KR102395519B1 - Plating method of metal surface - Google Patents

Abstract

The present invention relates to a method of plating a metal surface and, more specifically, to a method of plating a metal surface, capable of being applied to various fields due to an oxidized film having excellent adhesiveness, durability, corrosion-resistance and wear-resistance, and maintaining the safety of workers and preventing environmental pollution by effectively adsorbing and removing pollutants produced during a process. In order to achieve the purpose, the method of plating a metal surface includes the following steps of: immersing a material to be plated in a degreasing solution including sodium hydroxide and nitric acid to degrease the material; chemically etching the degreased material to be plated; corroding the surface of the chemically etched material to be plated to apply a matt finish thereto; immersing the matt-finished material to be plated in an electrolyte to form an oxidized film on the surface of the material to be plated; washing the material to be plated with the oxidized film to remove foreign substances therefrom; immersing the material to be plated, from which the foreign substances have been removed, in a dye composition to color the material; and sealing the colored material to be plated to perform a surface treatment thereon.

Description

Plating method of metal surface {PLATING METHOD OF METAL SURFACE}

The present invention relates to a method for plating a metal surface, and more particularly, it can be utilized in various fields due to excellent adhesion, durability, corrosion resistance, and abrasion resistance of the oxide film, and effectively adsorbs contaminants generated during the process; It relates to a method for plating a metal surface that can protect workers' safety and prevent environmental pollution by removing it.

Many products in the commercial and consumer industries are metal articles or contain metal parts.

The metal surfaces of these products are surface-treated to improve general properties such as corrosion resistance, abrasion resistance and hardness. In particular, when metals such as aluminum (Al) are surface-treated through anodizing, extremely small pores are formed along with corrosion resistance and abrasion resistance, so that various colors can be colored, resulting in beautiful appearance can be obtained

Anodization is one of the surface treatment methods of metal. When a metal base material is used as an anode and electricity is energized in the presence of an electrolyte, the surface of the metal base material is oxidized by oxygen generated from the anode to form an oxide film (eg, Al ₂ O ₃ ). is formed

In more detail, oxygen ions and hydroxide ions of the electrolyte for anodization advance to the metal surface, penetrate the existing oxide film, combine with metal ions, and form a porous oxide film and hydroxide film near the interface between the metal and the oxide layer. .

The porous oxide film grows directly on the active layer by the dissolution action of the acidic electrolyte. At this time, the formed oxide film is very hard and imparts weather resistance to the metal, and the porosity exhibits various functions by adsorbing/bonding with dyes, pigments, corrosion inhibitors or lubricants, etc.

As described above, the anodized metal surface has excellent hardness and corrosion resistance, and excellent aesthetics, so it is widely used as a exterior material. In this anodization process, the higher the purity of the metal to be plated, the more beautiful and glossy the film can be obtained. In addition, when anodized, a film with low porosity can be obtained, so it can be used as an electric capacitor, and since it has excellent corrosion resistance and insulation, it is widely used in various chassis, camera parts, aircraft, precision machinery and measuring instruments, etc. is becoming

In addition, anodized metal surfaces and plated metal surfaces can also be used to achieve a desired decorative effect. For example, the porosity of a metal oxide layer created by anodization can be used to absorb dyes to impart color to the anodized metal surface.

A plated metal surface can be made to have different finishes, and thus the finished surface can have an appearance ranging from a matte appearance to a glossy appearance and a brightly shiny appearance. There is a continuing need for metal surface treatment to produce durable and aesthetically pleasing products.

In general, the surface treatment process of a metal through anodization may be largely divided into a pretreatment process, an anodization process, and a post-treatment process. In this case, the pretreatment process generally includes degreasing, etching, and desmut processes. In the anodization process, an oxide film is grown. In addition, the post-treatment process includes a coloring process of applying a color to the oxide film, a sealing process of sealing pores formed in the oxide film, and a water washing process of washing with water.

