CN112406007B - Resin-metal composite and method of making, and housing - Google Patents

Abstract

The invention discloses a resin-metal composite body, a preparation method, and a casing. The method includes: providing a metal substrate, and immersing the metal substrate in an inorganic alkaline solution; and performing anodizing treatment on the metal substrate after the immersion treatment in an alkaline electrolyte, so as to be in the alkaline electrolyte. A porous oxide film is formed on at least part of the surface of the metal base; and resin is injected at the position where the porous oxide film is formed on the metal base to form the resin-metal composite. The method can utilize environmentally friendly reagents to treat the metal matrix, and the finally obtained resin-metal composite has strong bonding strength between the resin and the metal.

Description

Resin-metal composite and method of making, and housing

technical field

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

Background technique

Titanium and titanium alloys are light in weight, high in specific strength, have strong mechanical properties, good corrosion resistance and fatigue resistance. The thermal stability and corrosion resistance of titanium alloy are much better than that of aluminum alloy, and after polishing, the gloss is higher than that of aluminum alloy, which is close to the luster of stainless steel. Therefore, titanium and titanium alloys have broad application prospects in the field of shells and internal components of electronic products (such as mobile phones, notebook computers, tablets, etc.), and are increasingly favored by mobile phone terminal manufacturers. In order to solve the shielding of the signal by the casing made of metal (such as the aforementioned titanium and titanium alloy), it is usually necessary to open a slot in the metal casing, and fill the non-conductive material to form the antenna slot. For example, at present, the shell can be formed by using a metal and plastic integrated board. For example, titanium and titanium alloys can be surface-treated, and then in-mold injection molding can be performed to form structures such as plastic antenna slits.

However, current resin-metal composites and preparation methods, as well as shells, still need to be improved.

SUMMARY OF THE INVENTION

The present invention is made based on the inventors' findings and understanding of the following facts and problems:

As mentioned above, in order to prevent the all-metal casing from shielding the signal, a resin-metal composite body is usually used to form the casing. To enhance the bond between the injection-molded plastic and the metal matrix, the metal surface is usually first treated before injection. At present, the commonly used techniques for surface treatment of titanium and titanium alloys mainly include acid corrosion and alkaline electrochemistry. The acid is mainly corroded by hydrofluoric acid, hydrochloric acid, etc. as the main solution, so that holes are formed on its surface, so that the plastic can enter the hole to enhance the bonding force during molding, or through the electrochemical method using hydrofluoric acid as the main solution. A porous film is formed on the surface of titanium and titanium alloys, which also enhances the bonding force between titanium and titanium alloys and plastics. Although this method can improve the bonding strength of titanium and titanium alloys, it is often necessary to add organic additives or halide ions to the solution used, which causes great environmental pollution and high cost of sewage treatment, which is not suitable for large-scale production. In addition, hydrofluoric acid is too corrosive and harmful to human body, which is not conducive to industrial production. Although the existing alkaline electrochemical treatment can alleviate the problem of environmental pollution, the composite formed by the existing alkaline method has low bonding strength. Therefore, if an environment-friendly preparation method with reliable bonding strength can be provided, the above-mentioned technical problems will be greatly alleviated or even solved.

In view of this, in one aspect of the present invention, the present invention provides a method for preparing a resin-metal composite. The method includes: providing a metal substrate, and immersing the metal substrate in an inorganic alkaline solution; and performing anodizing treatment on the metal substrate after the immersion treatment in an alkaline electrolyte, so that the A porous oxide film is formed on at least a part of the surface of the metal base; and resin is injected at the position where the porous oxide film is formed on the metal base to form the resin-metal composite. The method can use environmentally friendly reagents to treat the metal matrix, and the finally obtained resin-metal composite has strong bonding strength between the resin and the metal.

In another aspect of the present invention, the present invention provides a resin-metal composite. The resin-metal composite includes a metal matrix, at least part of the surface of the metal matrix has a porous oxide film, the porous oxide film includes large pores with a pore size of 100-30000 nm and small pores with a pore size of 20-300 nm; and injection molding The injection part is formed of resin, and the injection part is located on the metal base where the porous oxide film is formed. In general, the board has at least one of the advantages of low production cost, less environmental pollution, and reliable bonding strength.

In yet another aspect of the present invention, the present invention provides a casing. The housing includes the resin-metal composite described above. Thus, the housing has all the features and advantages of the composite body described above, which will not be repeated here. In general, the housing has at least one of the advantages of low production cost, environmentally friendly preparation process, and long service life.

