like.

In yet another aspect of the present invention, a housing is presented. The housing includes the resin-metal composite described above. The shell thus has all the features and advantages of the complex described above, which are not described in detail here. Generally, the shell has at least one of the advantages of low production cost, environment-friendly preparation process, long service life and the like.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 shows a schematic flow diagram of a method of making a resin-metal composite body according to one embodiment of the invention;

FIG. 2 shows a schematic flow diagram of a method of making a resin-metal composite body according to another embodiment of the invention;

FIG. 3 shows a scanning electron microscope photograph of an anodized metal substrate according to an embodiment of the invention;

fig. 4 shows a schematic structural view of a resin-metal composite body according to an embodiment of the present invention.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.

In one aspect of the invention, a method of making a resin-metal composite is presented. Specifically, the invention adopts a hot alkali soaking mode to form densely distributed pits with larger size on a metal substrate (for example, the surface of titanium and titanium alloy can be used), and the width of the pits can be in the range of 100-30000 nm. And then, carrying out electrochemical treatment in an electrolyte mainly containing an alkaline solution, such as low-pressure anodic oxidation treatment, so as to form a porous oxide film with a complex microstructure, i.e. with large pores and small pores nested on the surface of the titanium and the titanium alloy with pits (large pores) on the surface. The pore diameter of the pores formed in the anodic oxidation process can be 20-300nm, and the thickness of the film layer of the porous oxide film can be between 100 nm and 500 nm. Therefore, a layer of macropores with the thickness of 100-500nm and the thickness of 100-30000nm can be formed on the surface of the obtained metal substrate, and meanwhile, a complex structure with micropores with the diameters of 20-300nm is nested in the macropores. After the metal matrix with the structure is subjected to injection molding in the mold, the metal matrix and the plastic can achieve high bonding strength, and the bonding strength can reach more than 32 MPa. Further, a complicated structure can be formed on the metal base by injection molding, and a resin-metal composite can be formed with the metal base by injection molding of various materials (e.g., PPS, PBT, PA, etc.). In general, the method has at least one of the advantages of simple process conditions, strong operability, no environmental pollution in the treatment process and the like.

It is specifically noted herein that "large pores" are defined in the present application as being formed during the hot alkali soaking process, and "small pores" are defined during the anodization process. Therefore, when the parameters of the hot alkali soaking treatment and the anodic oxidation treatment are different, the specific pore size range of the large pores is different from that of the small pores. For example, in some embodiments of the present invention, a porous structure with a pore size of less than 300nm may be formed by hot alkali soaking, and at this time, the anodization process is adjusted to obtain a small pore structure with a pore size of 20-300nm on the basis of a large pore structure with a pore size of less than 300nm, which are nested with each other to form the above-mentioned porous oxide film. The specific parameters of the hot alkaline soak and the anodization are described in detail below.

The steps of the method are described in detail below with reference to specific examples of the present application. Referring to fig. 1, the method may include:

s100: providing a metal matrix and soaking the metal matrix in an inorganic alkaline solution

According to an embodiment of the present invention, in this step, the metal substrate is subjected to a soaking treatment in an inorganic alkaline solution. Inorganic reagents which are harmful to the environment are not added in the inorganic alkaline solution, for example, the inorganic alkaline solution does not contain reagents (such as hydrofluoric acid) containing halogen ions, so that on one hand, a more environment-friendly preparation method can be provided, on the other hand, reagents with overlarge toxic and side effects can be prevented from being introduced in the preparation process, and the risk of safety accidents of workers in the production process is reduced.

