TWI498458B - Aluminum alloy surface treatment method and the method made of aluminum alloy - Google Patents

Description

Aluminum alloy surface treatment method and aluminum alloy prepared by the method

The invention relates to an aluminum alloy surface treatment method and an aluminum alloy prepared by the method, in particular to forming a porous oxide film containing polyaniline on the surface of the aluminum alloy, so as to reduce the pollution of the aluminum alloy stored in a general environment (such as water and gas). And the degree of oxidation, that is, the porous oxide film containing polyaniline can delay the rate of oxide formation on the surface of the aluminum alloy, and can avoid the surface roughness of the aluminum alloy due to the formation of oxides, thereby affecting the relationship between the aluminum alloy and the plastic The bonding strength and the porous oxide film containing polyaniline also help to improve the bonding strength between the aluminum alloy and the plastic.

According to the press, there are many metal products on the market that are combined with a plastic layer in the outer casing, and the plastic layer is used as a heat-insulating, anti-collision, anti-scratch protection, such as the outer casing component of the 3C product.

The combination of conventional aluminum or aluminum alloy and plastic is directly processed with plastic injection by subjecting aluminum or aluminum alloy to some special surface etching treatment (for example, chemical etching or electrochemical etching). Combined, therefore, the surface treatment of aluminum or aluminum alloy is an important treatment process for aluminum.

The surface treatment of aluminum or aluminum alloy mainly includes anodizing or chemical conversion processes, among which the prior art of anodizing aluminum or aluminum alloy is as disclosed in the Republic of China Invention Patent Publication No. 201325905 "Aluminum or Aluminum Alloy Surface Treatment Method" And the product of the article, discloses an aluminum or aluminum alloy surface treatment method and article, the product comprising an aluminum or aluminum alloy substrate, an anodized film and an electroplated layer sequentially formed on the aluminum or aluminum alloy substrate, The anodized film includes a barrier layer and a porous layer sequentially formed on a surface of the aluminum or aluminum alloy substrate, the anodized film is further formed with a plurality of second oxidation holes, and the second oxidation holes penetrate the barrier a layer and a porous layer; and a prior art of chemical conversion of aluminum or aluminum alloy, such as the patent of the Republic of China Invention Patent Publication No. 391988 "Improved Method for Surface Treatment of Aluminum Alloys", discloses an improved method for surface treatment of aluminum alloy, A composite film of a chromate and a water-based PU (polyurethane) is formed on the surface of the aluminum alloy.

The above-mentioned conventional disadvantages are as follows:

1. The former "improved method for surface treatment of aluminum alloy", in which the chemical conversion liquid used in the chromate chemical conversion surface treatment step contains chromate (such as potassium dichromate K ₂ Cr ₂ O ₇ ), Therefore, the chemical conversion process of aluminum alloys will have an impact on the environment caused by heavy metal pollution.

2. The previous case "Aluminum or aluminum alloy surface treatment method and product", through the anodization, forms a porous anodized film on the surface of aluminum or aluminum alloy, due to a large number of micro The area inside the hole increases the bonding strength between the surface of the aluminum or aluminum alloy and the plastic, but the anodized film is not sealed, so that the aluminum or aluminum alloy exposed to the environment increases relative to the effective surface area. The degree of environmental pollution (such as moisture in the air) is also greatly increased, resulting in lower yields of subsequent surface treatment processes (such as surface coating, plastic coating and plastic injection molding).

The aluminum alloy has the advantages of light weight, easy processing, and low price, and is often used in a shell assembly such as a 3C product. Therefore, the present invention is mainly directed to an aluminum alloy surface treatment method and an aluminum alloy produced by the method. A porous oxide film containing polyaniline is formed on the surface of the aluminum alloy to reduce the degree of oxidation of the aluminum alloy stored in a general environment due to contamination (such as moisture), that is, the porous oxide film containing polyaniline can delay the surface formation of the aluminum alloy. The speed of the oxide can prevent the surface roughness of the aluminum alloy from being lowered due to the formation of oxides, thereby affecting the bonding strength between the aluminum alloy and the plastic, and the porous oxide film containing polyaniline also contributes to the improvement of the aluminum alloy and the plastic. The strength of the bond.

The aluminum alloy surface treatment method of the present invention comprises the following steps: A. placing an aluminum alloy in an electrolyte, the electrolyte comprising an acidic solution for anodizing the aluminum alloy, and monoaniline and One with benzene The amine reacts to form a mixed solution of the polyaniline organic acid; B. the aluminum alloy is anodized in the electrolyte, and a porous oxide film having a plurality of oxide pores and containing polyaniline is formed on the surface of the aluminum alloy. The aluminum alloy is taken out from the electrolyte.

