KR20200056664A - Surface treatment Method of Magnesium member and Magnesium Product - Google Patents

Abstract

The present invention relates to a method for treating a magnesium member surface, comprising: a magnesium member preparing step of providing a magnesium member including magnesium; Forming a PEO oxide layer on the surface of the magnesium member by plasma electrolytic oxidation; It characterized in that it comprises; a metal layer forming step of forming a metal layer having a predetermined thickness on the upper surface of the PEO oxide layer.
According to the present invention, even if the surface of the magnesium member has a complicated shape, the PEO oxide film layer excellent in corrosion resistance, abrasion resistance, and electrical insulation can be uniformly formed, and the PEO oxide film layer is adhered to the magnesium member and the metal layer There is an effect that a method for treating a surface of a magnesium member having excellent properties can be obtained.

Description

Surface treatment method of Magnesium member and Magnesium product

The present invention relates to a method for treating a surface of a magnesium member, and in particular, even if the surface of the magnesium member has a complicated shape, a PEO oxide layer having excellent corrosion resistance, abrasion resistance and electrical insulation can be uniformly formed, and the PEO oxide layer and the magnesium It relates to a method for treating a surface of a magnesium member having excellent adhesion properties between a member and a metal layer.

The magnesium member is a lightweight material, but has poor corrosion resistance, and thus has many limitations for use as an auto parts material. In the case of magnesium alloys produced in Korea, it is generally produced as a plate material, and it is easy to generate oxides or oxide films as impurities on the surface when it meets oxygen in the atmosphere. However, there is a problem in that surface quality is not good by causing film defects.

Therefore, it is very important to remove the impurity oxide of the magnesium member in the surface treatment of magnesium, and this pre-treatment process has become an essential process for eliminating secondary problems.

In general, when removing the impurity oxide film on the magnesium surface, a lot of chemical solutions are used to maintain the surface uniformity of the material. The etching solution used at this time may also include glacial acetic acid and nitrate.

However, even if the impurity oxide film generated on the surface of the magnesium member is removed with a chemical solution, the material such as magnesium alloy has a problem that oxidation easily proceeds in an atmospheric environment or in a wet surface treatment process. In particular, there is also a problem that the impurity oxide film produced by contact with the atmosphere is very thin and has poor adhesion to a primer layer or a metal layer.

Therefore, since the stable operation of the subsequent process is difficult only by removing the impurity oxide film by the chemical solution, an additional surface treatment process for stabilizing the subsequent process is required.

The present invention has been devised to solve the above problems, and its purpose is to uniformly form a PEO oxide film layer excellent in corrosion resistance, abrasion resistance and electrical insulation even if the surface of the magnesium member has a complicated shape, and the PEO oxide film layer It is to provide an improved method for treating the surface of the magnesium member to improve the adhesion properties between the magnesium member and the metal layer.

Another object of the present invention is to provide an improved magnesium processed product so that the PEO oxide layer and the magnesium member and the metal layer have excellent adhesion properties.

In order to achieve the above object, a method for treating a surface of a magnesium member according to the present invention includes a magnesium member preparing step of providing a magnesium member including magnesium; Forming a PEO oxide layer on the surface of the magnesium member by plasma electrolytic oxidation; It characterized in that it comprises; a metal layer forming step of forming a metal layer having a predetermined thickness on the upper surface of the PEO oxide layer.

Here, the preparing the magnesium member may include: removing an impurity oxide film formed on the surface of the magnesium member; After performing the impurity oxide film removal step, it is preferable to include; a first cleaning step of removing impurities remaining on the surface of the magnesium member using a cleaning solution.

Here, in the step of forming the PEO oxide layer, the PEO oxide layer is preferably formed of a porous layer having a thickness of 5 to 15㎛.

Here, in the metal layer forming step, it is preferable that the metal layer is formed on the top surface of the PEO oxide layer by a thermal resistance deposition method.

Here, after performing the PEO oxide film forming step, a second cleaning step of removing impurities remaining on the surface of the PEO oxide layer using a cleaning solution; A primer layer forming step of forming a primer layer having a predetermined thickness on the top surface of the PEO oxide layer; After performing the primer layer forming step, it is preferable to further include a drying step of removing the residual moisture to dry the surface of the primer layer.

Here, after performing the metal layer forming step, it is preferable to further include a protective layer forming step of forming a protective layer for protecting the metal layer.

