KR101169256B1 - Power supply appartus for anodizing, anodizing method and anodized film - Google Patents

Abstract

A rectifier modulator capable of rectifying an AC voltage input from an AC power source into one or more DC pulse waves, and modulating and outputting a period or amplitude of one or more DC pulse waves, and an AC pulse wave modulating the period or amplitude of AC voltage. AC modulator capable of outputting and a pulse wave synthesizing unit for synthesizing two or more of one or more DC pulse wave and AC pulse wave and outputting the mixed pulse wave, wherein the mixed pulse wave has a peak voltage at the start of the unit pulse. An appearing power supply for anodizing is disclosed.

Description

Power supply device for anodizing, anodizing and anodizing film {Power supply appartus for anodizing, anodizing method and anodized film}

The present invention relates to an anodizing method for forming an oxide film on the surface by an electrochemical method in order to improve the corrosion resistance or abrasion resistance of nonferrous metal materials such as aluminum alloy, etc. It relates to a power supply for anodization providing a mixed pulse wave, anodization using the same and anodization film formed through the same.

In general, nonferrous metals such as aluminum (Al), magnesium (Mg), and titanium (Ti) form a naturally thin oxide layer by high reactivity with moisture in the air. However, such a natural oxide layer has a very thin thickness or a dense structure, making it difficult to serve as a protective layer to protect the nonferrous metal material from abrasion and corrosive environments. Therefore, the oxide layer is formed on the surface by various methods for the purpose of protecting the material by improving the surface properties of the nonferrous metal material. The oxide layer may be formed by a chemical method or an electrochemical method. In aluminum, which is a representative nonferrous metal material, a method of chemically treating the surface is a chromate treatment or boehmite treatment. This method is a method of forming an oxide layer on the aluminum surface by a chemical reaction on the aluminum surface without applying electricity to the aluminum. However, such a chemical surface treatment method has a disadvantage that its application range is limited because the oxide layer film is thin or wear resistance is poor. In comparison, anodization, an electrochemical method, is a method of forming an anodization film electrochemically by applying electricity to an aluminum surface using a sulfuric acid solution as an electrolyte. Anodic oxide film formed by the above anodic oxidation method is excellent in mechanical properties, electrical and chemical properties, there are a wide variety of applications such as construction terminal, mechanical field, automotive industry, aviation industry, portable terminal.

In the conventional anodization, DC power is supplied between electrodes to electrochemically oxidize the surface of a base material. That is, the surface of the base material is electrochemically oxidized by supplying a DC power supply in an electrolytic cell containing an electrolyte using the base material to be oxidized as the anode.

 However, in the conventional anodization, an oxide layer is formed due to the reaction between the metal surface and the electrolyte, and metal dissolution occurs. As the thickness of the formed oxide layer increases, the density of the oxide layer decreases and mechanical properties deteriorate. It is difficult to grow more than a certain limit. In addition, when a specific oxide layer is electrodeposited at the interface between the base metal layer and the oxide layer before the anodic oxidation process, the adhesion is markedly deteriorated, so that a phenomenon in which the oxide layer is peeled from the aluminum base material may appear.

In order to solve the above problems, the present invention provides a power supply and anodizing method for anodizing which can form an anodic oxide film which is significantly increased in thickness compared to the conventional anodizing film and has improved mechanical, electrical and chemical properties. An object of the present invention is to provide an anodization film formed using the same.

The first aspect of the present invention for achieving the above object of the present invention is a voltage supply device for supplying a voltage between the anode and the cathode for anodization, it is possible to rectify the AC voltage input from the AC power source into a DC pulse wave, A rectifier modulator capable of modulating and outputting the period or amplitude of the DC pulse wave, and an AC modulator capable of outputting an alternating pulse pulse of modulating the period or amplitude of an AC voltage input from the AC power source and the rectifier modulator. A pulse wave synthesis unit which receives any one or more of a DC pulse wave from the AC pulse wave or an AC pulse wave from the AC modulator and outputs a DC / DC mixed pulse wave or a DC / AC mixed pulse wave to be applied between the anode and the cathode. And providing a control unit for controlling the operation of the rectifier modulation unit and the AC modulation unit. .