However, although the metal plated through the general anodization method has improved weather resistance than before anodization, it is not very satisfactory. For example, it does not have sufficient high weather resistance to be applied as a frame of a solar cell module exposed to the outside for a long time.

In addition, the anodizing surface treatment according to the prior art has a problem of generating a large amount of various environmental control substances such as phosphorus compounds and acidic components during the treatment process.

Republic of Korea Patent Publication No. 10-2021-0140976

An object of the present invention is to solve the above problems, and to provide a method for plating a metal surface that can effectively adsorb and remove contaminants generated during the process while having high durability.

These and other objects and advantages of the present invention will become apparent from the following description of preferred embodiments.

The above object is to degrease the object to be plated by immersing it in a degreasing solution containing sodium hydroxide and nitric acid; chemically etching the degreased object to be plated; corroding the surface of the chemically etched object to be plated; immersing the matt-treated object to be plated in an electrolyte solution to form an oxide film on the surface of the object to be plated; removing foreign substances by washing the object to be plated on which the oxide film is formed; immersing the object to be plated from which the foreign matter has been removed in a dye composition to color it; and sealing the colored object to be plated and surface-treating it; including, wherein, during the step of forming an oxide film on the surface of the object to be plated and the step of coloring the object to be plated, an adsorbent is repeatedly sprayed to contaminants It can be achieved by the plating method of the metal surface, characterized in that it comprises the step of removing the.

Specifically, the electrolyte may include at least one selected from the group consisting of sulfuric acid, nitric acid, phosphoric acid, oxalic acid, chromic acid, oxalic acid, and combinations thereof.

Specifically, the object to be plated may include at least one selected from the group consisting of aluminum, manganese, magnesium, zinc, copper, zirconium, titanium, and combinations thereof.

According to the present invention, by forming an oxide film on the surface of the object to be plated through anodizing, the surface of the metal can be effectively plated while improving corrosion resistance and electrical conductivity, and the adhesion, durability, corrosion resistance, and Because of its excellent wear resistance, it has the effect that it can be used in various fields such as chassis, camera parts, aircraft, precision machinery and measuring instruments.

In addition, according to the present invention, it is possible to improve the adhesion between the object to be plated and the oxide film, and by effectively adsorbing and removing contaminants generated during the process, it is possible to protect the safety of workers and solve the pollution problem to a large extent.

However, the effects of the present invention are not limited to the above-mentioned effects, and other effects not mentioned will be clearly understood by those skilled in the art from the following description.

1 (a) to (d) are images showing a method for plating a metal surface according to an embodiment of the present invention.
2 (a) to (d) are images showing a method for plating a metal surface according to an embodiment of the present invention.
3 (a) to (c) are images showing a method for plating a metal surface according to an embodiment of the present invention.
4 (a) to (d) are images showing a metal surface plated according to an embodiment of the present invention.

Hereinafter, the present invention will be described in detail with reference to embodiments and drawings of the present invention. It will be apparent to those of ordinary skill in the art that these examples are merely presented by way of example to explain the present invention in more detail, and that the scope of the present invention is not limited by these examples. .

Further, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, and in case of conflict, this specification, including definitions will take precedence.

In order to clearly explain the invention proposed in the drawings, parts irrelevant to the description are omitted, and similar reference numerals are assigned to similar parts throughout the specification. And, when a part "includes" a certain component, this means that other components may be further included, rather than excluding other components, unless otherwise stated. In addition, "unit" described in the specification means one unit or block that performs a specific function.

In each step, identification numbers (first, second, etc.) are used for convenience of description, and identification numbers do not describe the order of each step, and each step does not clearly describe a specific order in context. It may be performed differently from the order specified above. That is, each step may be performed in the same order as the specified order, may be performed substantially simultaneously, or may be performed in the reverse order.

Hereinafter, embodiments and examples of the present application will be described in detail with reference to the accompanying drawings. However, it may not be limited to these embodiments and examples and drawings of the present application.