Description of drawings

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

FIG. 1 shows a schematic flowchart of a method for preparing a resin-metal composite according to an embodiment of the present invention;

FIG. 2 shows a schematic flowchart of a method for preparing a resin-metal composite according to another embodiment of the present invention;

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

FIG. 4 shows a schematic structural diagram of a resin-metal composite according to an embodiment of the present invention.

Detailed ways

The following describes in detail the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals refer to the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary, only used to explain the present invention, and should not be construed as a limitation of the present invention.

In one aspect of the present invention, the present invention provides a method for preparing a resin-metal composite. Specifically, the present invention adopts the method of soaking with hot alkali, firstly, densely distributed pits with larger size are formed on the metal substrate (for example, the surface of titanium and titanium alloys), and the width of the pits can be 100-30000nm In the range. Then, electrochemical treatment is carried out in the electrolyte with alkaline solution as the main body, such as low-pressure anodic oxidation treatment, so as to form large pores, small pores on the surface of titanium and titanium alloys with pits (macropores) on the surface. Porous oxide films with nested pores and complex microstructures. The pore size of the pores formed by the anodization process may be 20-300 nm, and the film thickness of the porous oxide film may be between 100-500 nm. Thereby, the surface of the obtained metal substrate can be formed with a layer of 100-500nm thick macropores of about 100-30000nm, and a complex structure of small pores with pore diameters of 20-300nm nested in the macropores. After the metal matrix with this structure is injection-molded in the mold, a high bonding strength can be achieved between the metal matrix and the plastic, and the bonding strength can reach more than 32MPa. Furthermore, a relatively complex structure can be formed on the metal matrix by injection molding, and various materials (such as PPS, PBT, PA, etc.) can be formed with the metal matrix by injection molding to form a resin-metal composite body. In general, the method has at least one of the advantages of simple process conditions, strong operability, and no pollution to the environment during the treatment process.

It should be noted here that the "large pores" mentioned in this application are formed during the hot alkali soaking process, and the "small pores" are formed during the anodizing process. Therefore, when the parameters of the hot alkali soaking treatment and the anodizing treatment are different, the specific pore size range of the large pores and the specific pore size range of the small pores are also different. For example, in some embodiments of the present invention, a pore-like structure with a pore diameter of less than 300 nm can be formed by soaking in hot alkali. At this time, the anodic oxidation process can be adjusted to obtain a macroporous structure with a pore diameter of less than 300 nm on the basis of a pore diameter of 20 nm. -300nm small pore structure, the two are nested in each other to form the above-mentioned porous oxide film. The specific parameters of hot alkali soaking and anodizing will be described in detail below.

Each step of the method will be described in detail below with reference to the specific embodiments of the present application. Referring to Figure 1, the method may include:

S100: providing a metal matrix, and immersing the metal matrix in an inorganic alkaline solution

According to an embodiment of the present invention, in this step, the metal substrate is soaked in an inorganic alkaline solution. The inorganic alkaline solution used in the present invention does not add inorganic reagents that are more harmful to the environment, for example, does not contain reagents including but not limited to halide ions (such as hydrofluoric acid), so on the one hand, it can provide an environmental friendly The more friendly preparation method, on the other hand, can prevent the introduction of reagents with excessive toxic and side effects in the preparation process, and reduce the risk of safety accidents for workers during the production process.

According to specific embodiments of the present invention, the specific chemical composition of the inorganic alkaline solution used to soak the metal substrate in this step is not particularly limited, as long as the aforementioned macropores (or pits, such as pore diameters) can be formed on the surface of the metal substrate It can be a structure of 100-30000 nm), and those skilled in the art can choose according to the specific conditions of the metal matrix. For example, titanium and titanium alloys can be selected as the metal matrix. The inorganic alkaline solution may include at least one of alkali metal hydroxides and strong bases and weak acid salts, and may be, for example, aqueous solutions of the above substances. For example, the inorganic alkaline solution may contain inorganic strong bases such as sodium hydroxide and potassium hydroxide. The concentration of the solute contained in the inorganic alkaline solution may be 250 g 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 can be 250-400 g/L, for example, 280 g/L, 300 g/L, 350 g/L and 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 multiple solutes, such as two or more inorganic strong bases, or strong bases and weak acid salts, the concentration of hydroxide in the inorganic alkaline solution can be controlled by controlling the content of multiple solvents. in the range of 100-170g/L. As a result, a macroporous structure can be formed under relatively moderate conditions. On the one hand, it can avoid the excessive concentration of the inorganic alkaline solution, which leads to the harsh environment of the immersion treatment and causes excessive corrosion to the metal matrix. On the other hand, it can also prevent the inorganic alkali from being too high. The concentration of the reactive solution is too low, resulting in the need for long soaking to form a macroporous structure.

