WO2018171077A1

WO2018171077A1 - Stainless steel and plastic combined piece and processing method therefor

Info

Publication number: WO2018171077A1
Application number: PCT/CN2017/090915
Authority: WO
Inventors: 张法亮; 董晓佳; 王成; 张孟军; 刘鸿章; 唐红平; 刘利强
Original assignee: 歌尔股份有限公司
Priority date: 2017-03-20
Filing date: 2017-06-29
Publication date: 2018-09-27
Also published as: CN106965374A

Abstract

A stainless steel and plastic combined piece and a processing method therefor. The combined piece comprises a stainless substrate (1). When etched by an etchant, the surface of the stainless steel substrate (1) is provided with several recessed structures (11). The average depth of the recessed structures (11) is 0.1-30 micrometers and the average width is 0.2-15 micrometers. A plastic (2) is injection molded on the stainless steel substrate (1). Parts of the structure of the plastic (2) are embedded in the recessed structures (11). The recessed structures (11) formed when the stainless steel substrate (1) is etched by the etchant are of the micrometer level, the combined piece is provided with improved stability and increased airtightness when the plastic (2) is injection molded, thus reducing process steps, reducing production costs, being applicable in large-scale production, placing no special material requirement with respect to the injection molded plastic (2), and having a widened range of applications.

Description

Combined piece of stainless steel and plastic and processing method thereof

Technical field

The invention relates to the field of product compounding technology, and more particularly to a joint of stainless steel and plastic and a processing method thereof.

Background technique

With the rapid development of the electronics industry, more and more electronic products are made of a composite product formed by combining metal and plastic to achieve the purpose of appearance metal and internal plastic.

At present, in the method of metal-plastic injection molding, generally, nano-scale pores are formed by processing in a plurality of processing steps on the surface of the metal substrate, and the nano-sized pores are generally perpendicular to the metal substrate. Specifically, the micro-scale macropores can be formed on the surface of the metal substrate, and further etched to form nano-sized pores. In order to achieve a better filling effect, it is often necessary to coat a pore wall with a layer of a pore-orating agent or an oxide film. Finally, the plastic is pressed directly into the surface of the metal substrate having several nanometer-sized pores. However, this method can only be applied on a large scale on aluminum alloys and cannot be applied to other metals or alloys such as stainless steel. This is because nano-sized pores are not readily available in most other metals or alloys, or the size and distribution of the pores obtained by this method do not have the effect of making the metal firmly bonded to the plastic.

Therefore, if the nano-injection method is combined with plastic on stainless steel, the composite product formed after the combination has many problems such as unstable process and poor reliability. Therefore, it is necessary to improve the existing stainless steel and plastic composite products and their processing methods.

Summary of the invention

It is an object of the present invention to provide a new technical solution for a combination of stainless steel and plastic and a method of processing the same.

According to a first aspect of the invention, a combination of stainless steel and plastic is provided. The bonding member comprises a stainless steel substrate, and a plurality of surfaces are formed on the surface of the stainless steel substrate after etching by an etching solution a recessed structure having an average depth of 0.1-30 micrometers, an average width of the recessed structure of 0.2-15 micrometers, a plastic formed on the stainless steel substrate by injection molding, and a part of the structure of the plastic embedded in the Within the recessed structure.

Optionally, the recessed structure has an average length greater than 0.2 microns.

Optionally, the recess structure comprises at least one of a strip structure, a fold structure, and a curved structure.

Optionally, the projection of the recessed structure on the surface of the stainless steel substrate comprises a closed pattern.

Optionally, the cross-sectional shape of the recessed structure in a direction perpendicular to the surface of the stainless steel substrate comprises at least one of an inverted triangle, an arc, a U, and a quad.

Optionally, the etching solution comprises at least one of nitric acid, phosphoric acid, sulfuric acid, sulfurous acid, hydrochloric acid, oxalic acid, acetic acid, hydrofluoric acid, maleic acid, phthalic acid, oxalic acid solution and a salt solution thereof. .

Optionally, the etching solution comprises: a combination of 5-30% oxalic acid solution and a chloride or sulfate, a combination of 1-60% nitric acid and chloride or oxide, 10-30% nitric acid and 5-15% At least one of a combination of a metal nitrate and a 2-10% sulfate.

Optionally, the etching solution is etched at a temperature of 20-90 degrees Celsius for a period of 1-50 minutes.

Optionally, an oxide film layer is formed on a surface of the recess structure, and the oxide film layer has a thickness of 1-20 nm.