One aspect of the present application includes the steps of degreasing the object to be plated by immersing it in a degreasing solution containing sodium hydroxide and nitric acid; chemically etching the degreased object to be plated; corroding the surface of the chemically etched object to be plated; immersing the matt-treated object to be plated in an electrolyte solution to form an oxide film on the surface of the object to be plated; removing foreign substances by washing the object to be plated on which the oxide film is formed; immersing the object to be plated from which the foreign matter has been removed in a dye composition to color it; and sealing the colored object to be plated and surface-treating it; including, wherein, during the step of forming an oxide film on the surface of the object to be plated and the step of coloring the object to be plated, an adsorbent is repeatedly sprayed to contaminants It provides a method for plating a metal surface, characterized in that it comprises the step of removing the.

According to the present invention, it can be plated effectively while improving the corrosion resistance and electrical conductivity of the object to be plated, and the formed oxide film has excellent adhesion, durability, corrosion resistance, and abrasion resistance to chassis, camera parts, aircraft, precision machinery and measurement It has the effect that it can be used in various fields such as devices. In addition, by effectively adsorbing and removing pollutants generated during the process, there is an advantage in that the safety of workers can be maintained and the pollution problem can be largely solved.

Hereinafter, a method for plating a metal surface according to the present invention will be described in detail with reference to FIGS. 1 to 4 .

First, the object to be plated is degreased by immersing it in a degreasing solution containing sodium hydroxide and nitric acid. Foreign substances, oils and fats, and films adhering to the surface of the object to be cast may be removed through the degreasing step.

In one embodiment, the concentration of nitric acid may range from about 1 to about 65%. If the concentration of nitric acid is less than about 1%, foreign substances, oils, or films remaining on the surface of the material to be plated may not be sufficiently removed. damage may occur.

In one embodiment, the concentration of sodium hydroxide may range from about 10 to about 98%. If the concentration of sodium hydroxide is less than about 10%, foreign substances, oils, or films remaining on the surface of the material to be plated may not be sufficiently removed, and if it exceeds about 98%, damage to the object to be plated may occur. can

In one embodiment, the object to be plated may be used without limitation, and includes, for example, one or more selected from the group consisting of aluminum, manganese, magnesium, zinc, copper, zirconium, titanium, and combinations thereof. can do. Specifically, the object to be plated may be aluminum or an aluminum alloy.

Next, the degreased object to be plated is chemically etched using an etching solution. Through the chemical etching, a portion of the surface of the object to be plated may be melted to form fine irregularities, and the fine irregularities may be formed to improve adhesion of an oxide film formed later by an anchoring effect. The chemical etching step may be used without limitation as long as it is an etching solution and etching conditions typically used for chemical etching, and specifically, etching using an acid aqueous solution may be used.

In one embodiment, the acid aqueous solution may be carried out using an acid aqueous solution containing at least one selected from the group consisting of hydrochloric acid, nitric acid, sulfuric acid, and combinations thereof.

Next, the surface of the chemically etched object to be plated is matt. The matte treatment may be performed by corroding the surface of the object to be plated, and the corrosion method may be performed by physical corrosion or chemical corrosion. Specifically, the matte treatment may be performed by immersing the object to be plated in a chemical solution to chemically corrode the surface.

In one embodiment, the method may further include performing a secondary chemical etching by immersing the matt-treated object to be plated in an etching solution. By performing the chemical etching in two steps, it is possible to improve the adhesion between the object to be plated and the oxide film to be plated later, thereby preventing interlayer lifting, thereby improving the durability of the product. Specifically, secondary chemical etching may be performed by immersing the matt-treated object to be plated in a secondary chemical etching solution containing sodium hydroxide and ammonium fluoride.

Next, the matt-treated object to be plated is immersed in an electrolyte to form an oxide film on the surface of the object to be plated. By immersing the matt-treated object to be plated in an electrolyte containing an acid aqueous solution, connecting it to the anode, and then supplying power, the metal surface of the object to be plated is oxidized by oxygen generated from the anode to form an oxide film on the surface. it could be The electrolyte may include one or more selected from the group consisting of sulfuric acid, nitric acid, phosphoric acid, oxalic acid, chromic acid, oxalic acid, and combinations thereof, and specifically, sulfuric acid.