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 matrix may be soaked in the inorganic alkaline solution having a certain temperature. deal with. Specifically, during the soaking treatment, the temperature of the inorganic alkaline solution may be 50-70 degrees Celsius, and the soaking time may be 20-120 minutes.

Referring to FIG. 2 , in order to further improve the efficiency of the soaking treatment, before the soaking treatment is performed, it may also include:

S10: Perform grinding treatment, degreasing treatment and first cleaning treatment on the metal substrate

According to an embodiment of the present invention, in this step, the metal substrate may be subjected to a grinding process, a degreasing process, and a first cleaning process in sequence. Specifically, the metal substrate may be first subjected to treatments including but not limited to physical grinding, polishing, etc. to remove hard impurities and relatively prominent protrusions on the surface of the metal substrate, and then degreasing treatment is performed in a cleaning solution to remove the metal substrate. Oil stains on the surface. Finally, a flowing water washing treatment is performed to remove the residual impurities on the surface of the metal substrate, as well as the polishing liquid, polishing powder and degreasing agent remaining in the previous polishing, grinding and degreasing treatment, so that the surface of the metal substrate has a clean and flat surface. Therefore, on the one hand, it can improve the efficiency of the soaking treatment, and on the other hand, it can also prevent the corrosion rate at different positions from being different due to the unevenness or insufficient cleaning of the metal substrate surface, thereby affecting the subsequent combination with the resin material.

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: Perform a second cleaning treatment on the metal substrate subjected to the soaking treatment

According to an embodiment of the present invention, in this step, after the soaking treatment is performed on the metal substrate, a second cleaning treatment is performed on the metal substrate after the soaking treatment, and then a subsequent anodizing treatment is performed . In this way, the inorganic alkaline solution remaining on the surface of the metal substrate can be removed by the second cleaning treatment, so as to prevent the local alkaline solution from being left to cause excessive corrosion of the position in the subsequent anodizing process, affecting the final formation structure of the porous oxide film.

It should be noted here that, in the present invention, the first cleaning treatment, the second cleaning treatment, etc. are only for distinguishing multiple cleaning treatment operations, and cannot be understood as the importance or specific operations of the two cleaning treatments. difference. The specific operations of the first cleaning treatment and the second cleaning treatment may be the same or different, as long as the impurities or residual reagents remaining on the surface of the metal substrate in the previous treatment step can be cleaned. For example, both cleaning treatments may be performed with deionized water.

S200: Perform anodizing treatment on the metal substrate subjected to the soaking treatment in an alkaline electrolyte

According to an embodiment of the present invention, in this step, anodizing treatment is performed on the metal substrate having the macroporous structure formed on the surface after the soaking treatment. Specifically, in this step, an alkaline electrolyte is used, a metal substrate with macropores is used as an anode, and anodization is performed at a relatively low voltage, so as to form a porous oxide film on at least part of the surface of the metal substrate. Porous oxide film is a porous oxide film with macropore and small hole nested structure formed by electrochemical treatment on the surface of the aforementioned open metal substrate. It has been described in detail and will not be repeated here.

