KR20140094678A - Method for surface-treating aluminium alloy and aluminium alloy cover having pattern for electronic article - Google Patents

Abstract

According to the disclosed method for a surface-treating aluminum alloy, an aluminum alloy molding is anodized, and a mask is formed on the surface of the anodized aluminum alloy molding. The aluminum alloy molding formed with the mask is etched to form a pattern on the surface thereof. The aluminum alloy molding with the pattern is anodized, and the anodized aluminum alloy molding is colored.

Description

METHOD FOR SURFACE-TREATING ALUMINUM ALLOY AND ALUMINUM ALLOY COVER HAVING PATTERN FOR ELECTRONIC ARTICLE BACKGROUND OF THE INVENTION 1. Field of the Invention [0001]

More particularly, the present invention relates to a surface treatment method of an aluminum alloy and an aluminum alloy cover for an electronic product having a pattern produced using the method.

The aluminum anodizing process is an electrochemical process used for corrosion resistance, abrasion resistance, electrical insulation and aesthetic characteristics. The oxide layer produced by this process has a very strong strength and pore structure which can be colored. Anodizing has the following advantages compared to painting or physical vapor deposition (PVD). Painting is not sustainable and does not comply with Restriction of Hazardous Substances (RoHS), which regulates the heavy metals and toxic substances specified by the European Union. In addition, PVD has a very low degree of freedom in color selection and very low process stability required in mass production.

Therefore, anodic oxidation, that is, anodizing, which forms an oxide film having high adhesion with a base metal by oxygen generated from the anode is widely utilized. The oxidation film formed by anodizing is excellent in corrosion resistance and abrasion resistance, and has excellent durability with excellent adhesion with base metal. In addition, due to the advantage of obtaining a decorative ornamental appearance through low cost coloring process in which a porous layer of an oxide film is filled with a dye and sealed, the use thereof is particularly increased in relation to aluminum and its alloys .

However, in the case of the anodized aluminum alloy, the surface treatment of uniform and beautiful colors is not easy, and simple coloring has a limitation in expressing various designs required for an electronic product cover.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and it is an object of the present invention to provide a method of treating a surface of an aluminum alloy which can realize uniform and beautiful colors and enable various designs through patterning.

It is also an object of the present invention to provide an aluminum alloy cover for an electronic product that can be obtained through a surface treatment method of the aluminum alloy.

According to the method for surface treatment of an aluminum alloy according to the embodiment for realizing the object of the present invention, an aluminum alloy molded article is anodized. A mask is formed on the surface of the anodized aluminum alloy molding. The aluminum alloy moldings on which the mask is formed are etched to form a pattern on the surface. Anodized aluminum alloy moldings having the above pattern are anodized. The anodized aluminum alloy molding is colored.

According to one embodiment, the aluminum alloy shaped article comprises 1.0 to 5.0% by weight of Mn, 0.5 to 1.5% by weight of Zn, 1.0 to 2.0% by weight of Zr, 0.5 to 1.5% by weight of Cu and extra aluminum.

According to one embodiment, the mask is formed by providing a solvent-type eco-direct ink on the surface of the aluminum alloy molding using a printer.

According to one embodiment, the mask has a thickness of 10 [mu] m to 30 [mu] m.

According to one embodiment, the step of etching the aluminum alloy mold comprises a first etching step of applying an alkali solution and a second etching step of applying an acid solution.

According to one embodiment, the acid solution comprises phosphoric acid or sulfuric acid.

According to one embodiment, the step of coloring the anodized aluminum alloy moldings comprises using a printer to provide an ink comprising a pigment.

According to one embodiment, the method further comprises sealing the colored aluminum alloy mold.

According to one embodiment, the aluminum alloy molding is a press-processed product or an extrusion-processed product.

An aluminum alloy cover for an electronic product according to an embodiment for realizing the object of the present invention described above is formed of an aluminum alloy, has an anodized film, and has a colored pattern formed on the surface by etching.

According to the present invention, an aluminum alloy product having a pattern with a smooth profile and a uniform color design can be produced by forming a mask using an ink in an anodized molded product and etching using a thickness gradient.

In addition, various designs can be realized by forming a mask and coloring using a printer.