According to the specific embodiment of the present invention, the specific chemical composition of the inorganic alkaline solution used for soaking the metal substrate in this step is not particularly limited as long as the structure of the aforementioned macropores (or referred to as pits, for example, the pore diameter can be 100-30000nm) can be formed on the surface of the metal substrate, and those skilled in the art can select the inorganic alkaline solution according to the specific situation of the metal substrate. For example, titanium and alloys of titanium may be selected as the metal substrate. The inorganic alkaline solution may include at least one of a hydroxide of an alkali metal and a strong alkali and weak acid salt, and may be, for example, an aqueous solution of the above. For example, the inorganic alkaline solution may contain an inorganic strong base such as sodium hydroxide or potassium hydroxide. The concentration of the solute contained in the inorganic alkaline solution may be 250g to 400 g/L. For example, when the solute contained in the inorganic alkaline solution is an alkali metal hydroxide, the concentration of the solute may be 250 to 400g/L, for example, 280g/L, 300g/L, 350g/L, or the like. In some embodiments of the present invention, the concentration of hydroxide in the inorganic alkaline solution may be 100-170 g/L. When the solution contains a plurality of solutes, for example, two or more inorganic strong bases or strong base weak acid salts, the concentration of hydroxide radical in the inorganic alkaline solution can be controlled within the range of 100-170g/L by controlling the content of a plurality of solvents. Therefore, the macroporous structure can be formed under a moderate condition, on one hand, the situation that the environment for soaking treatment is too harsh and the metal matrix is excessively corroded due to the overlarge concentration of the inorganic alkaline solution can be avoided, and on the other hand, the situation that the macroporous structure can be formed only by soaking for a long time due to the overlow concentration of the inorganic alkaline solution can be prevented.

According to some embodiments of the present invention, in order to further improve the effect of the soaking treatment in this step, the inorganic alkaline solution may be heated during the soaking treatment, and the metal substrate may be soaked in the inorganic alkaline solution having a certain temperature. Specifically, when the soaking treatment is performed, the temperature of the inorganic alkaline solution may be 50 to 70 degrees celsius, and the soaking time may be 20 to 120 minutes.

Referring to fig. 2, in order to further improve the efficiency of the soaking process, before the soaking process, the soaking process may further include:

s10: polishing, degreasing and cleaning the metal substrate

According to an embodiment of the present invention, in this step, the metal base may be subjected to a grinding process, an oil removal process, and a first cleaning process in this order. Specifically, the metal substrate may be first subjected to a treatment including, but not limited to, physical grinding, polishing, etc. to remove hard impurities and relatively protruding protrusions from the surface of the metal substrate, and then subjected to a degreasing treatment in a cleaning solution to degrease the surface of the metal substrate. And finally, performing flowing water washing treatment to remove residual impurities on the surface of the metal matrix, and polishing solution, polishing powder, an oil removal reagent and the like which are remained during the previous polishing, grinding and oil removal treatment so as to ensure that the surface of the metal matrix has a clean and flat surface, thereby improving the soaking treatment efficiency on the one hand, and preventing different corrosion speeds at different positions due to the fact that the surface of the metal matrix is not flat or not clean enough and further influencing the subsequent combination with the resin material on the other hand.

Similarly, after the soaking treatment, in order to improve the effect of the subsequent anodizing treatment, before the anodizing treatment, the method may further include:

s20: performing a second cleaning process on the metal substrate subjected to the soaking process

According to an embodiment of the present invention, in this step, after the immersion treatment is performed on the metal base, a second cleaning treatment is performed on the metal base subjected to the immersion treatment, followed by a subsequent anodizing treatment. Therefore, the inorganic alkaline solution remained on the surface of the metal substrate after the soaking treatment can be removed through the second cleaning treatment, and the situation that the position is corroded too fast in the subsequent anodic oxidation process due to the local alkaline solution residue and the structure of the finally formed porous oxide film is influenced is prevented.

It should be noted that, in the present invention, the first cleaning process, the second cleaning process, and the like are only for distinguishing between a plurality of cleaning process operations, and cannot be understood as distinguishing between the importance of the two cleaning processes and the specific operations. The first cleaning process and the second cleaning process may be performed in the same or different manner, as long as impurities or residual reagents remaining on the surface of the metal substrate in the previous process step can be cleaned. For example, both cleaning processes may be performed using deionized water.

S200: anodizing the metal matrix subjected to the soaking treatment in an alkaline electrolyte

According to an embodiment of the present invention, in this step, the metal substrate having the macroporous structure formed on the surface thereof through the immersion treatment is subjected to an anodic oxidation treatment. Specifically, in this step, an alkaline electrolyte is used, and a metal substrate having macropores is used as an anode, and an anodic oxidation treatment is performed at a low voltage, so that a porous oxide film is formed on at least a part of the surface of the metal substrate. The porous oxide film is formed by opening the surface of the metal substrate and performing electrochemical treatment, and has a structure in which the large holes and the small holes are nested with each other, and the thickness, the pore diameters of the large holes and the small holes of the porous oxide film are described in detail above, and are not described again here.