Specifically, according to a specific embodiment of the present invention, taking the metal substrate as titanium or a titanium alloy as an example, in this step, the metal substrate can be used as an anode, and anodizing treatment can be performed in an alkaline solution. The anodizing treatment can be carried out at a voltage of 5-15V, or at a current density of 0.2-0.8A/dm ² . It can be understood by those skilled in the art that the anodic oxidation process is a process in which the metal matrix is used as the anode of the electrolytic cell to undergo an oxidation reaction in an alkaline electrolyte. The anodic oxidation process can be controlled by controlling the voltage applied to the anode (that is, the metal substrate), or, when an inert cathode is selected, it can also be controlled according to the specific composition and size of the inert cathode (such as Pt or Au electrode). Control the current density of the anode during anodization. Therefore, the anodization process can satisfy the above-mentioned voltage and current density conditions at the same time, or can satisfy either of the above-mentioned voltage conditions and current density conditions. As a result, a small pore structure with an appropriate pore size range can be formed on the surface of the metal matrix having the macroporous structure, and the structure can improve the bonding force between the resin and the metal matrix formed by the subsequent injection molding process. Specifically, the prepared alkaline solution can be an inorganic alkaline solution, such as an alkaline solution based on potassium hydroxide and sodium hydroxide. In order to ensure that the electrolyte can maintain a stable pH value during the anodic oxidation process, the Buffer components can also be appropriately added to the electrolyte, for example, buffer reagents including but not limited to EDTA can be added. The concentration of the inorganic base in the alkaline electrolyte may be 400-500 g/L. For example, it can be 410-500 g/L, such as 450 g/L, 460 g/L, 480 g/L, and the like. In order to further improve the efficiency of the anodizing treatment, the alkaline electrolyte can also be heated in this step. For example, the solution temperature of the alkaline electrolyte can be set to 10-40°C. Under this condition, the time of anodic oxidation can be 5-30min, thus, 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 injection molding, the method may further include:

S30: Perform a third cleaning treatment and a drying treatment on the metal substrate

According to an embodiment of the present invention, in this step, a third cleaning treatment and a drying treatment are performed on the metal substrate formed with the porous oxide film after the anodization treatment. Similarly, the third cleaning treatment can also be performed with deionized water, in order to remove the porous oxide film and the residual alkaline electrolyte on the surface of the metal substrate. For example, the third washing process may be a water washing process. Subsequently, the metal substrate subjected to the third cleaning treatment may be dried, for example, dried at 60° C., and more specifically, the metal substrate may be dried in an oven.

S300: Injection molding resin at the position of the porous oxide film on the metal substrate

According to an embodiment of the present invention, in this step, resin is injection-molded at the position of the porous oxide film on the metal substrate 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, for example, PPS, PBT, PA, etc. can be used for injection molding.

For example, specifically, an injection mold can be used to form a plastic part having a certain shape by injection molding a plastic material (resin) at a specific position of the metal matrix, thereby obtaining a resin-metal composite body.

According to an embodiment of the present invention, the position where the injection molding is performed in this step is the position where the porous oxide film is formed on the metal substrate. Therefore, the structure in which the large pores and the small pores are nested in the porous oxide film can be used to improve the bonding force between the plastic part and the metal substrate. Specifically, the metal base may be a strip-shaped base, the porous oxide film may be formed at the sidewall of the metal base, and the injection-molded resin may be located at the 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 slits penetrating the metal base, the porous oxide film may cover at least the sidewalls of the slits, and the injection-molded resin is filled in the slits. Therefore, the resin-metal composite body can serve as a casing of an electronic device, and the resin filled in the slit is used as an antenna slot of the casing, so as to prevent the metal casing from shielding communication signals. According to some embodiments of the present invention, the porous oxide film may also cover the entire surface of the metal substrate, and the injection-molded resin may also cover the entire surface of the metal substrate. For example, according to some specific embodiments of the present invention, the composite formed by the above method may be a flat plate, a plate with a curved surface, or a tubular composite.

In general, the method for preparing a resin-metal composite 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, etc.) is used as the main solution for electrochemical anodic oxidation. The composition is non-toxic and environmentally friendly.

2. After soaking in hot alkali and performing alkaline electrochemical treatment, a complex porous oxide film structure with large pores and small pores can be obtained. The bonding strength of resin and metal matrix can reach more than 32MPa, and the bonding is stable, and the environmental test results are relatively high. it is good.

3. The resin and the metal matrix have high bonding strength, which can be used for complex structure molding. There are many choices of plastics, and various types of titanium and titanium alloys are suitable for a wide range of uses.

In yet another aspect of the present invention, the present invention provides a resin-metal composite. The resin-metal composite body includes a metal matrix and an injection molding part. At least part of the surface of the metal matrix has a porous oxide film. The porous oxide film includes large pores with a pore size of 100-30000 nm and small pores with a pore size of 20-300 nm. The injection part is formed of resin, and the injection part is located where the metal base has a porous oxide film. Therefore, the injection molding part can be filled into the inside of the porous oxide film, and then the bonding force between the injection molding part and the metal substrate can be improved by using the porous oxide film. In general, the plate has the advantages of low production cost, less environmental pollution, At least one of the advantages of reliable bonding strength. Similarly, the porous oxide film has a structure of large pores and small pores nesting, which can enhance the bonding between the injection part and the metal matrix, and the bonding strength between the resin and the metal matrix can reach more than 32MPa.