Magnesium processed product according to the present invention to achieve the other object, the magnesium member; A PEO oxide layer formed on the surface of the magnesium member by a plasma electrolytic oxidation technique; It characterized in that it comprises; a metal layer formed to have a predetermined thickness on the upper surface of the PEO oxide layer.

Here, the PEO oxide layer is formed of a porous layer having a thickness of 5 to 15㎛, the metal layer is formed on the upper surface of the PEO oxide layer by a thermal resistance deposition method, the predetermined thickness on the upper surface of the PEO oxide layer A primer layer formed to have a; It is preferable to further include; a protective layer formed on the upper surface of the metal layer.

According to the present invention, a magnesium member preparing step of providing a magnesium member including magnesium; Forming a PEO oxide layer on the surface of the magnesium member by plasma electrolytic oxidation; Since the metal layer forming step of forming a metal layer having a predetermined thickness on the upper surface of the PEO oxide layer; including, even if the surface of the magnesium member has a complex shape, the corrosion resistance, abrasion resistance, uniformity of the PEO oxide layer excellent in electrical insulation It can be formed, there is an effect that it is possible to obtain a magnesium member surface treatment method having excellent adhesion properties between the PEO oxide layer and the magnesium member and the metal layer.

1 is a flowchart illustrating a method of treating a surface of a magnesium member, which is an embodiment of the present invention.
2 is a cross-sectional view showing a magnesium processed product according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a flow chart for explaining a magnesium member surface treatment method according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view showing a magnesium processed product according to an embodiment of the present invention.

1 to 2, a method for treating a surface of a magnesium member according to a preferred embodiment of the present invention is a method for treating a surface of a magnesium member that can be used as a member such as an engine compartment cover for automobile parts, and a step of providing a magnesium member , PEO oxide film layer forming step (S30), second cleaning step (S40), primer layer forming step (S50), drying step (S60), metal layer forming step (S70), protective layer forming step (S80) ).

The preparing of the magnesium member is a step of preparing a magnesium member 10 including magnesium, and in the present embodiment, the preparing of the magnesium member includes an impurity oxide film removing step (S10) and a first cleaning step (S20). . Hereinafter, it will be described on the assumption that the magnesium member 10 is a magnesium plate material formed by a high-frequency heat press technique and has a thickness of approximately 0.5 to 3 mm.

The impurity oxide film removal step (S10) is a step of removing the impurity oxide film formed on the surface of the magnesium member 10. In this embodiment, the impurity oxide film is removed using an etching solution. The acidic etching solution used for this contains 100-1000 ml / L glacial acetic acid and 30-60 ml / L sodium nitrate with respect to 1000 ml / L of water.

When the surface treatment is performed for 30 to 300 seconds at an atmospheric temperature using the etching solution, the chemical etching of the surface of the magnesium member 10 can be uniformly performed within 0.05 to 4 μm.

On the other hand, an alkali etching solution may be used instead of the acidic etching solution, wherein the alkali etching solution comprises 20 to 80% by weight of triethanolamine, 5 to 40% by weight of ethylenediaminetetraacetic acid (EDTA) and 20 to 40% by weight of sodium hydroxide. It can contain.

When using the alkali etching solution, it is preferable to deposit for 2 to 8 minutes at a pH range of 9 to 10.5 and atmospheric temperature.

When using the acidic etching solution, it has a feature of uniformizing the surface energy, and also serves to stabilize the magnesium member 10 during a chemical reaction. By using such an acidic etching solution, a uniform chemical reaction can be caused at the time of forming the PEO oxide film layer 20 to be described later, and a relatively dense PEO oxide film layer 20 can be obtained. (Impurity oxide film removal step; S10)

The first cleaning step (S20) is a step of removing impurities remaining on the surface of the magnesium member 10 using a cleaning solution after the impurity oxide film removal step (S10) is performed.

The first cleaning step (S20), the main purpose is to remove the etching solution remaining on the surface of the magnesium member 10. In this embodiment, distilled water is used to remove the impurities, and the conductivity of the distilled water is 0.065 to 0.045 Pa / cm and resistance 17 to 19 Pa / cmD. (First cleaning step; S20)

The PEO oxide layer forming step (S30) is a step of forming the PEO oxide layer 20 on the surface of the magnesium member 10 after performing the first cleaning step (S20). In this embodiment, a plasma electrolytic oxidation method (PEO; Plasma Electrolytic Oxidation) is used to form the PEO oxide layer 20.