In this case, the power supply device may further include a switch between the rectifier modulator and the AC power source, or between the AC modulator and the AC power source, or between the rectifier modulator and the pulse wave synthesizing part or the AC modulator and the pulse. A switch may be further provided between the synthesis units, and the switch may be controlled by the controller.

In addition, the rectifier modulation unit may include two or more stops each independently operated.

On the other hand, the second aspect for achieving the object of the present invention is an anodizing method for forming an anodized film on the surface of the aluminum member in the electrolyte solution, DC / AC mixed pulse wave synthesized DC and AC pulse wave between the positive electrode and the negative electrode Anodization is performed by supplying and the DC / AC mixed pulse wave provides an anodization method characterized in that a peak voltage appears at a starting point of a unit pulse.

In this case, the DC / AC mixed pulse wave may include a curvature component in which the pulse waveform is convex upward when falling from the peak voltage with time.

In addition, a negative voltage may be applied to the DC / AC mixed pulse wave between time intervals in which a positive voltage is applied.

In addition, the DC pulse wave may be a DC / DC mixed pulse pile synthesized with two or more DC pulse waves different from each other with a positive voltage and a time interval for applying the positive voltage.

In addition, in the DC / AC mixed pulse wave, the maximum voltage or the average voltage of a unit pulse may change according to a pulse progress time, and the change according to the pulse progress time may be a sine wave shape or a step shape.

Meanwhile, the DC / AC mixed pulse wave as described above includes a DC / AC mixed pulse wave in which at least one of a section in which a positive voltage is applied and a section in which a positive voltage is not applied are changed according to a pulse propagation time.

On the other hand, the third aspect for achieving the object of the present invention is an anodized film formed on the surface of the aluminum member using a DC / AC mixed pulse wave synthesized by a DC pulse wave and an AC pulse wave, the anodic oxide film has a thickness of up to 300u It is to provide an anodization film having a diameter of 50㎛, the cell of the anodization film ranges from 50nm to 200nm.

According to an aspect of the present invention, a power supply for anodizing may rectify an AC voltage input from an AC power source into one or more DC pulse waves, and modulate and output a period or amplitude of the one or more DC pulse waves. Rectifier modulation unit; An AC modulator capable of outputting an AC pulse wave modulating the period or amplitude of the AC voltage; And a pulse wave synthesis unit configured to synthesize two or more of the at least one DC pulse wave and the AC pulse wave and output the mixed pulse wave, wherein the mixed pulse wave exhibits a peak voltage at a start point of a unit pulse.

The anodization method according to another aspect of the present invention is an anodization method for forming an anodization film on the surface of an aluminum-containing member in an electrolyte solution, wherein a mixed pulse wave obtained by synthesizing two or more of at least one DC and AC pulse waves between an anode and a cathode Anodization is performed, and the mixed pulse wave exhibits a peak voltage at the start of the unit pulse.

In this case, the mixed pulse wave may include a curvature component in which the pulse waveform is convex upward when falling from the peak voltage with time.

In this case, a negative voltage may be applied to the mixed pulse wave between sections in which a positive voltage is applied.

In this case, the mixed pulse wave may include two or more DC pulse waves different from each other when a positive voltage is applied.

In this case, the mixed pulse wave may change the maximum voltage or the average voltage of the unit pulse according to the pulse progress time.

In this case, the mixed pulse wave may have a sine wave shape in which the maximum voltage or the average voltage of the unit pulses depends on the pulse progress time.