The acidic solution is an aqueous solution of any one of sulfuric acid, chromic acid, phosphoric acid or oxalic acid.

Wherein, the organic acid is benzenesulfonic acid, p-Toluenesulfonic acid, N-Butyl-benzenesulfonamide, dodecylbenzenesulfonic acid ( Any of Dodecyl benzenesulfonic acid) or camphorsulfonic acid.

Wherein, the acidic solution of the electrolyte is at a volume concentration of 100 ml to 250 ml of an aqueous sulfuric acid solution per liter, and 10 to 30 g of aniline per liter and 30 to 70 g of liter per liter are added to the aqueous sulfuric acid solution. An alkylbenzene sulfonic acid; the aluminum alloy is placed in the electrolyte to be anodized for 5 minutes to 60 minutes, and the current density through the aqueous sulfuric acid solution is 0.005 amps to 0.045 amps per square centimeter of the aluminum alloy.

In the aluminum alloy produced by the method for treating an aluminum alloy according to the present invention, a porous oxide film containing polyaniline is provided on the aluminum alloy, and the polyaniline-containing porous oxide film has a plurality of oxide pores.

The film thickness of the polyaniline-containing porous oxide film is from 2 μm to 18 μm.

Wherein, the opening aperture of the oxidation hole is between 10 nm and 200 nm.

The effect of the invention is:

1. The invention effectively reduces the contamination of the aluminum alloy stored in a general environment The degree of oxidation by dyeing (such as water vapor), that is, the porous oxide film containing polyaniline can delay the rate of oxide formation on the surface of the aluminum alloy, and can avoid the surface roughness of the aluminum alloy due to the formation of oxide. In turn, the bonding strength between the aluminum alloy and the plastic is affected, so that the yield of subsequent surface treatment processes (such as surface coating, overmolding, plastic injection molding, etc.) can be improved.

2. The polyaniline-containing porous oxide film on the surface of the aluminum alloy of the present invention contributes to enhancing the bonding strength between the aluminum alloy and the plastic.

3. The invention effectively extends the service life of the aluminum alloy composite substrate formed by the aluminum alloy and the plastic.

4. The surface treatment method of the aluminum alloy of the invention is simple, and the manufacturing process is free from heavy metal pollution.

(1)‧‧‧Aluminium alloy

(2) ‧‧‧Porous oxide film containing polyaniline

(21)‧‧‧ Polyaniline

(3) ‧ ‧ oxidized pores

(4) ‧‧‧Plastic layer

(d) ‧ ‧ film thickness

(t) ‧‧‧Open aperture

[First Figure] is a flow chart of a preferred embodiment of the present invention.

[Second figure] is a schematic view showing the structure of the polyaniline-containing porous oxide film formed on the surface of the aluminum alloy in the preferred embodiment of the present invention.

[Third Figure] is an electron micrograph of the surface of the aluminum alloy in the preferred embodiment of the present invention.

[Fourth figure] is an electron micrograph of the surface of the aluminum alloy in the preferred embodiment of the present invention.

[Fifth Figure] is a graph showing the relationship between the film thickness of the polyaniline-containing porous oxide film and the time of the anodizing treatment in the preferred embodiment of the present invention.

[Sixth] is a schematic view showing the structure of forming a plastic layer on the porous oxide film containing polyaniline in the preferred embodiment of the present invention.

[Seventh Image] is an infrared spectrum diagram of a preferred embodiment of the present invention.

In combination with the above technical features, the main effects of the aluminum alloy surface treatment method and the aluminum alloy produced by the method of the present invention will be clearly shown in the following examples.

First, referring to the first and second figures, the aluminum alloy surface treatment method of the present invention and the aluminum alloy produced by the method are preferred embodiments of the present embodiment. The aluminum alloy uses 6061 aluminum alloy, and the aluminum alloy surface treatment method of the embodiment includes the following steps:

A1. Surface degreasing cleaning of an aluminum alloy (1) with a degreaser using sodium hydroxide at a concentration of 6 percent by weight, sodium nitrate at a concentration of 2 percent by weight, The aluminum alloy (1) is immersed in the degreaser for degreasing at a concentration of 1% by weight of ethanolamine and an aqueous solution of 0.7% by weight of sodium persulfate, and the temperature is Celsius. The aluminum alloy (1) is degreased and cleaned at 70 degrees for 5 minutes, and the aluminum alloy (1) is subjected to secondary water washing after degreasing. The temperature of the first water washing is 50 degrees Celsius, the water washing time is 1 minute, and the second water washing is performed. The temperature was 25 ° C and the water washing time was 1 minute to surely clean the surface of the aluminum alloy (1).