The plasma electrolytic oxidation method (hereinafter referred to as “PEO method”) generally forms a PEO oxide layer by applying a high voltage pulse of 300 to 600 V in a water-soluble electrolyte solution, and is applied to a micro arc plasma generated on a metal surface due to high voltage. It is normal for the molten metal to be oxidized to become a surface coating.

In this embodiment, the electrolyte is, for 1000 g of pure water, potassium hydroxide (KOH) 0.4 to 2 g, sodium phosphate (Na ₃ PO ₄ ) 1 to 15 g, sodium hydroxide (NaOH) 200 to 300 g, aluminum powder 1 to 3 g It contains.

On the other hand, in this embodiment, instead of a high voltage of 300 to 600 V, a low voltage of 50 to 70 V is used, the current is approximately 30 to 40 A, and the time for applying the current is 3 to 5 minutes.

In this embodiment, the PEO oxide layer 20 is formed of a porous layer having a thickness of 5 to 15㎛.

When the PEO method is used, a uniform PEO oxide film layer 20 can be formed on a surface having a complicated shape, and excellent adhesion properties between the formed PEO oxide film layer 20 and the magnesium member 10 as a base material can be maintained. , The PEO oxide layer 20 is excellent in corrosion resistance, abrasion resistance, electrical insulation, and the like, and adhesion of paint or paint by post-processing can be improved. (PEO oxide layer forming step; S30)

The second cleaning step (S40) is a step of removing the impurities remaining on the surface of the PEO oxide layer 20 by using a cleaning solution after performing the PEO oxide film forming step (S30).

The second cleaning step (S40), the main purpose is to remove the electrolyte solution remaining on the surface of the PEO oxide layer 20. In this embodiment, distilled water is used to remove the impurities, and the conductivity of the distilled water is 0.065 to 0.045 Pa / cm and resistance 17 to 19 Pa / cmD. (Second washing step; S40)

The primer layer forming step (S50) is a step of forming a primer layer 30 having a predetermined thickness on an upper surface of the PEO oxide layer 20.

The primer layer 30, alkyd resin, phthalic acid resin, acrylic resin, epoxy resin, polyurethane resin, vinyl chloride resin, silicone resin, fluorine resin, melamine resin, isocyanate resin, Kuroman resin, petroleum resin, rosin, nose At least selected from the group consisting of parous resin, cerac resin, oil alkyd, chlorinated rubber lacquer resin, silicate resin, unsaturated polyester resin, amino alkyd, polyester, urea, fluorine, vinyl acetate, vinyl chloride, acrylic synthetic rubber, and epoxy. It is preferred to include one. In this embodiment, the primer layer 30 contains a polyurethane resin, and the thickness is 8-25 µm. (Primer layer forming step; S50)

The drying step (S60) is a step of drying the surface of the primer layer 30 by removing the residual moisture after performing the primer layer forming step (S50). In this embodiment, it is dried using hot air at a temperature of 75 to 90 ° C. (Drying step; S60)

The metal layer forming step (S70) is a step of forming a metal layer 40 having a predetermined thickness on the upper surface of the primer layer 30.

In this embodiment, the metal layer 40 is formed on the upper surface of the primer layer 30 by a thermal resistance deposition method, which is one of vacuum deposition methods.

The thermal resistance deposition method is a type of physical vapor deposition (PVD) for depositing a deposition material on a surface of an object to be deposited in a vacuum at a predetermined thickness, and a heating wire heated when electricity flows. To vaporize the deposited material. The thermal resistance deposition method is well known to those skilled in the art, so a detailed description thereof will be omitted.

First, the surface of the primer layer 30 is modified by a plasma pretreatment method before the heat resistance deposition method is performed. At this time, the vacuum degree is 8 × 10 ^-5 torr, the gas amount is 500 sccm, and the cleaning time is about 180 seconds.

Subsequently, under a condition of a vacuum degree of 5 × 10 ⁻⁵ torr, a current is passed through a heating wire or the like to vaporize the deposition material, and the vaporized deposition material is deposited on the upper surface of the primer layer 30. At this time, a metal that can be used as a deposition material (target) is aluminum (Al). SUS. Tin (Sn). Copper (Cu). Titanium (Ti). Silver (Ag). Chromium (Cr). Nickel (Ni). And at least one selected from the group consisting of molybdenum (Mo). (Metal layer forming step; S70)

The protective layer forming step (S80) is a step of forming the protective layer 50 for protecting the metal layer 40 after performing the metal layer forming step (S70).