Optionally, the oxide film layer includes at least two of iron oxide, chromium oxide, and nickel oxide.

Optionally, the plastic comprises a thermoplastic resin and a filler material, the filler material is 5-40% by mass in the plastic, and the filler material comprises nylon fiber, carbon fiber, glass fiber, and aramid fiber. At least one of calcium carbonate, magnesium carbonate, silica, and clay.

Optionally, the thermoplastic resin comprises at least one of a polyphenylene sulfide resin, a polybutylene terephthalate resin, a polyamide, a polycarbonate, and a polyolefin.

According to a second aspect of the invention, there is also provided a method of processing a joint of stainless steel and plastic. The processing method includes: providing a stainless steel substrate; performing corrosion etching on the stainless steel substrate Engraving, forming a plurality of recessed structures having a depth of 0.1-30 micrometers and a width of 0.2-15 micrometers on the surface of the stainless steel substrate; molding plastic onto the surface of the stainless steel substrate to make a part of the structure in the plastic Embedded into the recessed structure to form a joint of stainless steel and plastic.

Optionally, the temperature during the etching of the etching solution is 20-90 degrees Celsius and the time is 1-50 minutes.

Alternatively, after the recessed structure is formed on the surface of the stainless steel substrate, an oxide film layer is further formed on the surface of the stainless steel substrate, and the oxide film layer has a thickness of 1 to 20 nm.

The inventors of the present invention have found that in the prior art, although there are technical solutions for injection-molding some metal materials with plastic materials, the composite products formed by nano-scale small-hole injection molding have unstable process and poor reliability. And so many questions. There is no improved technical solution with high reliability in the prior art.

The recessed structure formed by the etching process of the stainless steel substrate in the invention is micron-sized, and the stability of the joint after the injection molding of the plastic is better and the airtightness is better. The process flow is shortened, the production cost is reduced, and it is more suitable for mass production. There is no special material requirement for injection molding plastics, and the scope of application is wider.

Therefore, the technical task to be achieved by the present invention or the technical problem to be solved is the field. The invention has never been or is not expected, so the invention is a new technical solution.

Other features and advantages of the present invention will become apparent from the Detailed Description of the <RTIgt;

DRAWINGS

The accompanying drawings, which are incorporated in FIG

1 is a schematic structural view of a stainless steel and a plastic joint according to an embodiment of the present invention;

2 is a schematic view showing a recessed structure on a stainless steel substrate according to an embodiment of the present invention;

3 is a schematic view showing a recessed structure on a stainless steel substrate according to an embodiment of the present invention;

4 is a schematic cross-sectional view of a joint after shear fracture according to an embodiment of the present invention.

detailed description

Various exemplary embodiments of the present invention will now be described in detail with reference to the drawings. It should be noted that the relative arrangement of the components and steps, numerical expressions and numerical values set forth in the embodiments are not intended to limit the scope of the invention unless otherwise specified.

The following description of the at least one exemplary embodiment is merely illustrative and is in no way

Techniques, methods and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail, but the techniques, methods and apparatus should be considered as part of the specification, where appropriate.

In all of the examples shown and discussed herein, any specific values are to be construed as illustrative only and not as a limitation. Thus, other examples of the exemplary embodiments may have different values.

It should be noted that similar reference numerals and letters indicate similar items in the following figures, and therefore, once an item is defined in one figure, it is not required to be further discussed in the subsequent figures.

The present invention provides a joint of stainless steel and plastic that includes a stainless steel substrate and plastic. As shown in FIG. 1 to FIG. 4, after etching by the etching solution, the surface of the stainless steel substrate 1 is A plurality of recessed structures 11 are formed on the surface, and the recessed structures 11 are micron-scale etch marks. The recessed structure 11 has an average depth H of 0.1 to 30 μm, and the recessed structure 11 has an average width W of 0.2 to 15 μm. There is a different inclination angle between the obtained recessed structure 11 and the surface of the stainless steel substrate 1. Specifically, the recess structure 11 includes a first recess structure having a slope with respect to a surface of the stainless steel substrate 1. The slope of the first recessed structure with respect to the surface of the stainless steel substrate 1 may have different values. The recessed structure 11 may further include a second recessed structure perpendicular to the surface of the stainless steel substrate 1. As such, the recessed structure 11 including the first recessed junction and the second recessed structure has different inclination angles with respect to the surface of the stainless steel substrate 1.