It should be noted here that in this resin-metal composite, the macropores and the small pores are formed by a two-step process, so that the macropores and the small pores form a mutually nested structure, thereby forming a porous oxide. membrane. Therefore, when the specific parameters of the aforementioned two-step process are different, the pore diameters of the obtained macropores and small pores can vary within the aforementioned range. In general, the resin-metal composite has a pore size range of 20-30,000 nm, and a porous oxide film structure in which macropores and small pores are nested within each other is sufficient.

The resin-metal composite may be prepared using the methods previously described. Therefore, the resin-metal composite body can have all the features and advantages of the sheet obtained by the method described above, which will not be repeated here. For example, the resin-metal composite may have an injection molded portion formed by injection molding plastic, and a metal matrix. In some examples of the present invention, the structure of the resin-metal composite may be as shown in FIG. 4 .

It should be noted that the specific shape of the resin-metal composite body and the specific shape and position of the injection part are not particularly limited, as long as the injection part is formed at the position where the above-mentioned porous oxide film is formed on the metal matrix on the composite body . For example, the metal base may be a strip-shaped base, the porous oxide film may be formed at the sidewall of the metal base, and the injection molding part may be located at the end of the metal base. Alternatively, the metal base may have slits penetrating through the metal base, and the injection-molded part may be filled in the slits. Alternatively, the porous oxide film may also cover the entire surface of the metal substrate, and the injection molding portion may also cover the entire surface of the metal substrate. The composite body can be a flat plate, a plate with a curved surface, or a tubular composite body.

In yet another aspect of the present invention, the present invention provides a casing. The housing includes the resin-metal composite described above. Therefore, the housing can have all the features and advantages of the above-mentioned board, which will not be repeated here. For example, the casing can be a casing of an electronic device, wherein the metal base part of the plate can be used as the base of the casing, and the injection molded part can be used as an antenna slot or an antenna slot of the casing to prevent the metal base from shielding communication signals.

The present invention will be described below through specific embodiments. It should be noted that the following specific embodiments are only for the purpose of illustration, and do not limit the scope of the present invention in any way. In addition, unless otherwise specified, conditions are not specifically described Or the methods of the steps are all conventional methods, and the reagents and materials used can be obtained from commercial sources.

Implementation Case 1

1. Prepare an aqueous NaOH solution①, the concentration is 280g/L, use a PP tank, dissolve and stir to generate a lot of heat, and put it in a 60°C constant temperature water bath for use.

2. Prepare an aqueous NaOH solution ② with a concentration of 450 g/L, use a PP tank, dissolve and stir a large amount of heat and stand still for 2 hours, and then measure the temperature at 26°C with a thermometer, and use it after it is completely dissolved.

3. Grind the surface of the TA1 (3×12×40mm) metal substrate with a grinder, and then perform degreasing and water washing.

4. First put the TA1 metal matrix into the prepared NaOH aqueous solution ①, soak it in a constant temperature water bath at 60°C for 40 minutes, and then wash it with water.

5. Then put the TA1 metal matrix into the prepared NaOH aqueous solution ②, the TA1 metal matrix is used as the anode, the constant voltage of the DC power supply is 8V, and after energizing for 20 minutes, it is washed and dried. A scanning electron microscope photograph of the formed porous oxide film is shown in FIG. 3 .

6. Then put the TA1 metal base into the injection molding machine to inject PBT plastic, and form a plastic part with the same size as the TA1 metal base at the end of the TA1 metal base. The schematic diagram is shown in Figure 4. After forming, the pull-out force was tested on a universal testing machine, and the test results are shown in Table 1 below.

Implementation case 2

1. Prepare an aqueous NaOH solution①, the concentration is 280g/L, use a PP tank, dissolve and stir to generate a lot of heat, and put it in a 60°C constant temperature water bath for use.

2. Prepare an aqueous NaOH solution ② with a concentration of 450 g/L, use a PP tank, dissolve and stir a large amount of heat and stand still for 2 hours, and then measure the temperature at 26°C with a thermometer, and use it after it is completely dissolved.

3. Grind the surface of the TA2 (3×12×40mm) metal substrate with a grinder, and then perform degreasing and water washing.

4. First put the TA2 metal matrix into the prepared NaOH aqueous solution ①, soak it in a constant temperature water bath at 60°C for 40 minutes, and then wash it with water.