Specifically, according to an embodiment of the present invention, the metal substrate is titanium or a titanium alloy, and in this step, the metal substrate may be used as an anode to perform an anodic oxidation treatment in an alkaline solution. The anodic oxidation treatment can be carried out at a voltage of 5-15V or at a voltage of 0.2-0.8A/dm²At a current density of (a). As will be appreciated by those skilled in the art, the anodization process is a process in which a metal substrate is used as an anode of an electrolytic cell and is subjected to an oxidation reaction in an alkaline electrolyte. The anodization process can be controlled by controlling the voltage applied to the anode (i.e., the metal substrate), or, if an inert cathode is selected, the current density of the anode during anodization can be controlled according to the specific composition and size of the inert cathode (e.g., Pt or Au electrode). Therefore, the anodization process may satisfy both the voltage and current density conditions, or one of the voltage and current density conditions. Therefore, a small pore structure with a proper pore diameter range can be formed on the surface of the metal matrix with the large pore structure, and the structure can improve the bonding force between the resin formed by the subsequent injection molding treatment and the metal matrix. Specifically, the prepared alkaline solution may be an inorganic alkaline solution, and may include, for example, potassium hydroxide, sodium hydroxideThe main alkaline solution, in order to ensure that the electrolyte can maintain a stable pH value during the anodic oxidation process, a buffer component, such as, but not limited to, EDTA, can be added to the electrolyte. The concentration of the inorganic base in the alkaline electrolyte can be 400-500 g/L. For example, the concentration may be 410-500g/L, such as 450g/L, 460g/L, 480g/L, etc. In order to further improve the efficiency of the anodic oxidation treatment, the alkaline electrolyte may also be subjected to a heating treatment in this step. For example, the solution temperature of the alkaline electrolyte may be set to 10 to 40 ℃. Under such conditions, the time for the anodic oxidation may be 5 to 30min, whereby the porous oxide film can be formed relatively easily.

According to an embodiment of the present invention, referring to fig. 2, after the anodizing treatment and before the resin is injection-molded, the method may further include:

s30: carrying out third cleaning treatment and drying treatment on the metal matrix

According to the embodiment of the present invention, in this step, the metal substrate on which the porous oxide film is formed through the anodic oxidation treatment is subjected to the third cleaning treatment and the baking treatment. Similarly, the third cleaning process may be performed by using deionized water, so as to remove the porous oxide film and the alkaline electrolyte remaining on the surface of the metal substrate. For example, the third cleaning treatment may be a water cleaning treatment. Subsequently, the metal substrate subjected to the third cleaning process may be subjected to a baking process, for example, may be baked at 60 ℃, and more specifically, the metal substrate may be placed in an oven to be baked.

S300: injection molding a resin at a position having the porous oxide film on the metal substrate

According to an embodiment of the present invention, a resin is injection-molded at a position having a porous oxide film on a metal substrate in this step to form the resin-metal composite. According to the embodiment of the present invention, the specific chemical composition of the resin material used for injection molding in this step is not particularly limited, and PPS, PBT, PA, etc. may be used for injection molding.

Specifically, for example, a plastic part having a certain shape can be formed by injection molding a plastic material (resin) at a specific position of a metal base using an injection mold, thereby obtaining a resin-metal composite.

According to an embodiment of the present invention, the position at which the injection molding is performed in this step is a position at which a porous oxide film is formed on the metal substrate. Therefore, the bonding force between the plastic part and the metal substrate can be improved by utilizing the structure that the large holes and the small holes of the porous oxide film are nested with each other. Specifically, the metal base may be a bar-shaped base, the porous oxide film may be formed at a sidewall of the metal base, and the injection-molded resin may be located at an end of the metal base. The formed resin-metal composite may have a structure as shown in fig. 4. Alternatively, the metal base may have a slit formed therethrough, the porous oxide film may cover at least a side wall of the slit, and the slit may be filled with an injection-molded resin. Thus, the resin-metal composite can be used as a shell of an electronic device, and the resin filled in the slit is used as an antenna slot of the shell, so that the metal shell is prevented from shielding communication signals. According to some embodiments of the present invention, the porous oxide film may cover the entire surface of the metal substrate, and the injection-molded resin may cover the entire surface of the metal substrate. For example, according to some embodiments of the present invention, the composite body formed by the above method may be a flat plate, a plate having a curved surface, or a tubular composite body.