The recessed structure 11 formed by the etching of the etching solution has a great relationship with the chromium-depleted region in the structure of the stainless steel substrate 1. Specifically, in the stainless steel substrate 1, carbon (C) and chromium (Cr) are easily formed into carbides due to the instability of the structure and the change in saturation of carbon in different forms, mainly (Cr, Fe). ₂₃ C ₆ type, and precipitated at crystal defects such as grain boundaries, resulting in the formation of a large number of (Cr,Fe) ₂₃ C ₆ type crystals in the crystal defects in the stainless steel matrix, and the solid solution chromium atoms are greatly reduced to form a certain shape. In the chromium-depleted region, a region of corrosion-resistant and corrosion-resistant cross-distribution is formed on the stainless steel substrate 1. Such chromium-depleted regions are also solute atoms, impurities, and second equal enrichment regions, forming a living-passive micro-galvanic structure, which is corroded and corroded by a specific corrosive medium. The recessed structure 11 is described.

The stainless steel substrate 1 is injection molded with a plastic 2, and a part of the structure of the plastic 2 is embedded in the recessed structure 11 to form the joint. Since the recessed structure 11 has different inclination angles with respect to the surface of the stainless steel substrate 1, a part of the structure in the plastic 2 can be embedded into the inside of the recessed structure 11 at different inclination angles. Alternatively, the recessed structure 11 may be formed only on the stainless steel substrate 1 where the plastic 2 needs to be injection molded. Alternatively, the recessed structure 11 may be formed on the entire surface of the stainless steel substrate 1.

The joint of stainless steel and plastic provided by the invention has the following technical effects. First, the technical solution is to form the recessed structure 11 in a corrosive area, which is a micron-scale structure. Due to the different inclination angles between the recessed structure 11 and the surface of the stainless steel substrate 1, when the plastic 2 is injection molded onto the surface of the stainless steel substrate 1, the partial structure in the plastic 2 can be inclined differently. An angle is embedded into the recessed structure 11 to form a joint of plastic and stainless steel. And the continuity of the recessed structure 11 is good, and thus the connection of the plastic 2 filled into the recessed structure 11 is completed. The consistency is also good. Therefore, the plastic 2 can be embedded in the recessed structure 11 on the surface of the stainless steel substrate 1 like the root of the plant, and the bonding force is large, and the plastic 2 is not easily peeled off during stretching or shearing.

Fig. 4 is a schematic cross-sectional view showing the joint surface of the stainless steel substrate 1 and the plastic 2 after the tensile test in the present embodiment. In this example, the micro-scale recessed structure 11 formed by etching is larger and deeper, and the plastic 2 can be better filled in the recessed structure 11 without the activation of the porogen. After the tensile tensile test, the joint fractured portion is in the middle of the plastic 2, and the joint surface of the plastic 2 and the stainless steel substrate 1 is not cracked, thereby demonstrating the between the stainless steel substrate 1 and the plastic 2 in the present invention. Has a strong binding force.

Second, the stainless steel substrate 1 has regions of different structures, such as a chromium-depleted region, such as high-potential substances such as solid solution atoms, second phase, and impurities, or crystal defects such as grain boundaries and twins. It is a high-energy, lively area. Impregnated in the corrosive solution of this scheme, the above areas preferentially corrode and fall off, while other areas only cause slight corrosion, which greatly reduces the consumption of corrosive liquid. For example, for austenitic stainless steel, the recessed structure 11 can be formed by one dipping. For other stainless steels, the recessed structure 11 can be formed by adding a further corrosion extension on the basis of the first etching. After that, direct injection molding eliminates the need for additional processing. Therefore, the technical solution of the present invention is simplified in the hole forming process, and the scrap rate of the joint member is reduced.

Third, the injection molded plastic of the present invention is suitable for most plastics, including thermoplastic resins such as polyphenylene sulfide resin (PPS), polybutylene terephthalate resin (PBT), polyamide (PA), polycarbonate. (PC), polyolefin, polystyrene. However, the small blind holes formed in the prior art have poor fluidity in the blind holes, and physical and chemical reactions with the PA or PBT materials are required by means of the pore-treating agent. Therefore, the conventional technical solutions are mostly limited to PA. Or PBT materials, only these two types of plastics contain a large amount of carboxyl groups, and an exothermic reaction with the cations in the pore former. Plastics in injection molding require heat generated by an exothermic reaction to retard solidification in the pores. However, the size of the micron-sized recessed structure 11 in the present invention is large, and a good filling can be obtained without the exothermic reaction of the plastic and the pore-piercing agent, thereby expanding the selection range of the plastic.