In one embodiment, the electrolyte may include about 10 to about 50% by weight of sulfuric acid. If the sulfuric acid is contained in an amount of less than about 10% by weight, the film may not be sufficiently formed, and when it exceeds about 50% by weight, damage to the object to be plated may occur.

In one embodiment, the thickness of the formed oxide film may be in the range of about 30 to about 100 μm. If the thickness of the oxide film is less than about 30 μm, durability and corrosion resistance may decrease, and if it exceeds about 100 μm, process cost and time may be excessively increased.

Next, the object to be plated on which the oxide film is formed is washed with water. The water washing may be repeated about two or more times, and foreign substances except for the object to be plated and the oxide film, for example, oil, grease, etc., may be removed through the washing.

Next, the object to be plated from which the foreign material has been removed is immersed in the dye composition to be colored. The dye composition may be used without limitation, and for example, by immersing the dye composition having a pH of about 5 to about 8 for about 1 minute to about 10 minutes, it is possible to color the object to be plated on which the oxide film is formed. If the pH of the dye composition is different from that described above, the object to be plated may not be uniformly colored. In addition, the dye composition may be used by mixing two or more dyes having the same concentration (pH), but is not limited thereto.

In one embodiment, during the steps of forming an oxide film on the surface of the object to be plated and coloring the object to be plated, the step of repeatedly spraying an adsorbent at intervals of about 1 hour to about 4 hours to remove contaminants may include For example, one or more selected from the group consisting of an acid component, carbon dioxide, a metal compound, a phosphorus compound, and combinations thereof by repeatedly spraying an adsorbent during the step of forming the oxide film and the coloring step of the object to be plated It can effectively adsorb and/or remove contaminants including Accordingly, by removing the contaminants generated in the plating process, it is possible to keep the safety of the workers and solve the pollution problem caused by the contaminants. If the spray is sprayed at an interval of less than about 1 hour, the humidity may be excessively increased, and if the spray is sprayed at an interval of more than about 4 hours, the effect of adsorption and removal of contaminants may decrease. Specifically, it may be performed at intervals of about 2 hours to about 3 hours, but is not limited thereto.

In one embodiment, the adsorbent may include powdery impregnated activated carbon. The activated carbon is made of carbonaceous material and has a strong adsorption property, and the activated carbon containing a specific material in order to increase the adsorption performance is referred to as impregnated activated carbon. Specifically, the adsorbent may be obtained by dispersing powdery impregnated activated carbon in a solvent. The solvent may be used without limitation as long as it is capable of dispersing the adsorbent, and may include, for example, purified water, lower alcohol, and the like.

In one embodiment, the powder-type impregnated activated carbon may be characterized in that one or more phosphorus adsorption materials are uniformly impregnated and included in the activated carbon. For example, the phosphorus adsorption material may be at least one selected from the group consisting of ferric chloride, ferric nitrate, ferrous sulfate, and combinations thereof, preferably, as a phosphorus adsorption material It may refer to powdery impregnated activated carbon in which ferric chloride is uniformly impregnated and included in the activated carbon. Accordingly, in the plating method according to the present invention, phosphorus compounds such as red lead generated during the process can be effectively removed by repeatedly spraying the adsorbent containing the powdery impregnated activated carbon.

In one embodiment, the powder-type impregnated activated carbon comprises the steps of: adding activated carbon to an aqueous solution containing the phosphorus adsorption material; heating and stirring an aqueous solution containing the phosphorus adsorption material and activated carbon to adsorb the phosphorus adsorbing material to the activated carbon; and drying and pulverizing the activated carbon to which the phosphorus adsorption material has been adsorbed.