FIG. 1 is a process flow chart for explaining a surface treatment method of an aluminum alloy according to an embodiment of the present invention.
FIGS. 2 to 4 are cross-sectional views illustrating a surface treatment method of an aluminum alloy according to an embodiment of the present invention.
5 is a photograph of a specimen produced according to a method of surface treatment of an aluminum alloy according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the drawings. The present invention is capable of various modifications and various forms, and specific embodiments are illustrated in the drawings and described in detail in the text. It should be understood, however, that the invention is not intended to be limited to the particular forms disclosed, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. Like reference numerals are used for like elements in describing each drawing. In the accompanying drawings, the dimensions of the structures are enlarged to illustrate the present invention in order to clarify the present invention. The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component. The singular expressions include plural expressions unless the context clearly dictates otherwise.

In this application, the terms "comprises", "having", and the like are used to specify that a feature, a number, a step, an operation, an element, a part or a combination thereof is described in the specification, But do not preclude the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof.

FIG. 1 is a process flow chart for explaining a surface treatment method of an aluminum alloy according to an embodiment of the present invention. FIGS. 2 to 4 are cross-sectional views illustrating a surface treatment method of an aluminum alloy according to an embodiment of the present invention. 5 is a photograph of a specimen produced according to a method of surface treatment of an aluminum alloy according to an embodiment of the present invention.

According to the surface treatment method of an aluminum alloy according to an embodiment of the present invention, an aluminum alloy is first prepared (S 10). In this embodiment, the aluminum alloy is an aluminum alloy for die casting, but in other embodiments it can be applied to all aluminum alloys capable of anodic oxidation and coloring with a pressed and extruded workpiece. Aluminum alloys capable of anodic oxidation and coloring by the above-mentioned press-processed and extruded products can be used according to conventional techniques.

The aluminum alloy for die casting includes 1.0 to 5.0% by weight of Mn, 0.5 to 1.5% by weight of Zn, 1.0 to 2.0% by weight of Zr, 0.5 to 1.5% by weight of Cu and 85 to 97% by weight of aluminum. The aluminum alloy for die casting contains 1 to 5% by weight of Mn as an essential component. The Mn component plays a role of precipitating Mn-Al6 phase from the alloy to improve the mechanical properties of the alloy through solubility enhancement and dispersion of fine precipitates, and is preferably in the range of 1.0 to 5.0% by weight based on the total weight of the entire alloy Is preferably added. If the Mn content is less than 1% by weight based on the total weight of the entire alloy, the improvement of the mechanical properties is insignificant, whereas if the Mn content exceeds 5.0% by weight, surface anomalies occur after anodizing.

In addition, the aluminum alloy for die casting of the present invention contains 0.5 to 1.5% by weight of Zn. The Zn component serves to improve the mechanical properties and is preferably added in the range of 0.5 to 1.5 wt% based on the total weight of the entire alloy.

Further, the aluminum alloy for die casting of the present invention contains 1.0 to 2.0% by weight of Zr. The Zr component can be anodically oxidized in the alloy, and serves to improve grain refinement and mechanical properties, and is preferably added in the range of 1.0 to 2.0 wt% based on the total weight of the entire alloy.

Further, the aluminum alloy for die casting of the present invention contains 0.5 to 1.5 wt% of Cu. The Cu component is dissolved in the alloy in the alloy so as to strengthen the matrix and prevent the mold from sticking. The Cu component plays a role of increasing the strength by excellent precipitation hardening effect at low temperature aging, preferably 0.5 to 1.5 By weight.

The description of aluminum is known to those of ordinary skill in the art to which the present invention belongs, so that no further description will be given herein.

The aluminum alloy for die casting of the present invention may further contain Si in the range of 0.1 to 0.6 wt%. The Si (silicon) component improves the moldability by improving the fluidity of the aluminum alloy. On the other hand, when the anodizing is performed, smut is generated on the surface, which makes it difficult to color and deteriorate the strength of the coating. In the aluminum alloy for die casting of the present invention, the Si content is preferably added in an amount of 0.6 wt% or less based on the total weight of the entire alloy. When the Si component exceeds 0.6% by weight, there arises a problem that the coloring property is deteriorated due to occurrence of stain.