The protective layer 50, alkyd resin, phthalic acid resin, acrylic resin, epoxy resin, polyurethane resin, vinyl chloride resin, silicone resin, fluorine resin, melamine resin, isocyanate resin, Kuroman resin, petroleum resin, rosin, nose Parus resin, Serak resin, oil alkyd, chlorinated rubber lacquer resin, silicate resin. It is formed by coating at least one selected from the group consisting of unsaturated polyester resin, amino alkyd, polyester, urea, fluorine, vinyl acetate, vinyl chloride, acrylic synthetic rubber, and epoxy, on the top surface of the metal layer 40.

The protective layer 50 may be formed in a transparent or translucent state, or may be formed to include a color paint or a stain paint of a predetermined color.

Here, the color paint to the stain paint, coloring pigments (zinc, titanium, yellow, carbon black), metal powder (silver powder, gold powder, aluminum, alloy minerals), sieving pigment (calcium carbonate, talc, barium sulfate, silica) , Zion pigment may be used at least one selected from the group consisting of.

Thus, the protective layer 50 is formed on the metal layer 40, thereby completing the magnesium processed product 100. (Step of forming a protective layer; S80)

When the above-described magnesium member surface treatment method is used, as shown in FIG. 2, the magnesium member 10, a PEO oxide film layer 20 formed on the surface of the magnesium member 10 by the plasma electrolytic oxidation technique, the A primer layer 30 formed to have a predetermined thickness on the upper surface of the PEO oxide layer 20, a metal layer 40 formed to have a predetermined thickness on the upper surface of the primer layer 30, and an upper surface of the metal layer 40 It is possible to manufacture a magnesium processed product 100 having a protective layer 50 formed on.

The above-described magnesium member surface treatment method includes a magnesium member provision step of providing a magnesium member 10 containing magnesium; A PEO oxide film layer forming step (S30) of forming a PEO oxide film layer 20 on the surface of the magnesium member 10 by plasma electrolytic oxidation technique; Since the metal layer forming step (S70) of forming a metal layer 40 having a predetermined thickness on the upper surface of the PEO oxide layer 20; includes, corrosion resistance even if the surface of the magnesium member 10 has a complex shape, The PEO oxide film layer 20 having excellent abrasion resistance and electrical insulation can be uniformly formed, and the PEO oxide film layer 20 and the magnesium member 10 and the metal layer 40 have excellent adhesion properties. have.

And the magnesium member surface treatment method, the magnesium member providing step, the impurity oxide film removal step of removing the impurity oxide film formed on the surface of the magnesium member 10 (S10); After performing the impurity oxide film removal step (S10), a first cleaning step (S20) of removing impurities remaining on the surface of the magnesium member 10 using a cleaning solution; includes, so that the impurity oxide film There is an advantage in that the adhesion between the magnesium member 10 and the PEO oxide layer 20 is not deteriorated, and film defects are not induced, thereby improving the surface quality.

In addition, in the method of treating the surface of the magnesium member, in the step of forming the PEO oxide layer (S30), the PEO oxide layer 20 is formed of a porous layer having a thickness of 5 to 15 μm, so that the primer layer 30 and the metal layer ( 40) is penetrated and fixed to the porous layer, there is an advantage that the adhesion between the primer layer 30 and the metal layer 40 is increased.

And the magnesium member surface treatment method, in the metal layer forming step (S70), the metal layer 40 is formed on the upper surface of the PEO oxide layer 20 by a thermal resistance deposition method, the configuration of the deposition apparatus is relatively simple And, there is an advantage that it is easy to use a large number of deposition materials.

In addition, the magnesium member surface treatment method, after performing the PEO oxide film forming step (S30), using a cleaning solution to remove impurities remaining on the surface of the PEO oxide layer 20 (S40); A primer layer forming step (S50) of forming a primer layer 30 having a predetermined thickness on the top surface of the PEO oxide layer 20; After performing the primer layer forming step (S50), removing the residual moisture to dry the surface of the primer layer 30 (S60); further comprising, so, the surface of the PEO oxide layer 20 Even if it is not smooth due to low smoothness, it is possible to increase the smoothness of the upper surface of the primer layer 20, so that the metal layer 40 can be formed smoothly, and the metal layer 40 is formed by the primer layer 30. The PEO oxide layer 20 has an advantage that can be more firmly attached.