In order to obtain a good bonding force after embedding a partial structure in the plastic 2 into the micro-scale recessed structure 11, preferably, as shown in FIG. 3, the recessed structure 11 has an average length L of more than 0.2 μm. Specifically, the size of the desired recessed structure 11 can be obtained by controlling the composition of the corrosive medium, the etching time, the etching temperature, and the like during the etching.

Preferably, the cross section of the recessed structure 11 in a direction perpendicular to the surface of the stainless steel substrate 1 includes at least one of an inverted triangle, an arcuate shape, a U shape, and a quadrangular shape. Thus, the plastic 2 is easily inserted into the recessed structure 11 during injection molding.

The extending direction and the distribution form of the recessed structure 11 may be different in that the recessed structure 11 obtained by etching can generate an adsorption force to the plastic 2 embedded in the injection molding. Preferably, the recess structure 11 may include at least one of a strip structure, a fold structure, and a curved structure. In the recessed structure in any of the structures, the inner recessed space formed by the recessed structure should ensure good coherence and no abrupt change in the direction of extension. In this way, it is more convenient to embed the plastic 2 into the recessed structure 11.

The intergranular corrosion on the stainless steel substrate 1 is performed along the edges of the crystal grains, and thus the projection of the recessed structure 11 on the surface of the stainless steel substrate 1 may include a closed pattern. For example, the closed pattern may be a closed figure of a rectangle, a ring or other irregular shape surrounding the die. For example, Figure 2 and Figure 3. It should be noted that the closed pattern may be formed by at least one of a plurality of strip structures, a fold structure, and a curved structure. The projection of the recessed structure 11 on the surface of the stainless steel substrate 1 may also include an open pattern. As shown in FIG. 3, the recessed structure 11 may be a strip structure or the like having an average length L of more than 0.2 mm.

Preferably, the surface of the recessed structure 11 is formed with an oxide film layer having a thickness of 1 to 20 nm. Further, the oxide film layer includes at least two of iron oxide, chromium oxide, and nickel oxide. Compared with the stainless steel substrate 1, the thermal conductivity of the oxide film is low, and the heat loss of the plastic 2 can be reduced during injection molding, and the time for solidification and crystallization of the plastic 2 is delayed, so that the plastic 2 can be more fully filled in the recessed structure 11 The bottom of the recessed structure 11 can also achieve better filling. For example, in the case of 400 ° C, the thermal conductivity of stainless steel is 16.3 W / m · K, the thermal conductivity of ferric oxide is 5.1 W / m · K, the thermal conductivity of ferrous oxide is 15.0 W / m · K, oxidation The thermal conductivity of chromium is about 10 W/m·K.

It should be noted that the formation mode of the oxide film layer is not limited, and may include high temperature oxidation, chemical passivation, and electrochemical passivation. In either case, the final effect is to form a dense, thermally insulating oxide film on the stainless steel surface.

The linear expansion coefficient of the plastic 2 should be as close as possible to the stainless steel substrate 1 to facilitate the curing of the injection molding. Since the linear expansion coefficient of PPS or PBT materials commonly used for injection molding is about 6-8×10 ^-5 /°C, and the linear expansion coefficient of stainless steel is 1.5×10 ^-5 /°C, the difference is large. Therefore, it is necessary to modify the main component resin material to significantly lower the linear expansion coefficient of the composition. Preferably, the plastic 2 comprises a thermoplastic resin and a filling material. For example, the thermoplastic resin may include at least one of a polyolefin polyphenylene sulfide resin, a polybutylene terephthalate resin, a polyamide, a polycarbonate, and a polyolefin. The filling material may be 5-40% by mass in the plastic 2, and the filling material may include nylon fiber, carbon fiber, glass fiber, aramid fiber, calcium carbonate, magnesium carbonate, silicon dioxide and At least one of the clays. Thus, the filler material improves the main component resin material of the plastic 2, and can significantly reduce the linear expansion coefficient of the plastic 2, thereby approaching the linear expansion coefficient of the stainless steel.

In the present invention, a method of processing stainless steel and plastic joints includes:

First, a stainless steel substrate 1 is provided to facilitate injection molding of the plastic 2 onto the surface of the stainless steel substrate 1. At present, commonly used stainless steels include austenitic stainless steel and martensitic stainless steel, and the chromium content in the structure is greater than 12%. The chromium atom has a small diffusion rate in stainless steel and is easy to form a chromium-depleted region. The main reason for the strong corrosion resistance of stainless steel is that the chromium element is oxidized to form a dense oxide film, which improves the corrosion resistance of the material. Therefore, a large number of corrosive areas such as chromium-depleted areas provide a good basis for the subsequent etching of stainless steel. Thus, the present technical solution is not applicable to steel materials, but is applicable to all stainless steels.