At this time, the change according to the pulse progress time of the maximum voltage or the average voltage of the unit pulse, the step of stepping up from the initial voltage to a predetermined first voltage, the step of maintaining a predetermined time from the first voltage, the first voltage Stepping up to a high second voltage, and maintaining a predetermined time at the second voltage.

At this time, the mixed pulse wave may be changed according to the pulse progress time any one or more of the interval in which the positive voltage is applied and the interval in which the positive voltage is not applied.

According to another aspect of the present invention, an aluminum-containing member is an aluminum-containing member including an anodized film formed using a mixed pulse wave synthesized from at least one DC pulse wave and an AC pulse wave, wherein the anodized film has a thickness of 20%. It is more than 300 micrometers and it is 300 micrometers or less.

When the power supply device according to the present invention is used, various pulse waves such as DC / DC mixed pulse wave and direct / AC mixed pulse wave as well as DC pulse wave may be formed and supplied to the electrode for anodizing.

In addition, the anodization film formed by the anodic oxidation method according to the present invention may be formed in a state having a uniform film structure with a thickness thicker than the film thickness generally formed in the prior art.

Due to the superior film structure, the anodic oxide film of the present invention exhibits excellent properties in mechanical properties such as hardness, abrasion resistance, flexural strength, corrosion resistance and insulation, compared to the conventional anodized film.

1 shows an anodization apparatus according to the present invention.
Figure 2 shows another power supply for anodizing the present invention.
3A to 3C show a first stage constant load pulse wave, a first stage constant load variable frequency pulse wave, and a first stage variable load variable frequency pulse wave according to the present invention, respectively.
Figure 4 shows a two-stage constant load pulse wave according to the present invention.
5A and 5B show a single stage constant load DC / AC mixed pulse wave and a two stage constant load DC / AC mixed pulse wave according to the present invention, respectively.
6A and 6B illustrate a 1-stage variable load variable frequency DC / AC mixed pulse wave and a 2-stage variable load variable frequency DC / AC mixed pulse wave according to the present invention, respectively.
7 shows a DC / AC mixed pulse wave in which the maximum voltage in the pulse shows a sine wave shape according to the pulse propagation time.
8 is a photograph of the cross section of the anodization film formed by the anodization method of the present invention with an electron microscope.
9 is a photograph observing the structure of the anodization film formed by the anodization method of the present invention with an electron microscope.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the present invention. In addition, in describing the present invention, when it is determined that the detailed description of the related known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted.

A schematic diagram of an apparatus for forming an anodization film on the surface of an aluminum member according to the invention is shown in FIG. The anodic oxidation device comprises a positive electrode 104 and a negative electrode 106 immersed in the electrolyte 100 and the electrolyte 102 filled with the electrolyte 102, and a power supply 108 for supplying power between the two electrodes. Equipped.

In this case, the anode uses aluminum or an aluminum alloy (hereinafter referred to as aluminum) in which an anodization film (ie, an aluminum oxide film) is formed.

In addition, the power supply 108 is a positive electrode by applying a DC / AC mixed pulse wave formed by synthesizing a normal DC voltage or a DC pulse wave or a DC pulse wave and an AC pulse wave as a pulse type DC voltage between the anode and the cathode. An oxide film can be formed. The configuration of one embodiment of a power supply device used for such anodization is shown in FIG.

As shown in FIG. 2, the power supply apparatus according to the present invention includes a rectifier modulator 220, an AC modulator 230, a pulse wave combiner 240, and a controller 250.

The rectifier modulator 220 may rectify an AC voltage input from the AC power source 210 to form a DC pulse wave, and modulate and output a period or amplitude (ie, a voltage value) of the DC pulse wave. In this case, the rectifier modulation unit 220 may be composed of one stop value or may be composed of two or more stop values that are independently operated. 2 illustrates a case in which the rectifier modulator 220 includes two stop values of the first stop value 222 and the second stop value 224.

The AC modulator 230 may output an AC pulse wave modulated with a period or amplitude of an AC voltage input from an AC power source.