5. Then put the TA2 metal matrix into the prepared NaOH aqueous solution ②, the TA2 metal matrix is used as the anode, the constant voltage of the DC power supply is 10V, and it is washed and dried after being electrified for 20 minutes.

6. Then put the TA2 metal base into the injection molding machine to inject PBT plastic, and form a plastic part with the same size as the TA2 metal base at the end of the TA2 metal base. The schematic diagram is shown in Figure 4. After forming, the pull-out force was tested on a universal testing machine, and the test results are shown in Table 1 below.

Implementation Case 3

1. Prepare an aqueous NaOH solution①, the concentration is 280g/L, use a PP tank, dissolve and stir to generate a lot of heat, and put it in a 60°C constant temperature water bath for use.

2. Prepare an aqueous NaOH solution ② with a concentration of 450 g/L, use a PP tank, dissolve and stir a large amount of heat and stand still for 2 hours, and then measure the temperature at 26°C with a thermometer, and use it after it is completely dissolved.

3. Grind the surface of the TC4 (3×12×40mm) metal substrate with a grinder, and then perform degreasing and water washing.

4. First put the TC4 metal matrix into the prepared NaOH aqueous solution①, soak it in a constant temperature water bath at 60°C for 40min, and then wash it with water.

5. Then put the TC4 metal matrix into the prepared NaOH aqueous solution ②, the TC4 metal matrix is used as the anode, the constant voltage of the DC power supply is 10V, and it is washed and dried after being electrified for 20 minutes.

6. Then put the TC4 metal base into the injection molding machine to inject PBT plastic, and form a plastic part with the same size as the TC4 metal base at the end of the TC4 metal base. The schematic diagram is shown in Figure 4.

After forming, the pull-out force was tested on a universal testing machine, and the test results are shown in Table 1 below.

The formed resin-metal composite body was subjected to the environmental test synchronously, and then the pull-out force was tested. The test results are shown in Table 2.

Implementation Case 4

The rest of the steps are the same as those in Example 3, the difference is that the NaOH aqueous solution ① is prepared during the hot alkali soaking, the concentration is 250g/L, and the 60°C constant temperature water bath is used to soak the metal substrate. After injection molding, the pull-out force was tested on a universal testing machine, and the test results are shown in Table 1 below.

Implementation Case 5

The rest of the steps are the same as in Example 3, the difference is that a NaOH aqueous solution ① is prepared during the hot alkali soaking, the concentration is 300g/L, and the 60°C constant temperature water bath is used to soak the metal matrix. After injection molding, the pull-out force was tested on a universal testing machine, and the test results are shown in Table 1 below.

Implementation Case 6

The remaining steps are the same as those in Example 3, the difference is that the NaOH aqueous solution ① is prepared during the hot alkali soaking, the concentration is 350g/L, and the 60°C constant temperature water bath is used to soak the metal substrate. After injection molding, the pull-out force was tested on a universal testing machine, and the test results are shown in Table 1 below.

Implementation Case 7

The remaining steps are the same as in Example 3, the difference is that the NaOH aqueous solution ② is prepared with a concentration of 400 g/L, which is an electrochemical anodic oxidation electrolyte, and the constant voltage of the DC power supply is 12V. After injection molding, the pull-out force was tested on a universal testing machine, and the test results are shown in Table 1 below.

Implementation Case 8

The remaining steps are the same as in Example 3, the difference is that the NaOH aqueous solution ② is prepared with a concentration of 420g/L, which is an electrochemical anodic oxidation electrolyte, and the constant voltage of the DC power supply is 12V. After injection molding, the pull-out force was tested on a universal testing machine, and the test results are shown in Table 1 below.

Implementation Case 9

The remaining steps are the same as in Example 3, the difference is that the NaOH aqueous solution ② is prepared with a concentration of 480 g/L, which is an electrochemical anodic oxidation electrolyte, and the constant voltage of the DC power supply is 6V. After injection molding, the pull-out force was tested on a universal testing machine, and the test results are shown in Table 1 below.

Implementation Case 10

The remaining steps are the same as in Example 3, the difference is that the NaOH aqueous solution ② is prepared with a concentration of 500 g/L, which is an electrochemical anodic oxidation electrolyte, and the constant voltage of the DC power supply is 6V. After injection molding, the pull-out force was tested on a universal testing machine, and the test results are shown in Table 1 below.

Comparative case 1

1. Prepare an aqueous solution of sulfuric acid ①, the concentration is 100g/L, use a PP tank, dissolve and stir a large amount of heat and stand still for 2 hours, and then measure the temperature of 26 °C with a thermometer, and use it after it is completely dissolved.