For example, the powder-type impregnated activated carbon is obtained by adding activated carbon to an aqueous ferric chloride solution, and heating the aqueous solution to which the activated carbon is added at a temperature of about 50° C. to 150° C. while stirring at a speed of about 50 to about 500 rpm. Ferric chloride is adsorbed to the activated carbon, and the adsorbed activated carbon is evaporated to dryness in a dryer in a temperature range of about 60° C. to about 120° C. for about 1 hour to about 12 hours to dry, and then from about 50 to about 150 using a pulverizer. It may be obtained by pulverizing to have a particle size of the mesh.

In one embodiment, the particle size of the powder-type impregnated activated carbon may be in the range of about 50 to 150 mesh. If the particle diameter of the powder-type impregnated activated carbon exceeds about 50 mesh or less or about 150 mesh, the spraying may not be easily performed.

In an embodiment, the powdery impregnated activated carbon may be included in an amount of about 0.1 to about 10% by weight of the total amount of the adsorbent. If the powdery impregnated activated carbon is contained in an amount of less than about 0.1 wt%, the adsorption effect by the powdered impregnated activated carbon may not be sufficiently exhibited. there is.

In one embodiment, the adsorbent may further include a lithium compound-containing carbon dioxide adsorbent. For example, the carbon dioxide adsorbent may include a lithium compound selected from the group consisting of Li ₂ O, Li ₂ CO ₃ , LiOH, LiNO ₃ , LiCl, LiBr, and combinations thereof, and magnesium oxide (MgO). For example, the carbon dioxide adsorbent may include LiNO ₃ -MgO, which is a mixture of LiNO ₃ and magnesium oxide.

In an embodiment, the adsorbent further includes a lithium compound-containing carbon dioxide adsorbent, thereby removing carbon dioxide generated during the process to prevent climate change due to excessive greenhouse gas emission, thereby helping to protect the environment.

In one embodiment, the carbon dioxide adsorbent is Li ₂ O, Li ₂ CO ₃ , LiOH, LiNO ₃ , LiCl, LiBr, and a lithium compound salt selected from the group consisting of, and combinations thereof and magnesium oxide by mixing and calcining It may be manufactured. For example, the carbon dioxide adsorbent may be prepared by dispersing or dissolving a lithium compound salt in an organic solvent, mixing it with magnesium oxide, and calcining in a temperature range of about 300°C to about 500°C.

In an embodiment, the elemental ratio of lithium and magnesium in the carbon dioxide adsorbent may be Mg:Li=about 1: about 1 to 5. For example, as the elemental ratio of lithium and magnesium of the carbon dioxide adsorbent changes, the carbon dioxide adsorption rate may change, and specifically, when the elemental ratio of lithium increases, the carbon dioxide adsorption rate may increase.

In one embodiment, the carbon dioxide adsorbent may be included in an amount of about 0.1 to about 3 wt% of the total amount of the adsorbent. If the carbon dioxide adsorbent is included in an amount of less than about 0.1 wt%, the carbon dioxide adsorption effect may not be sufficiently exhibited, and when it is included in an amount exceeding about 3 wt%, the manufacturing cost may be excessively increased.

In one embodiment, the adsorbent may further include a surface-modified zeolite adsorbent. The zeolite is a mineral having a property of adsorbing heavy metals and toxic substances, and the adsorption property can be improved by surface modification of the zeolite. Accordingly, in the plating method according to the present invention, by repeatedly spraying the surface-modified zeolite adsorbent during the process, it is possible to effectively adsorb and remove pollutants including heavy metals and harmful gases including phosphorus compounds generated during the process.

In one embodiment, the surface-modified zeolite is prepared by adding the zeolite to an aqueous solution of sulfuric acid; taking out the zeolite immersed in the sulfuric acid aqueous solution and calcining to form a sulfate salt on the surface of the zeolite; and drying and pulverizing the zeolite in which the sulfate is formed.

In one embodiment, the surface-modified zeolite may be included in an amount of about 0.1 to about 10% by weight of the total amount of the adsorbent. If the surface-modified zeolite is included in an amount of less than about 0.1 wt%, the adsorption effect by the zeolite may not be sufficiently exhibited, and if it is included in an amount exceeding about 10 wt%, the manufacturing cost may increase excessively.