The pulse wave synthesizing unit 240 outputs a DC / DC mixed pulse wave by synthesizing each DC pulse wave that is modulated and output from one or more stops constituting the rectifying modulator 220, or outputs the DC / DC mixed pulse wave. Synthesizing an AC pulse wave output from the 230 to output a DC / AC mixed pulse wave. For example, as shown in FIG. 2, when the rectifying modulator 220 includes a first stop 222 and a second stop 224, the first stop 222 and the second stop wit ( Each of the first DC pulse wave and the second DC pulse wave modulated at different periods and amplitudes after rectifying from AC to DC at 224 and the AC pulse wave modulated and output from the AC modulator 230 are pulse wave synthesis units. Input to 240 can be synthesized.

The controller 250 is connected to the rectifier modulator 220 and the AC modulator 230 to control the operation of the rectifier modulator 220 and the AC modulator 230 to control the characteristics of the pulse wave output therefrom. I can regulate it.

In this case, a switch may be further provided between the rectifier modulator 220 and the AC power source 210 or between the AC modulator 230 and the AC power source 210, and the controller 250 may turn on / off the switch. You can perform more control functions. By controlling such a switch, it is possible to control the output of the DC pulse wave and the AC pulse wave to the pulse wave combining unit 240. For example, as shown in FIG. 2, a first switch 260a and a second switch between the first stop 222, the second stop 224, and the AC modulator 230 and the AC power supply 210, respectively. 260b and 3rd switch 260c are arrange | positioned and controlled, and the shape of the pulse output to the pulse wave combining part 240 can be controlled. If only the first switch 260a is on and the remaining switches are off, one DC pulse wave is supplied to both electrodes through the pulse wave combining unit 240. However, if, for example, the first switch 260a and the second switch 260b are in an on state and the third switch 260c is in an off state, the pulse wave combiner 240 ), Two DC pulse waves are inputted and synthesized into DC / DC mixed pulse waves. In addition, when any one or more of the first switch 260a or the second switch 260b and the third switch 260c are turned on, the DC pulse wave and the AC pulse wave are input to the pulse wave combining unit 240, It is synthesized by the alternating mixed pulse wave and output.

Such a switch may be provided between the rectifier modulator 220 and the pulse wave combiner 240 or between the AC modulator 230 and the pulse wave combiner 240, and the action and effect thereof are as described above.

The shape of the synthesized pulse wave depends on the type of the input DC pulse wave or the AC pulse wave, and thus the control unit 250 outputs the DC pulse wave and the AC output from the rectifier modulator 220 and the AC modulator 230, respectively. By adjusting and controlling the shape of the pulse wave, the shape of the desired power supply can be determined by the pulse wave combining unit 240.

3A to 3C are single stage DC pulse waves that can be output from each of the first and second stop values 222 and 224, and the first stage constant load pulse wave, the first stage constant load variable frequency pulse wave, and the first stage variable. Load variable frequency pulse waves are shown respectively.

Such a DC pulse wave can exhibit the characteristics of a pulse wave using a work cycle. As shown in FIG. 3A, the work cycle may be expressed as the ratio of the time Ton at which the voltage for anodization (ie, a positive voltage) is applied and the time Toff at which the voltage for anodization is not applied. do.

Work cycle (%) = [Ton / (Ton + Toff)] × 100

The first-stage constant load pulse wave of FIG. 3A is a pulse wave in which a voltage applied for a ton interval has a constant pulse period and is kept constant as one value.

The characteristics of the pulse wave can be changed by changing the ratio of Ton and Toff in the work cycle of the constant load pulse wave.

 The first-stage constant load variable frequency pulse wave illustrated in FIG. 3b is the same as the one-stage constant load pulse wave in that the Ton section is kept constant within one cycle, that is, the unit pulse, but Toff while the pulse wave is in progress. The interval is changed.