In order to facilitate the corrosion treatment of the surface of the stainless steel substrate 1, the stainless steel substrate 1 may be first subjected to degreasing and degreasing treatment. Specifically, the stainless steel substrate 1 may be immersed in a cleaning agent of 35-80 degrees Celsius for sonication for 60-600 seconds. After that, rinse with pure water. For example, the cleaning agent may be an acid, a base or an organic solvent of 100 to 300 g/L or the like.

Thereafter, the stainless steel substrate 1 is subjected to an etching solution etching treatment to form a micron-sized recessed structure 11. 2, 3, and 4 show surface topography features etched by the present technical solution. The recessed structure 11 has an average depth H of 0.1-30 microns and an average width W of 0.2-15 microns.

The recessed structure 11 includes a first recessed structure having a slope with respect to the stainless steel substrate 1. The slope of the first recessed structure with respect to the surface of the stainless steel substrate 1 may have different values. The recessed structure 11 may further include a second recessed structure perpendicular to the surface of the stainless steel substrate 1. As such, the recessed structure 11 including the first recessed junction and the second recessed structure The surface of the stainless steel substrate 1 has different inclination angles. It is possible to embed a part of the structure in the plastic like the root of the plant in the recessed structure 11 with a greater bonding force therebetween.

The key to the corrosion of stainless steel to form the recessed structure 11 is the inconsistency of the corrosion rate between the chromium-depleted area and other areas, that is, the corrosion rate of the chromium-depleted area is greater than that of other areas. Therefore, the type and composition of the etching liquid not only determine whether or not the recessed structure 11 can be formed, but also determines the size of the recessed structure 11. Therefore, several sets of etching liquids are preferred in the present scheme to constitute a weak oxidizing medium, which is more advantageous for the formation of the micro-scale recessed structure 11. Optionally, the etching solution comprises at least one of nitric acid, phosphoric acid, sulfuric acid, sulfurous acid, hydrochloric acid, oxalic acid, acetic acid, hydrofluoric acid, maleic acid, phthalic acid, oxalic acid solution and a salt solution thereof. . Optionally, the etching solution comprises: a combination of 5-30% oxalic acid solution and a chloride or sulfate, a combination of 1-60% nitric acid and chloride or oxide, 10-30% nitric acid and 5-15% At least one of a combination of a metal nitrate and a 2-10% sulfate.

Preferably, the temperature during the etching solution etching process is controlled at 20-90 degrees Celsius for a duration of 1-50 minutes. Thus, by controlling a plurality of parameters in the method, the required size and shape of the recessed structure 11 can be obtained.

Alternatively, after the recess structure 11 is formed on the surface of the stainless steel substrate 1, the surface of the recess structure 11 may be processed to form an oxide film layer. The oxide film layer may have a thickness of 1 to 20 nm. The oxide film layer may include at least two of iron oxide, chromium oxide, and nickel oxide. In this way, the heat loss of the plastic 2 can be reduced during the injection molding, and the time for the plastic 2 to solidify and crystallize is delayed, so that the plastic 2 can be more fully filled in the recessed structure 11, and the bottom of the recessed structure 11 can also be better. The padding. It should be noted that the formation mode of the oxide film layer is not limited, and may include high temperature oxidation, chemical passivation, and electrochemical passivation. In either case, the final effect is to form a dense, thermally insulating oxide film on the stainless steel surface.

Finally, plastic 2 is injection molded onto the surface of the stainless steel substrate 1, and a part of the structure in the plastic 2 is embedded in the recessed structure 11 to form a joint of stainless steel and plastic. Preferably, the plastic 2 comprises a thermoplastic resin and a filling material. The thermoplastic resin may include at least one of a polyolefin polyphenylene sulfide resin, a polybutylene terephthalate resin, a polyamide, a polycarbonate, and a polyolefin. The filling material may be 5-40% by mass in the plastic 2, and the filling material may include nylon fiber, carbon fiber, glass fiber, aramid fiber, calcium carbonate, magnesium carbonate, silicon dioxide and At least one of the clays. As such, the filler material pair The main component resin material of the plastic 2 is modified to significantly reduce the linear expansion coefficient of the plastic 2, thereby approaching the linear expansion coefficient of the stainless steel.