In one embodiment, the firing may be performed at a temperature range of about 250 °C to about 350 °C. If the calcination is performed at a temperature of less than about 250° C., sulfate may not be uniformly formed on the surface of the zeolite, and if it exceeds about 350° C., excessive calcination may result in deterioration of the adsorption performance of the zeolite.

Next, the colored object to be plated is sealed and surface treated. The film formed through the anodization may adsorb gas in the air and eventually change to an inert state if left as it is with a great active force at the initial stage of formation. Therefore, by sealing the object to be plated on which the oxide film is formed and performing surface treatment, the hole formed on the surface of the film is blocked to improve corrosion resistance, anti-contamination ability, stability, and weather resistance.

In one embodiment, between each step selected from the degreasing step, the chemical etching step, the matting step, the oxide film forming step, the coloring step, and the surface treatment step, the to-be-plated object is washed with water about twice or more A washing step of washing may be further included.

Hereinafter, the configuration of the present invention and its effects will be described in more detail through specific examples and comparative examples. However, these examples are for explaining the present invention in more detail, and the scope of the present invention is not limited to these examples.

[Example 1]

The aluminum alloy material to be plated (FIG. 1a) was degreased by immersing it in a degreasing solution at 50° C. containing sodium hydroxide (98%) and 20% nitric acid aqueous solution as a cationic surfactant for 5 minutes (FIG. 1b). The degreased object to be plated was chemically etched by immersion in 20% sulfuric acid for 1 minute and then washed with water (FIG. 1c). After that, the object to be plated is immersed in a solution containing solution C and solution D for 5 minutes to polish the surface (FIG. 1d), and then add 1 to an etching solution containing sodium hydroxide (98%) and ammonium fluoride. Secondary chemical etching was performed by immersion for minutes. Next, the object to be plated was immersed in a solution containing 20% by weight of sulfuric acid at a temperature of 25° C. for 50 minutes to form an oxide film on the surface of the object to be plated using the object to be plated as an anode (FIG. 2a).

After the oxide film was formed, it was washed twice with water (Fig. 2b), and was colored by immersion in a solution containing ALUMINARL ORANGE-W as a dye composition for 20 minutes (Fig. 2c). The dye-colored object to be plated was immersed in a sealing agent for preventing discoloration (ANOD SG) for 20 minutes to perform a sealing treatment (FIG. 2d). After the sealing treatment, dehydration, drying, and inspection were performed as shown in FIG. 3 to complete the plating treatment, and this was named Example 1 (FIG. 4).

[Example 2 and Example 3]

The same as in Example 1, except that in the step of forming an oxide film and coloring the object to be plated, the step of repeatedly spraying the adsorbent composed of the components shown in Table 1 below at 2 hour intervals was added to complete the plating treatment, 2 and Example 3.

Adsorbent Components Example 2 Example 3 Powder type impregnated activated carbon 10.00 10.00 LiNO ₃ -MgO 2.50 2.50 Surface modified zeolite - 4.50 Purified water remaining amount remaining amount

[Comparative example]

Without plating, an aluminum alloy material covered with a natural oxide film was obtained by simple injection molding, and this was named as a comparative example.

[Experimental Example 1: Durability comparison experiment]

Each of the aluminum materials of Examples 1 to 3 and Comparative Examples were tested for durability. For the durability test, the aluminum material with an oxide film was exposed to ultraviolet rays of 254 mm for about 15 minutes, and then the appearance was observed with the naked eye and the results were recorded. As for the evaluation criteria, the case where the appearance did not change was marked as '○', the case where the bending phenomenon of less than 15° was indicated as '△', and the case where severe distortion and browning occurred was marked with 'x'. The results are shown in Table 2 below.

Example 1 Example 2 Example 3 comparative example Durability measurement result ○ ○ ○ ×

As shown in Table 2, in the case of the aluminum material by the plating method according to the present invention, it was confirmed that it showed excellent durability despite UV irradiation.