2. Prepare an aqueous NaOH solution ② with a concentration of 200g/L, use a PP tank, dissolve and stir a large amount of heat and stand still for 2 hours, and then measure the temperature at 26°C with a thermometer, and use it after it is completely dissolved.

3. Grind the surface of the TC4 (3×12×40mm) metal substrate with a grinder, and then perform degreasing and water washing.

4. Put the TC4 metal matrix into the prepared sulfuric acid aqueous solution ①, the TC4 metal matrix is used as the cathode, the constant voltage of the DC power supply is 20V, and the water is washed after energizing for 10 minutes.

5. Put the TC4 metal matrix into the prepared NaOH aqueous solution ②, the TC4 metal matrix is used as the anode, the constant voltage of the DC power supply is 20V, and after energizing for 10 minutes, it is washed and dried.

6. Put the TC4 metal base into the injection molding machine to inject PBT plastic, and form a plastic part with the same size as the TC4 metal base at the end of the TC4 metal base. The schematic diagram is shown in Figure 4. After forming, the pull-out force was tested on a universal testing machine, and the test results are shown in Table 1 below.

Comparative case 2

1. Prepare an aqueous NaOH solution with a concentration of 280g/L, use a PP tank, dissolve and stir a large amount of heat and stand still for 2 hours, and then measure the temperature with a thermometer of 26°C, and use it after it is completely dissolved.

2. Grind the surface of the TC4 (3×12×40mm) metal substrate with a grinder, and then perform degreasing and water washing.

3. Put the TC4 metal matrix into the prepared NaOH aqueous solution, the TC4 metal matrix is used as the anode, the constant voltage of the DC power supply is 10V, and after energizing for 20 minutes, the water is washed and dried.

4. Put the TC4 metal base into the injection molding machine to inject PBT plastic, and form a plastic part with the same size as the TC4 metal base at the end of the TC4 metal base. The schematic diagram is shown in Figure 4. After forming, the pull-out force was tested on a universal testing machine, and the test results are shown in Table 1 below.

Comparative Case 3

1. Prepare a NaOH aqueous solution with a concentration of 450g/L, use a PP tank, dissolve and stir a large amount of heat and stand still for 2 hours, and then measure the temperature with a thermometer to 26°C, and use it after it is completely dissolved.

2. Grind the surface of the TC4 (3×12×40mm) metal substrate with a grinder, and then perform degreasing and water washing.

3. Put the TC4 metal matrix into the prepared NaOH aqueous solution, the TC4 metal matrix is used as the anode, the constant voltage of the DC power supply is 10V, and after energizing for 20 minutes, the water is washed and dried.

4. Put the TC4 metal base into the injection molding machine to inject PBT plastic, and form a plastic part with the same size as the TC4 metal base at the end of the TC4 metal base. The schematic diagram is shown in Figure 4. After forming, the pull-out force was tested on a universal testing machine, and the test results are shown in Table 1 below.

Comparative Case 4

1. Prepare an aqueous NaOH solution with a concentration of 280g/L, use a PP tank, dissolve and stir to generate a lot of heat, and place it in a 60°C constant temperature water bath for use.

2. Grind the surface of the TC4 (3×12×40mm) metal substrate with a grinder, and then perform degreasing and water washing.

3. Put the TC4 metal matrix into the prepared NaOH aqueous solution, soak it in a constant temperature water bath at 60°C for 120 minutes, wash it and bake it to dry.

4. Put the TC4 metal base into the injection molding machine to inject PBT plastic, and form a plastic part with the same size as the TC4 metal base at the end of the TC4 metal base. The schematic diagram is shown in Figure 4. After forming, the pull-out force was tested on a universal testing machine, and the test results are shown in Table 1 below.

Comparative case 5

The rest of the steps are the same as in Example 3, except that an aqueous solution of NaOH is prepared ① with a concentration of 100 g/L, which is used to soak the TC4 metal matrix. The test results are shown in Table 1 below.

Comparative case 6

The remaining steps are the same as those in Example 3, except that the NaOH aqueous solution ② is prepared with a concentration of 200 g/L, which is an electrochemical anodic oxidation electrolyte, and the constant voltage of the DC power supply is 10V. After injection molding, the pull-out force was tested on a universal testing machine, and the test results are shown in Table 1 below.