Further, the aluminum alloy for die casting of the present invention may further contain Fe in the range of 0.5 to 1.5 wt%. The Fe component reduces the adhesion of the aluminum alloy for die casting to the mold and reduces the erosion of the mold, and is preferably added in the range of 0.5 to 1.5 wt% based on the total weight of the entire alloy. If the Fe component is less than 0.5% by weight based on the total weight of the entire alloy, there is a problem that the aluminum alloy is dislocated to the mold. On the other hand, when the Fe content exceeds 1.5% by weight, corrosion resistance and anodizing property of the aluminum alloy are lowered.

In addition, the aluminum alloy for die casting of the present invention may further contain Ni of 0.1 wt% or less. The Ni component serves to increase the toughness by refining the structure, and is preferably added in the range of 0.1 wt% or less based on the total weight of the entire alloy.

In addition, the aluminum alloy for die casting of the present invention may further contain 0.5 to 1% by weight of Mg. The Mg component facilitates corrosion resistance and anodic oxide film formation. Adding up to about 1% increases the strength. On the other hand, when the amount of Mg component increases, a phenomenon such as surface unevenness occurs after anodizing. Therefore, it is preferable to add Mg component in the range of 0.5-1.0 wt% based on the total weight of the entire alloy.

The aluminum alloy for die casting of the present invention contains not more than 0.5% by weight of Ti. The Ti component serves to refine the crystal grains in the alloy, and is preferably added in an amount of 0.5 wt% or less based on the total weight of the entire alloy. If it exceeds 0.5% by weight, the strength of the material is lowered.

The aluminum alloy for die casting of the present invention can be produced according to a general alloy manufacturing method. That is, the aluminum alloy ingot may be prepared by dissolving pure aluminum, injecting the mother alloy into the pure aluminum molten metal to dissolve the molten alloy, stirring the molten metal and subjecting the molten alloy to degassing, and then obtaining an aluminum alloy ingot.

The thus-prepared aluminum alloy for die casting of the present invention may have a tensile strength in the range of 180 to 250 MPa and an elongation of 5 to 10%.

The aluminum alloy for die casting not only makes it possible to realize uniform and beautiful colors without causing surface unevenness due to smearing of silicon during anodizing, but also can increase the adhesive strength of the film and increase the durability of the die casting product .

Next, the aluminum alloy is prepared and molded according to a conventional die casting process (S20). The target product may be a mobile terminal cover, a cover of a notebook computer, and the like.

Further, when the aluminum alloy has different composition and uses, the molded product can be prepared through a press working extrusion process or the like.

Next, the aluminum alloy molded product is anodized to form an anodized film (S30). The anodizing process may be according to conventional techniques. For example, a degreasing process for removing a fat adhered to the surface of a molded product, an etching process (chemical polishing or electrolytic polishing) for corroding the surface of the molded product, an anodic oxidation coating using sulfuric acid, phosphoric acid, Forming process. In this embodiment, the anodic oxide coating can be formed by dipping the molding in a sulfuric acid solution for about 20 to about 60 minutes.

Next, as shown in Fig. 2, a mask 20 is formed on the surface of the anodized molded product 10. Then, as shown in Fig. The mask 20 may be a coating formed by providing an eco-direct ink of solvent type on the surface of the anodized molded article 10 using an inkjet printer. Preferably, the mask has a thickness variation along the region, and may have a thickness of about 10 [mu] m to about 30 [mu] m.

3 is an enlarged cross-sectional view of the mask 20 shown in Fig. Referring to FIG. 3, the anodized molded article has pores 15 formed in the surface thereof, and the ink penetrates into the start 15. Therefore, depending on the thickness of the mask 20, a portion completely covered by the mask 20, a portion partially exposed by the ink penetrating the pores 15, and a portion completely exposed are divided.

Next, the molded product 10 on which the mask 20 is formed is etched to form a pattern. The etching may include a first etching step (S40) and a second etching step (S50).

The first etching step may be performed by applying an alkaline solution of caustic soda to the mask 20 so as to lessen the influence of ink components constituting the mask 20, Corrosion to give texture primarily. For example, the first etching step may be performed by dipping the molded product 10 into the alkali solution for about 30 seconds to about 3 minutes. As the dipping time becomes longer, the depth of the pattern becomes larger.