In general, a method of preparing a resin-metal composite body according to an embodiment of the present invention has at least one of the following advantages:

1. alkaline liquid (such as sodium hydroxide, potassium hydroxide and the like) is used as a main body solution of the electrochemical anodic oxidation, and the components are nontoxic and environment-friendly.

2. The complex porous oxide film structure with nested macropores and micropores can be obtained by performing alkaline electrochemical treatment after hot alkali soaking, the bonding strength of the resin and the metal matrix can reach more than 32MPa, the bonding is stable, and the environmental test result is better.

3. The resin and the metal matrix have high bonding strength, can be used for forming complex structures, has a plurality of plastic choices, is suitable for various models of titanium and titanium alloy, and has wide application.

In yet another aspect of the present invention, a resin-metal composite is provided. The resin-metal complex comprises a metal matrix and an injection molding part, wherein at least part of the surface of the metal matrix is provided with a porous oxide film, and the porous oxide film comprises macropores with the pore diameter of 100-30000nm and micropores with the pore diameter of 20-300 nm. The injection part is formed of resin, and the injection part is located where the metal substrate has a porous oxide film. Therefore, the injection molding part can be filled into the porous oxide film, and the bonding force between the injection molding part and the metal substrate can be improved by utilizing the porous oxide film. Similarly, the porous oxide film has a structure of nesting large holes and small holes, so that the bonding between the injection molding part and the metal matrix can be enhanced, and the bonding strength of the resin and the metal matrix can reach more than 32 MPa.

It is to be specifically noted that in the resin-metal composite, the large pores and the small pores are formed by a two-step process, whereby the large pores and the small pores are formed in a nested structure to form a porous oxide film. Thus, when the specific parameters of the aforementioned two-step process are different, the pore sizes of the obtained macropores and micropores can be varied within the aforementioned ranges. In general, the resin-metal complex has a porous oxide film structure with the pore diameter ranging from 20 nm to 30000nm and the large pores and the small pores are nested with each other.

The resin-metal composite may be prepared using the method described above. Thus, the resin-metal composite can have all the features and advantages of the plate obtained by the method described above, and will not be described herein again. For example, the resin-metal composite may have an injection-molded part formed by injection-molding plastic, and a metal base. In some examples of the invention, the structure of the resin-metal composite may be as shown in fig. 4.

It is to be noted that the specific shape of the resin-metal composite body, and the specific shape and position of the injection molded part are not particularly limited as long as the injection molded part is formed at a position on the metal base body on the composite body having the above-mentioned porous oxide film. For example, the metal base may be a bar-shaped base, the porous oxide film may be formed at a sidewall of the metal base, and the injection molded part may be located at an end of the metal base. Alternatively, the metal base may have a slit formed therethrough, and the injection molded part may be filled in the slit. Alternatively, the porous oxide film may cover the entire surface of the metal substrate, and the injection molded part may cover the entire surface of the metal substrate. The composite may be a flat plate, a plate having a curved surface, or a tubular composite.

In yet another aspect of the present invention, a housing is presented. The housing includes the resin-metal composite described above. Thus, the housing may have all of the features and advantages of the previously described sheet material, which are not described in detail herein. For example, the housing may be a housing of an electronic device, wherein the metal base portion of the plate may serve as a base of the housing, and the injection-molded portion may serve as an antenna slot or an antenna seam of the housing, so as to prevent the metal base from shielding communication signals.

The present invention is illustrated below by way of specific examples, which are intended to be illustrative only and not to limit the scope of the present invention in any way, and reagents and materials used therein are commercially available, unless otherwise specified, and conditions or steps thereof are not specifically described.

Example 1

1. Preparing NaOH aqueous solution (I), wherein the concentration is 280g/L, dissolving and stirring a large amount of heat by using a PP (propene Polymer) tank, and placing in a constant-temperature water bath at 60 ℃ for later use.

2. Preparing NaOH aqueous solution (the concentration is 450 g/L), using a PP groove, dissolving and stirring a large amount of heated and static 2H, measuring the temperature by a thermometer at 26 ℃, and completely dissolving for later use.