[Experimental Example 2: Measurement of Oxide Film Thickness]

The oxide film thickness of each of the aluminum materials of Examples 1 to 3 and Comparative Examples was measured through a coating film measuring device. The measurement results are shown in Table 3 below.

Example 1 Example 2 Example 3 comparative example Oxide film thickness (μm) 26.8 34.5 41.0 5.1

As shown in Table 3, in the case of the aluminum material by the plating method according to the present invention, it was confirmed that a significantly thicker oxide film was formed compared to the natural oxide film.

[Experimental Example 3: Electrochemical analysis]

The weight change rate was measured by immersing the aluminum materials of Examples 1 to 3 and Comparative Examples in sodium chloride solution, respectively. Specifically, each of the aluminum materials was immersed in a 3.5 wt% NaCl aqueous solution at 25° C., and electrochemical analysis was performed using a weight change rate for 3 days in units of 24 hours. The weight loss and average are shown in Table 4 below.

initial weight primary mass
(reduction amount) Day 2 Mass
(reduction amount) Day 3 Mass
(reduction amount) Example 1 5.371 5.367 (0.004) 5.363
(0.004) 5.355
(0.008) Example 2 5.780 5.778
(0.002) 5.774
(0.004) 5.770
(0.004) Example 3 5.179 5.178 (0.001) 5.177
(0.001) 5.175
(0.002) comparative example 5.479 5.470 (0.009) 5.458
(0.012) 5.435
(0.023)

As shown in Table 4, the weight loss of the aluminum material by the coating film treatment method according to the present invention was smaller than that of the comparative example. This means that oxidation is less advanced by the oxide film formed through anodization, and thus, it can be confirmed that the corrosion resistance of the aluminum material is improved.

In this specification, only a few examples among the various embodiments performed by the present inventors are described, but the technical spirit of the present invention is not limited or limited thereto, and it is of course that it may be modified and variously implemented by those skilled in the art.

Claims (3)

degreasing the object to be plated by immersing it in a degreasing solution containing sodium hydroxide in a concentration range of 10 to 98% and nitric acid in a concentration range of 1 to 65%;
first chemical etching the degreased object to be plated using an acid aqueous solution;
eroding the surface of the chemically etched object to be plated;
Secondary chemical etching by immersing the matt-treated object to be plated in an etching solution containing sodium hydroxide and ammonium fluoride;
immersing the matt-treated object to be plated in an electrolyte containing 10 to 50 wt% of sulfuric acid to form an oxide film having a thickness of 30 to 100 μm on the surface of the object to be plated;
removing foreign substances by washing the object to be plated on which the oxide film is formed;
immersing the object to be plated from which the foreign material has been removed in a dye composition to color it; and
sealing and surface-treating the colored object to be plated;
As a plating method of a metal surface comprising a,
During the steps of forming an oxide film on the surface of the object to be plated and coloring the object to be plated, 0.1 to 10% by weight of powdered impregnated activated carbon in which ferric chloride is evenly impregnated and contained in activated carbon as a material for phosphorus adsorption; and Removal of contaminants by repeatedly spraying an adsorbent containing 0.1 to 3 weight of LiNO ₃ -MgO as a carbon dioxide adsorbent at intervals of 1 to 4 hours,
The adsorbent contains 0.1 to 10 wt% of the powdery impregnated activated carbon in which ferric chloride is uniformly impregnated and contained in the activated carbon as a phosphorus adsorption material, based on the total weight of the adsorbent, and LiNO ₃ -MgO as the carbon dioxide adsorbent is used in the entire adsorbent Characterized in that it contains 0.1 to 3 weight based on the weight,
A method for plating a metal surface.
delete According to claim 1, wherein the to-be-plated object,
A method for plating a metal surface, comprising at least one selected from the group consisting of aluminum, manganese, magnesium, zinc, copper, zirconium, titanium, and combinations thereof.

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