In the second etching step, an aluminum alloy is additionally removed by adding an acid solution containing phosphoric acid, sulfuric acid, and the like, and the mask 20 is removed to form a pattern having a softer profile, . For example, the second etching step may be performed by dipping the molded product 10 into the acid solution for about 5 seconds to about 30 seconds, and may be repeatedly performed depending on the application amount of the ink and the desired gloss.

As a result, the molded article 10 may have a protruding portion 17 pattern having a shape corresponding to the mask 20, as shown in Fig.

Next, the molded product having the pattern is anodized (S60). The anodic oxidation is performed to uniformly form the anodic oxide film to be removed in the process of forming the pattern, and to carry out the coloring step. The anodizing step may be the same as or similar to the anodizing step described above.

Before the formation of the anodic oxide coating, degreasing, chemical polishing, electrolytic polishing, or the like may be performed as described above.

Next, the molded article is colored (S70). The coloring step may be performed by providing the molded product 10 with a solvent-type eco-direct pigment ink. For example, the pigment ink may be printed on the molding using the same or similar printer as used for forming the mask. Accordingly, the design realized by the coloring may have various shapes, colors, colors, and the like.

The pigment inks may include various pigments such as red, blue, green, brown, yellow, pink, and gold depending on the desired coloring design. In another embodiment, the coloring may be performed using a dye ink.

Next, the colored molding is sealed (S80). The above-mentioned sealing process is for sealing the pores formed in the anodized film to smooth the surface, and to provide the weather resistance of the colored film and the corrosion resistance of the film. The above-mentioned sealing step may be performed by a general sealing method, a metallic sealing method, an organic sealing method, or a low-temperature sealing method.

For example, through the above embodiment, an aluminum alloy cover having a leather design excellent in texture and color, as shown in Fig. 5, can be manufactured.

According to the embodiment of the present invention described above, an aluminum alloy product having a pattern of a smooth profile and a uniform color design is manufactured through the formation of a mask using ink in an anodized molded product and etching using a thickness gradient can do.

In addition, various designs can be realized by forming a mask and coloring using a printer.

The present invention can be used for improving the appearance of various aluminum alloy products and for covering electronic products.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the present invention as defined by the following claims. You will understand.

Claims (12)

Anodizing the aluminum alloy molding;
Forming a mask on a surface of the anodized aluminum alloy molding;
Etching the aluminum alloy mold having the mask formed thereon to form a pattern on a surface thereof;
Anodizing the aluminum alloy molding having the pattern; And
And coloring the anodized aluminum alloy molding. The aluminum alloy molded article according to claim 1, wherein said aluminum alloy molded article comprises 1.0 to 5.0% by weight of Mn, 0.5 to 1.5% by weight of Zn, 1.0 to 2.0% by weight of Zr, 0.5 to 1.5% Method of surface treatment of aluminum alloy. The method according to claim 1, wherein the mask is formed by providing a solvent-type eco-direct ink on the surface of the aluminum alloy molding using a printer. The method for surface treatment of an aluminum alloy according to claim 1, wherein the mask has a thickness of 10 탆 to 30 탆. 2. The method of claim 1, wherein etching the aluminum alloy mold comprises:
A first etching step of applying an alkali solution; And
And a second etching step of applying an acid solution to the surface of the aluminum alloy. 6. The method according to claim 5, wherein the acid solution comprises phosphoric acid or sulfuric acid. The method of claim 1, wherein the step of coloring the anodized aluminum alloy moldings comprises:
A method of treating a surface of an aluminum alloy, comprising the step of providing ink containing a pigment using a printer. The method according to claim 1, further comprising a step of sealing the colored aluminum alloy molding. The method for surface treatment of an aluminum alloy according to claim 1, wherein the aluminum alloy molding is a press-processed product or an extrusion-processed product. An aluminum alloy cover for electronic appliances, formed from an aluminum alloy, having an anodized coating and having a colored pattern formed by etching on the surface. 11. The electronic device according to claim 10, wherein the aluminum alloy comprises 1.0 to 5.0% by weight of Mn, 0.5 to 1.5% by weight of Zn, 1.0 to 2.0% by weight of Zr, 0.5 to 1.5% Aluminum alloy cover for. The aluminum alloy cover for an electronic product according to claim 10, wherein the aluminum alloy is anodized and colored by press working and extrusion.

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