3. The surface of a TA1 (3X 12X 40mm) metal substrate was ground by a grinder and then washed with degreasing water.

4. The TA1 metal matrix is first put into the prepared NaOH aqueous solution, soaked in a thermostatic water bath at 60 ℃ for 40min and then washed with water.

5. Then the TA1 metal matrix is put into the prepared NaOH aqueous solution II, the TA1 metal matrix is used as an anode, the constant voltage of a direct current power supply is 8V, and the water is washed and dried after the power is supplied for 20 min. The scanning electron micrograph of the formed porous oxide film is shown in FIG. 3.

6. And then the TA1 metal matrix is put into an injection molding machine for injection molding of PBT plastic, and a plastic part with the same size as the TA1 metal matrix is formed at the end of the TA1 metal matrix, and the structural schematic diagram is shown in FIG. 4. The pull-out force was measured on a universal tester after molding, and the test results are shown in table 1 below.

Example 2

1. Preparing NaOH aqueous solution (I), wherein the concentration is 280g/L, dissolving and stirring a large amount of heat by using a PP (propene Polymer) tank, and placing in a constant-temperature water bath at 60 ℃ for later use.

2. Preparing NaOH aqueous solution (the concentration is 450 g/L), using a PP groove, dissolving and stirring a large amount of heated and static 2H, measuring the temperature by a thermometer at 26 ℃, and completely dissolving for later use.

3. The surface of a TA2 (3X 12X 40mm) metal substrate was ground by a grinder and then washed with degreasing water.

4. The TA2 metal matrix is first put into the prepared NaOH aqueous solution, soaked in a thermostatic water bath at 60 ℃ for 40min and then washed with water.

5. Then the TA2 metal matrix is put into the prepared NaOH aqueous solution II, the TA2 metal matrix is used as an anode, the constant voltage of a direct current power supply is 10V, and the water is washed and dried after the power is supplied for 20 min.

6. And then the TA2 metal matrix is put into an injection molding machine for injection molding of PBT plastic, and a plastic part with the same size as the TA2 metal matrix is formed at the end of the TA2 metal matrix, and the structural schematic diagram is shown in FIG. 4. The pull-out force was measured on a universal tester after molding, and the test results are shown in table 1 below.

Embodiment 3

1. Preparing NaOH aqueous solution (I), wherein the concentration is 280g/L, dissolving and stirring a large amount of heat by using a PP (propene Polymer) tank, and placing in a constant-temperature water bath at 60 ℃ for later use.

2. Preparing NaOH aqueous solution (the concentration is 450 g/L), using a PP groove, dissolving and stirring a large amount of heated and static 2H, measuring the temperature by a thermometer at 26 ℃, and completely dissolving for later use.

3. The surface of TC4 (3X 12X 40mm) metal substrate was ground by a grinder and then washed with degreasing water.

4. Firstly, putting a TC4 metal matrix into a prepared NaOH aqueous solution I, soaking in a constant-temperature water bath at 60 ℃ for 40min, and then washing with water.

5. Then putting the TC4 metal matrix into a prepared NaOH aqueous solution II, taking the TC4 metal matrix as an anode, keeping the voltage of the direct current power supply constant at 10V, electrifying for 20min, and then washing and drying.

6. And then, the TC4 metal matrix is placed into an injection molding machine for injection molding of PBT plastic, and a plastic part with the same size as the TC4 metal matrix is formed at the end of the TC4 metal matrix, wherein the structural schematic diagram is shown in FIG. 4.

The pull-out force was measured on a universal tester after molding, and the test results are shown in table 1 below.

The molded resin-metal composite was subjected to environmental testing and then the drawing force was measured, and the test results are shown in table 2.

Example 4

The other steps are the same as the example 3, except that NaOH aqueous solution (I) is prepared during the hot alkali soaking, the concentration is 250g/L, and the NaOH aqueous solution is used for soaking the metal matrix after being subjected to constant-temperature water bath at 60 ℃. The drawing force was measured on a universal tester after injection molding, and the test results are shown in table 1 below.