The variable-stage variable frequency pulse wave of 1 stage is a pulse wave in which the Ton section is changed or the Ton section and the Toff section are changed together as the pulse wave progresses. The Ton and Toff sections are simultaneously changed in FIG. Pulse wave in the form is illustrated.

Meanwhile, a DC / DC mixed pulse wave formed by combining DC pulse waves output from the first stop value 222 and the second stop value 224, two-stage constant load pulse wave, two-stage constant load variable frequency pulse Spar and two-stage variable load variable frequency pulse waves can be synthesized.

4, a two-stage constant load pulse wave is shown. A two-stage constant load pulse wave has a constant unit cycle, and there are sections in which two different voltage values are maintained in the Ton section in the unit cycle. That is, the Ton section is composed of a section T _H in which a first voltage having a relatively high value is maintained and a section T _L in which a second voltage having a relatively low value is maintained, and T _H in all unit pulses. And T _L are all the same.

 The two-stage constant load pulse wave may be obtained by synthesizing a separate DC pulse wave from the first stop value 222 and the second stop value 224 in the pulse wave combining unit 240, respectively. For example, the first stop 222 outputs a first DC pulse wave having a relatively high output voltage and a relatively short Ton interval, and the second stop 224 has a relatively low output voltage and a Ton interval relatively. By outputting a long second DC pulse wave and synthesizing it in the pulse wave combining unit 240, a two-stage constant load pulse wave as shown in FIG.

It is also possible to form a two-stage constant load variable frequency pulse wave or a two-stage variable load variable frequency pulse wave on the same principle as described above. For example, in the case of a two-stage constant load variable frequency, the Ton of the first DC pulse wave and the second DC pulse wave output from the first stop value 222 and the second stop value 224 are kept constant. By matching the change of Toff according to the pulse progression in the same can be obtained a two-stage constant load variable frequency pulse, if the change in Ton can be obtained to obtain a two-stage variable load variable frequency pulse wave.

In addition, the power supply device of the present embodiment is a DC / AC mixed pulse wave synthesized with any one or more DC pulse wave of the first stop value 222 or the second stop value 224 outputted through the AC modulator 230 Can be formed and output. Fig. 5 shows an example of a DC / AC mixed pulse wave that can be output in this embodiment. The DC / AC mixed pulse wave is characterized by having a peak voltage by the AC pulse wave during the Ton period in the unit pulse. At this time, the peak voltage is the highest voltage value in the unit pulse, and the voltage value before or after it shows a relatively low voltage value.

5A is a one-stage DC / AC mixed pulse wave in which a single-stage constant load pulse wave is mixed with an AC pulse wave component whose voltage value changes with time, and a peak voltage is formed in a Ton section of a unit pulse. In this case, the peak voltage is preferably present at the start of the Ton section of the pulse. In this case, the pulse waveform may include a curvature component that is convex upward when falling from the peak voltage with time. In addition, as illustrated in FIG. 5, the DC / AC mixed pulse wave may have a pulse having a negative voltage value between the end point of the Ton section and the start point of the next Ton section (that is, the Toff section of FIG. 5). As described above, the AC modulator 230 may output an AC pulse wave modulating a period or amplitude of an AC voltage input from an AC power source. In addition, the shape of the voltage shown in FIG. 5A described above is that the AC pulse output through the AC modulator 230 is mixed with the first-stage constant load pulse wave of FIG. 3A, but the waveform shown in FIG. 5A is shown in FIG. 3A. It can be understood that subtracting the waveform of the first-stage constant load pulse wave leaves a waveform that resembles a sine wave of one cycle. At this time, it can be understood that in the Ton section of FIG. 5A, the voltage similar to the above sine wave has the largest value at the start point of the Ton section. That is, referring to the result of subtracting the waveform of FIG. 3A from the waveform of FIG. 5A, it can be understood that the AC pulse output through the AC modulator 230 has the largest value at the start point of the Ton section among the Ton sections.