And the magnesium member surface treatment method, after performing the metal layer forming step (S70), the protective layer forming step (S80) for forming a protective layer 50 for protecting the metal layer 40; , It is possible to prevent the metal layer 40 from being damaged by an external impact, and there is an advantage that a decorative effect by the protective layer 50 can be generated.

The above-described magnesium processed product 100 includes a magnesium member 10; PEO oxide film layer 20 formed on the surface of the magnesium member 10 by plasma electrolytic oxidation technique; Since the metal layer 40 formed to have a predetermined thickness on the upper surface of the PEO oxide layer 20, including, even if the surface of the magnesium member 10 has a complex shape, excellent corrosion resistance, wear resistance, electrical insulation The PEO oxide layer 20 can be uniformly formed, and there is an advantage in that the PEO oxide layer 20 and the magnesium member 10 and the metal layer 40 have excellent adhesion properties.

And the magnesium processed product 100, the PEO oxide layer 20 is formed of a porous layer having a thickness of 5 to 15㎛, the metal layer 40 of the PEO oxide layer 20 by the thermal resistance deposition method A primer layer 30 formed on an upper surface and having a predetermined thickness on the upper surface of the PEO oxide layer 20; Since it further comprises a protective layer 50 formed on the upper surface of the metal layer 40, it is possible to increase the smoothness of the upper surface of the primer layer 20, to smoothly form the metal layer 40, external impact By doing so, it is possible to prevent the metal layer 40 from being damaged, and there is an advantage that a decorative effect by the protective layer 50 can be generated.

The present invention has been described above, but the technical scope of the present invention is not limited to the contents described in the above-described embodiments, and the equivalent configuration modified or changed by a person having ordinary knowledge in the relevant technical field is technical of the present invention. It is clear that it is within the scope of thought.

＊ Explanation of codes for the main parts of the drawing ＊
100: magnesium processed product
10: absence of magnesium
20: PEO oxide layer
30: primer layer
40: metal layer
50: protective layer

Claims (8)

A magnesium member preparation step of preparing a magnesium member including magnesium;
Forming a PEO oxide layer on the surface of the magnesium member by plasma electrolytic oxidation;
Metal layer forming step of forming a metal layer having a predetermined thickness on the upper surface of the PEO oxide layer; Magnesium member surface treatment method comprising a According to claim 1,
The magnesium member preparation step,
An impurity oxide film removing step of removing the impurity oxide film formed on the surface of the magnesium member;
After the impurity oxide film removal step, a first cleaning step of removing impurities remaining on the surface of the magnesium member using a cleaning solution; Magnesium member surface treatment method comprising a According to claim 1,
In the step of forming the PEO oxide layer, the PEO oxide layer is formed of a porous layer having a thickness of 5 to 15 μm, and the method of treating the surface of the magnesium member is characterized in that According to claim 1,
In the metal layer forming step,
The metal layer is formed on the upper surface of the PEO oxide layer by a thermal resistance deposition method, characterized in that the magnesium member surface treatment method According to claim 1,
After performing the PEO oxide film forming step, a second cleaning step of removing impurities remaining on the surface of the PEO oxide layer using a cleaning solution;
A primer layer forming step of forming a primer layer having a predetermined thickness on the top surface of the PEO oxide layer;
A drying step of drying the surface of the primer layer by removing residual moisture after performing the primer layer forming step;
Magnesium member surface treatment method characterized in that it further comprises According to claim 1,
After performing the metal layer forming step, forming a protective layer for forming a protective layer for the protection of the metal layer; Magnesium member surface treatment method further comprising a Absence of magnesium;
A PEO oxide layer formed on the surface of the magnesium member by a plasma electrolytic oxidation technique;
Magnesium processed product comprising a; metal layer formed to have a predetermined thickness on the upper surface of the PEO oxide layer The method of claim 7,
The PEO oxide layer is formed of a porous layer having a thickness of 5 to 15㎛,
The metal layer is formed on the top surface of the PEO oxide layer by a thermal resistance deposition method,
A primer layer formed to have a predetermined thickness on the top surface of the PEO oxide layer;
Magnesium processed product further comprising; a protective layer formed on the upper surface of the metal layer

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