Example 5

The other steps are the same as the example 3, except that NaOH aqueous solution (i) is prepared during the hot alkali soaking, the concentration is 300g/L, and the NaOH aqueous solution is used for soaking the metal matrix after being subjected to constant-temperature water bath at 60 ℃. The drawing force was measured on a universal tester after injection molding, and the test results are shown in table 1 below.

Example 6

The other steps are the same as the example 3, except that NaOH aqueous solution (i) is prepared during the hot alkali soaking, the concentration is 350g/L, and the NaOH aqueous solution is used for soaking the metal matrix after being subjected to constant-temperature water bath at 60 ℃. The drawing force was measured on a universal tester after injection molding, and the test results are shown in table 1 below.

Example 7

The rest steps are the same as the example 3, except that NaOH aqueous solution II with the concentration of 400g/L is prepared, the NaOH aqueous solution is electrochemical anodic oxidation electrolyte, the constant voltage of a direct current power supply is 12V, and the NaOH aqueous solution is washed by water and dried after being electrified for 20 min. The drawing force was measured on a universal tester after injection molding, and the test results are shown in table 1 below.

Example 8

The rest steps are the same as the example 3, except that a NaOH aqueous solution is prepared, the concentration is 420g/L, the NaOH aqueous solution is electrochemical anodic oxidation electrolyte, the constant voltage of a direct current power supply is 12V, and the NaOH aqueous solution is washed by water and dried after being electrified for 20 min. The drawing force was measured on a universal tester after injection molding, and the test results are shown in table 1 below.

Example 9

The rest steps are the same as the example 3, except that a NaOH aqueous solution is prepared, the concentration is 480g/L, the NaOH aqueous solution is electrochemical anodic oxidation electrolyte, the constant voltage of a direct current power supply is 6V, and the NaOH aqueous solution is washed by water and dried after being electrified for 20 min. The drawing force was measured on a universal tester after injection molding, and the test results are shown in table 1 below.

Embodiment 10

The rest steps are the same as the example 3, except that NaOH aqueous solution II with the concentration of 500g/L is prepared, the NaOH aqueous solution is electrochemical anodic oxidation electrolyte, the constant voltage of a direct current power supply is 6V, and the NaOH aqueous solution is washed by water and dried after being electrified for 20 min. The drawing force was measured on a universal tester after injection molding, and the test results are shown in table 1 below.

Comparative example 1

1. Preparing a sulfuric acid aqueous solution (i) with the concentration of 100g/L, dissolving and stirring a large amount of the sulfuric acid aqueous solution by using a PP (polypropylene) tank, heating and standing for 2H, measuring the temperature by using a thermometer, and completely dissolving the sulfuric acid aqueous solution for later use.

2. Preparing NaOH aqueous solution (the concentration is 200 g/L), using a PP groove, dissolving and stirring a large amount of the NaOH aqueous solution, heating and standing for 2H, measuring the temperature by a thermometer to be 26 ℃, and completely dissolving the NaOH aqueous solution for later use.

3. The surface of TC4 (3X 12X 40mm) metal substrate was ground by a grinder and then washed with degreasing water.

4. Putting a TC4 metal matrix into a prepared sulfuric acid aqueous solution I, taking a TC4 metal matrix as a cathode, powering on for 10min by using a direct-current power supply with constant voltage of 20V, and washing by using water.

5. Putting a TC4 metal matrix into a prepared NaOH aqueous solution II, taking a TC4 metal matrix as an anode, keeping the voltage of a direct current power supply constant at 20V, electrifying for 10min, and washing and drying.

6. The TC4 metal matrix is placed into an injection molding machine for injection molding of PBT plastic, a plastic part with the same size as the TC4 metal matrix is formed at the end of the TC4 metal matrix, and the structural schematic diagram is shown in FIG. 4. The pull-out force was measured on a universal tester after molding, and the test results are shown in table 1 below.

Comparative example 2

1. Preparing NaOH aqueous solution with the concentration of 280g/L, using a PP tank, dissolving and stirring a large amount of the solution, heating and standing for 2H, measuring the temperature by a thermometer to be 26 ℃, and completely dissolving the solution for later use.

2. The surface of TC4 (3X 12X 40mm) metal substrate was ground by a grinder and then washed with degreasing water.

3. Putting a TC4 metal matrix into a prepared NaOH aqueous solution, taking a TC4 metal matrix as an anode, keeping the voltage of the DC power supply constant at 10V, electrifying for 20min, and washing and drying.