A2. The oxide scale and the insoluble matter on the surface of the aluminum alloy (1) are removed by a deoxidizing agent, which comprises 550 ml of a concentration of 5% by weight of nitric acid and 60 g per liter. An aqueous solution of ammonium hydrogen fluoride, the aluminum alloy (1) is immersed in the deoxidizing agent for deoxidation, and the aluminum alloy (1) is subjected to secondary water washing after deoxidation, and the temperature of the first water washing is 50 degrees Celsius, and the water is washed. The time was 1 minute, the temperature of the second washing was 25 degrees Celsius, and the washing time was 1 minute to surely clean the surface of the aluminum alloy (1).

A3. The aluminum alloy (1) is placed in an electrolyte, the electrolyte comprising an acidic solution for anodizing the aluminum alloy, and an aniline and a a mixed solution of an organic acid capable of reacting with aniline to form a polyaniline; in the present embodiment, the acidic solution is a volumetric concentration of 100 ml to 250 ml of an aqueous sulfuric acid solution per liter, and 10 g per liter is added to the aqueous sulfuric acid solution. 30 grams of aniline and 30 grams to 70 grams of dodecylbenzene sulfonic acid per liter.

B. While the foregoing electrolyte is fully uniformly mixed, a DC power supply is connected, the voltage is 14 volts to 24 volts, and the current density through the electrolyte is 0.005 amps per square centimeter of the aluminum alloy (1). 0.045 amps, the reaction temperature is 15 degrees Celsius to 25 degrees Celsius, the voltage in this embodiment is 20 volts, the current density through the aqueous sulfuric acid solution is 0.015 amps per square centimeter of the aluminum alloy (1), and the reaction temperature is 22 degrees Celsius Degree, the aluminum alloy (1) immersed in the electrolyte is anodized for 5 minutes to 60 minutes, and a plurality of oxidation holes (3) are formed on the surface of the aluminum alloy (1) and contain polyaniline ( After the porous oxide film (2) of 21), the aluminum alloy (1) is taken out from the electrolytic solution; wherein the film thickness (d) of the porous oxide film (2) containing the polyaniline (21) is 2 Micron to 18 micrometers, in this embodiment, the aluminum alloy (1) is immersed in the electrolyte for anodizing for 30 minutes, and the film thickness (d) is formed on the surface of the aluminum alloy (1) from 11 micrometers to 12 micrometers. The porous oxide film (2) (please refer to the third figure), which contains polyaniline (21) The film thickness (d) of the porous oxide film (2) is related to the time of the anodizing treatment, please refer to the time shown in the fifth figure, along with the anodizing treatment time. The thicker, the thicker the film thickness (d) of the porous oxide film (2) containing polyaniline (21), and the oxidation pores on the porous oxide film (2) containing polyaniline (21) (3) The opening aperture (t) is between 10 nm and 200 nm. In the present embodiment, the opening aperture (t) of the oxidation hole (3) is between 10 nm and 80 nm (please cooperate) See the fourth picture).

C. Washing procedure: The anodized aluminum alloy (1) is washed more than once, and washed in the last water washing process with ultrasonic vibration for 1 minute to 2 minutes. The temperature of the washing is 15 degrees Celsius. The electrolytic solution adhered to the surface of the aluminum alloy (1) after the completion of the reaction was washed off to 35 ° C. In the present embodiment, the water was washed three times with a water washing temperature of 25 ° C and a water washing time of 1 minute.

D. Drying procedure: the water-washed aluminum alloy (1) is baked at a temperature of from 60 degrees Celsius to 80 degrees Celsius, and the baking time is between 15 minutes and 40 minutes, thereby reliably removing the aluminum alloy ( 1) The water vapor remaining on the top is baked at a temperature of 70 ° C in the present embodiment, and the baking time is 20 minutes.