Comparative Case 7

The rest of the steps are the same as in Example 3, except that the NaOH aqueous solution is prepared (2), the concentration is 600g/L, which is an electrochemical anodic oxidation electrolyte, and the constant voltage of the DC power supply is 10V. After injection molding, the pull-out force was tested on a universal testing machine, and the test results are shown in Table 1 below.

Comparative Case 8

The remaining steps are the same as those in Example 3, except that the NaOH aqueous solution (2) is prepared, the concentration is 450g/L, which is an electrochemical anodic oxidation electrolyte, and the constant voltage of the DC power supply is 20V. After injection molding, the pull-out force was tested on a universal testing machine, and the test results are shown in Table 1 below.

The test equipment for the pull-out test is a universal testing machine, the pulling speed is 5 mm/min, and the unit is MPa (the force (N) acting on the unit area (m ² )).

Table 1

It can be seen from the test results in Table 1 that all the examples of the present application have a pull-out strength of 34 MPa or more.

Table 2 Environmental test results

It can be seen from the test results in Table 2 that after the reliability test, the pull-out strength does not decrease significantly.

In the description of the present invention, the orientation or positional relationship indicated by the terms "upper", "lower", etc. is based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and does not require the present invention to be in a specific manner. The orientation configuration and operation are therefore not to be construed as limiting the invention.

In the description of this specification, description with reference to the terms "one embodiment", "another embodiment", etc. means that a particular feature, structure, material or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention . In this specification, schematic representations of the above terms are not necessarily directed 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, those skilled in the art may combine and combine the different embodiments or examples described in this specification, as well as the features of the different embodiments or examples, without conflicting each other. In addition, it should be noted that in this specification, the terms "first" and "second" are only used for description purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features.

Although the embodiments of the present invention have been shown and described above, it should be understood that the above-mentioned embodiments are exemplary and should not be construed as limiting the present invention. Embodiments are subject to variations, modifications, substitutions and variations.

Claims (9)

1. a method for preparing resin-metal composite is characterized in that, comprising: providing a metal matrix, and soaking the metal matrix in an inorganic alkaline solution; performing anodization treatment on the metal substrate 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 substrate; and injecting resin at the position of the porous oxide film on the metal substrate to form the resin-metal composite, Wherein, the metal matrix includes titanium and titanium alloy, the thickness of the porous oxide film is 100-500nm, The inorganic alkaline solution includes at least one of hydroxides of alkali metals and strong bases and weak acid salts, and the concentration of solutes in the inorganic alkaline solution is 250g-400g/L; The alkaline electrolyte includes an inorganic base, and the concentration of the electrolyte in the alkaline electrolyte is 400-500 g/L. 2 . The method according to claim 1 , wherein the porous oxide film comprises large pores with a pore size of 100-30000 nm and small pores with a pore size of 20-300 nm. 3 . 3 . The method according to claim 1 , wherein the temperature of the inorganic alkaline solution during the soaking treatment is 50-70 degrees Celsius, and the soaking time is 20-120 minutes. 4 . 4. The method according to claim 1 or 2, wherein the temperature of the alkaline electrolyte is 10-40 degrees Celsius during the anodizing treatment, and the time is 5-30 minutes. 5. The method according to claim 1 or 2, wherein the voltage of the anode in the anodizing process is controlled to be 5-15V. 6. The method according to claim 1 or 2, wherein the current density of the anode in the anodizing process is controlled to be 0.2-0.8 A/dm ² . 7. The method according to claim 1 or 2, further comprising at least one of the following steps: Before soaking the metal substrate in the inorganic alkaline solution, the metal substrate is subjected to grinding treatment, degreasing treatment and first cleaning treatment in advance; After the soaking treatment is performed on the metal substrate and before the anodizing treatment, a second cleaning treatment is performed on the metal substrate subjected to the soaking treatment; After the anodizing treatment is performed on the metal substrate, and before resin injection is performed, the metal substrate is subjected to a third cleaning treatment and a drying treatment. 8. A resin-metal composite, characterized in that, comprising: a metal substrate, at least part of the surface of the metal substrate has a porous oxide film, the porous oxide film includes large pores with a pore size of 100-30000 nm, and small pores with a pore size of 20-300 nm; and an injection part, the injection part is formed of resin, the injection part is located on the metal base where the porous oxide film is formed, Wherein, the resin-metal composite is prepared by the method of any one of claims 1-7. 9. A housing comprising the resin-metal composite of claim 8.

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