In a specific embodiment of the present invention, the stainless steel substrate 1 is etched by a combined etching solution of 10-30% nitric acid and 5-15% metal nitrate and 2-10% sulfate, and the etching temperature is 60 degrees Celsius. Then, a plastic material mixed with PBT + 30 wt% glass fibers was injected onto the surface of the stainless steel substrate 1 at an injection temperature of 300 ° C to finally obtain a joint of stainless steel and plastic. The area of the plastic and stainless steel joint was 0.5 cm ² and was drawn and stretched on a tensile tester to obtain an average shear breaking force of 32.5 MPa.

While the invention has been described in detail with reference to the preferred embodiments of the present invention, it is understood that It will be appreciated by those skilled in the art that the above embodiments may be modified without departing from the scope and spirit of the invention. The scope of the invention is defined by the appended claims.

Claims

A joint of stainless steel and plastic, characterized in that the joint comprises a stainless steel substrate, and after etching by an etching solution, a plurality of concave structures are formed on the surface of the stainless steel substrate, and the average depth of the recessed structure is 0.1 -30 microns, the recessed structure has an average width of 0.2-15 microns, and the stainless steel substrate is injection molded with plastic, and a part of the structure of the plastic is embedded in the recessed structure.
The combination of stainless steel and plastic of claim 1 wherein said recessed structure has an average length greater than 0.2 microns.
The combination of stainless steel and plastic according to claim 1, wherein the recessed structure comprises at least one of a strip structure, a fold structure, and a curved structure.
The combination of stainless steel and plastic of claim 1 wherein the projection of the recessed structure on the surface of the stainless steel substrate comprises a closed pattern.
The joint of stainless steel and plastic according to claim 1, wherein a cross-sectional shape of the recessed structure in a direction perpendicular to a surface of the stainless steel base material comprises at least at least one of an inverted triangle, an arcuate shape, a U-shaped shape, and a quadrangular shape. One.
The joint of stainless steel and plastic according to claim 1, wherein an oxide film layer is formed on a surface of the recessed structure, and the oxide film layer has a thickness of 1 to 20 nm.
The combination of stainless steel and plastic according to claim 6, wherein the oxide film layer comprises at least two of iron oxide, chromium oxide and nickel oxide.
The combination of stainless steel and plastic according to claim 1, wherein the plastic comprises a thermoplastic resin and a filler, the filler material being 5-40% by mass in the plastic, the filler material It includes at least one of nylon fiber, carbon fiber, glass fiber, aramid fiber, calcium carbonate, magnesium carbonate, silica, and clay.
The combination of stainless steel and plastic according to claim 8, wherein said thermoplastic resin comprises at least at least polyphenylene sulfide resin, polybutylene terephthalate resin, polyamide, polycarbonate, and polyolefin. One.
A method for processing a joint of stainless steel and plastic, comprising: providing a stainless steel substrate; performing an etching solution etching treatment on the stainless steel substrate, wherein the stainless steel substrate The surface forms a plurality of recessed structures having an average depth of 0.1-30 microns and an average width of 0.2-15 microns; plastic is injected onto the surface of the stainless steel substrate such that a portion of the structure in the plastic is embedded into the recessed structure To form a joint of stainless steel and plastic.
The method for processing a stainless steel and a plastic joint according to claim 10, wherein the etching solution comprises: nitric acid, phosphoric acid, sulfuric acid, sulfurous acid, hydrochloric acid, oxalic acid, acetic acid, hydrofluoric acid, maleic acid, benzene. At least one of a diacid, an oxalic acid solution, and a salt solution thereof.
The method for processing a stainless steel and plastic joint according to claim 10, wherein the etching solution comprises: a combination of 5-30% oxalic acid solution and a chloride or sulfate, 1-60% nitric acid and chloride Or a combination of oxides, at least one of 10-30% nitric acid and a combination of 5-15% metal nitrate and 2-10% sulfate.
The method of processing a stainless steel and plastic joint according to claim 10, wherein the etching temperature of the etching solution is 20-90 degrees Celsius and the time is 1-50 minutes.
The method for processing a stainless steel and a plastic joint according to claim 10, wherein after the recessed structure is formed on the surface of the stainless steel substrate, an oxide film layer is further formed on the surface of the stainless steel substrate. The oxide film layer has a thickness of 1 to 20 nm.
The method of processing a stainless steel and plastic joint according to claim 14, wherein the oxide film layer comprises at least two of iron oxide, chromium oxide and nickel oxide.