After performing the foregoing steps, the porous oxide film (2) containing the polyaniline (21) is formed on the surface of the aluminum alloy (1) by using the porous oxide film (2) containing polyaniline (21). The oxidation pores (3) can make plastics (for example: polyvinyl chloride (PVC), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS) Propylene-butadiene-styrene copolymer (ABS), polycarbonate (PC), polyethylene (PE), polyetheretherketone (PEEK), polyacetal resin (POM), polypropylene resin (PP), polytetrafluoroethylene (PTFE), polyamine Methyl ester (PU), unsaturated polyester (UP), polyphenylene sulfide (PPS) and high glass fiber are tightly bonded to the porous oxide film (2) containing polyaniline (21). Bonding, forming a plastic layer (4) on the porous oxide film (2) containing polyaniline (21), as shown in Fig. 6; and polyaniline on the surface of the porous oxide film (2) 21) facilitating adhesion of the plastic layer (4) to the porous oxide film (2) containing polyaniline (21), thereby improving the bonding strength between the aluminum alloy (1) and the plastic layer (4). The aluminum alloy (1) and the plastic layer (4) are not easily separated from each other by external force, so the plastic layer (4) can be firmly bonded to the aluminum alloy (1); on the other hand, the aluminum alloy (1) The porous oxide film (2) containing the polyaniline (21) is formed thereon so that the aluminum alloy (1) which is not subjected to injection molding, plastic coating, coating, or the like can be stored in a general environment to be reduced in the environment. Pollution (such as moisture in the air) reduces the degree of oxidation, That is, the porous oxide film (2) containing polyaniline (21) can delay the rate of oxide formation on the surface of the aluminum alloy (1), and can avoid the surface roughness of the aluminum alloy (1) due to the formation of oxide. Decreasing, and thus affecting the bonding strength between the aluminum alloy (1) and the plastic, thereby improving the yield of the subsequent surface treatment process; comprehensively extending the aforementioned advantages, effectively extending the aluminum alloy composite substrate formed by the aluminum alloy (1) and the plastic The period of use.

Referring to FIG. 7 again, it is the infrared spectrum of the present embodiment. In the figure, the absorption peaks with wavenumbers of 1645 cm ^-1 and 1456 cm ^-1 correspond to the vibration absorption peaks of the benzene ring skeleton (υ _{C= C} ), the absorption peak with a wave number of 1502 cm ^-1 corresponds to the characteristic absorption peak of benzene structure (υ _NBN ), and the absorption peaks with wavenumbers of 1380 cm ^-1 and 1312 cm ^-1 respectively correspond to carbon-hydrogen bond (CH) bending Vibration and carbon-nitrogen bond (CN) stretching vibration absorption peak, the absorption peak with a wave number of 1143 cm ^-1 corresponds to the 醌-type structure absorption peak (υ _NQN ), where Q represents an anthracene ring and B represents a benzene ring. From the analysis results of the infrared spectrum, it was confirmed that the porous oxide film contained polyaniline.

In view of the foregoing description of the embodiments, the operation and the use of the present invention and the effects of the present invention are fully understood, but the above described embodiments are merely preferred embodiments of the present invention, and the invention may not be limited thereto. Included within the scope of the present invention are the scope of the present invention.

Claims (5)

An aluminum alloy surface treatment method comprises the following steps: A. placing an aluminum alloy into an electrolyte, the electrolyte comprising an acidic solution for anodizing the aluminum alloy, and an aniline and a A mixed solution of an organic acid of polyaniline formed by reacting with aniline, the acidic solution of the electrolyte is a volumetric concentration of 100 ml to 250 ml of aqueous sulfuric acid per liter, and 10 to 30 g of aniline per liter is added to the aqueous sulfuric acid solution. And 30 grams to 70 grams of dodecylbenzenesulfonic acid per liter; B. anodizing the aluminum alloy in the electrolyte, and forming a plurality of oxide pores on the surface of the aluminum alloy and containing polyaniline After the porous oxide film, the aluminum alloy is taken out from the electrolytic solution, and a plastic layer is formed on the porous oxide film containing polyaniline. The method for surface treatment of an aluminum alloy according to claim 1, wherein the acidic solution is an aqueous solution of any one of sulfuric acid, chromic acid, phosphoric acid or oxalic acid. The method for surface treatment of an aluminum alloy according to claim 1, wherein the organic acid is benzenesulfonic acid, p-toluenesulfonic acid, N-butylbenzenesulfonate, dodecylbenzenesulfonic acid or camphor Any of the sulfonic acids. The method for surface treatment of an aluminum alloy according to claim 1, wherein the aluminum alloy is placed in the electrolyte to be anodized for 5 minutes to 60 minutes, and the current density of the aqueous solution of sulfuric acid is the aluminum. The alloy passes from 0.005 amps to 0.045 amps per square centimeter. An aluminum alloy produced by the surface treatment method for an aluminum alloy according to any one of claims 1 to 4, wherein the aluminum alloy has a porous oxide film containing polyaniline containing polyaniline The porous oxide film has a film thickness of 2 micrometers to 18 micrometers, but does not include 10 micrometers to 18 micrometers. The polyaniline-containing porous oxide film has a plurality of oxide pores, and the pore diameter of the pores is 10 nanometers. Rice is between 200 nm, but does not include 10 nm to 20 nm.