4. The TC4 metal matrix is placed into an injection molding machine for injection molding of PBT plastic, a plastic part with the same size as the TC4 metal matrix is formed at the end of the TC4 metal matrix, and the structural schematic diagram is shown in FIG. 4. The pull-out force was measured on a universal tester after molding, and the test results are shown in table 1 below.

Comparative example 3

1. Preparing NaOH aqueous solution with the concentration of 450g/L, dissolving and stirring a large amount of the NaOH aqueous solution by using a PP (polypropylene) tank, heating and standing for 2H, measuring the temperature by using a thermometer at 26 ℃, and completely dissolving the NaOH aqueous solution for later use.

2. The surface of TC4 (3X 12X 40mm) metal substrate was ground by a grinder and then washed with degreasing water.

3. Putting a TC4 metal matrix into a prepared NaOH aqueous solution, taking a TC4 metal matrix as an anode, keeping the voltage of the DC power supply constant at 10V, electrifying for 20min, and washing and drying.

4. The TC4 metal matrix is placed into an injection molding machine for injection molding of PBT plastic, a plastic part with the same size as the TC4 metal matrix is formed at the end of the TC4 metal matrix, and the structural schematic diagram is shown in FIG. 4. The pull-out force was measured on a universal tester after molding, and the test results are shown in table 1 below.

Comparative example 4

1. Preparing NaOH aqueous solution with the concentration of 280g/L, dissolving and stirring a large amount of heat by using a PP tank, and placing in a constant-temperature water bath at 60 ℃ for standby.

2. The surface of TC4 (3X 12X 40mm) metal substrate was ground by a grinder and then washed with degreasing water.

3. Putting the TC4 metal matrix into the prepared NaOH aqueous solution, soaking in a constant-temperature water bath at 60 ℃ for 120min, and then washing and drying.

4. The TC4 metal matrix is placed into an injection molding machine for injection molding of PBT plastic, a plastic part with the same size as the TC4 metal matrix is formed at the end of the TC4 metal matrix, and the structural schematic diagram is shown in FIG. 4. The pull-out force was measured on a universal tester after molding, and the test results are shown in table 1 below.

Comparative example 5

The other steps are the same as example 3, except that a NaOH aqueous solution (i) with the concentration of 100g/L is prepared for soaking the TC4 metal matrix. The test results are shown in table 1 below.

Comparative example 6

The rest steps are the same as the example 3, except that NaOH aqueous solution II with the concentration of 200g/L is prepared, the NaOH aqueous solution is electrochemical anodic oxidation electrolyte, the constant voltage of a direct current power supply is 10V, and the NaOH aqueous solution is washed by water and dried after being electrified for 20 min. The drawing force was measured on a universal tester after injection molding, and the test results are shown in table 1 below.

Comparative example 7

The rest steps are the same as the example 3, except that NaOH aqueous solution II is prepared, the concentration is 600g/L and is electrochemical anodic oxidation electrolyte, the constant voltage of a direct current power supply is 10V, and the water is washed and dried after the power is supplied for 20 min. The drawing force was measured on a universal tester after injection molding, and the test results are shown in table 1 below.

Comparative example 8

The rest steps are the same as the example 3, except that NaOH aqueous solution II is prepared, the concentration is 450g/L, electrochemical anodic oxidation electrolyte is prepared, the constant voltage of a direct current power supply is 20V, and the water is washed and dried after the power is supplied for 20 min. The drawing force was measured on a universal tester after injection molding, and the test results are shown in table 1 below.

The test equipment for the drawing test is a universal tester, the tensile speed is 5mm/min, and the unit MPa (acting on the unit area (m)²) Force (N) above).

TABLE 1

As is clear from the test results in Table 1, all the examples of the present application have a pull strength of 34MPa or more.

Table 2 environmental test results

As is clear from the test results in Table 2, the pull-out strength was not significantly decreased after the reliability test.

In the description of the present invention, the terms "upper", "lower", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of describing the present invention but do not require that the present invention must be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.

In the description herein, references to the description of "one embodiment," "another embodiment," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction. In addition, it should be noted that the terms "first" and "second" in this specification are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any number of technical features indicated.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.