In FIG. 5B, a two-stage direct current obtained by synthesizing an AC pulse wave output through the AC modulator 230 to a two-stage constant load pulse wave formed through the synthesis of the first stop value 222 and the second stop value 224. The alternating mixed pulse wave is shown. The formation principle of the two-stage DC / AC mixed pulse wave is also the same as that of the above-described one-stage DC / AC mixed pulse wave.

In addition, a constant load variable frequency DC / AC mixed pulse wave and a variable load variable frequency DC / AC mixed pulse wave obtained by synthesizing the AC pulse wave with the constant load variable frequency pulse wave and the variable load variable frequency pulse wave in the same principle as described above. Can be synthesized. 6A and 6B illustrate a single stage variable load variable frequency DC / AC mixed pulse wave and a two stage variable load variable frequency DC / AC mixed pulse wave, respectively.

The above DC / AC mixed pulse wave corresponds to the case where the maximum voltage or average voltage of each unit pulse (the average value of the maximum voltage and the minimum voltage in one cycle) is kept constant, but as the pulse wave progresses, It is also possible to form a form in which the voltage or the average voltage changes. As an example, FIG. 7 shows a two-stage variable load variable frequency DC / AC mixed pulse wave in which the maximum voltage of the unit pulse changes with the progress of the pulse wave, and the change in the maximum voltage indicates a sinusoidal wave form. An AC mixed pulse wave is shown.

In addition, in the process of anodizing, the maximum voltage or the average voltage may be changed stepwise according to the pulse wave propagation time. That is, anodization may be performed by continuously increasing the voltage from the initial voltage to the predetermined voltage and maintaining the voltage at a predetermined time when the pulse wave is applied between the anode and the cathode.

 As described above, various DC pulse waves, DC / DC mixed pulse waves, and DC / AC mixed pulse waves are possible, and by using these pulses, anodization film having more various physical properties can be formed. Anodization film formed on the surface of an aluminum member using a DC / AC mixed pulse wave synthesized through the voltage supply device of the present invention has an anode formed by using a conventional DC power supply or DC pulse wave. It is remarkably improved compared with the oxide film. In particular, as shown in the description of FIGS. 5A and 5A, when anodizing is performed using a DC / AC mixed pulse wave having a peak voltage at the start point of a pulse, the thickness reaches 300 μm. Anodization film having a very uniform structure could be formed, and such anodization film not only exhibited excellent performance not conventionally obtained in mechanical properties such as hardness and abrasion resistance, but also significantly increased in corrosion resistance.

Below, as an embodiment according to the present invention, the results of various characteristic tests of the anodic oxide film formed by the anodization method using a DC / AC mixed pulse wave is shown.

Example

Anodization was performed using a DC / AC mixed pulse wave synthesized using the power supply shown in FIG. 2, wherein the power supply was compactly configured in a drawer type. The first stop 222 and the second stop 224 of the power supply were built with a 600 kHz field effect transistor (FET) and a capacitor having a capacitance of 1500 uF and a rated voltage of 400V. At this time, each of the first and second stop values 222 and 224 has the same device as one set in consideration of the calorific value. The DC / AC mixed pulse wave used for anodizing is shown in FIG. 6B. This is a two-stage variable load variable frequency DC / AC mixed pulse wave. Each unit pulse has a convex curve up after the peak voltage appears at the start point, and the negative voltage value is between the end point of the Ton section and the start point of the next Ton section. This waveform is shown.

At this time, the base voltage (ie, the minimum voltage of the unit pulse) was -0.5V, the peak voltage was up to 40V, and the first and second voltages applied for the actual experiment were 10V and 5V, respectively. In addition, the period of the unit pulse was adjusted in the range from 10msec microwave to 10sec.

The concentration of the sulfuric acid solution for promoting the reaction was in the range of 3 to 10%, and the concentration of the sulfuric acid solution used in this experiment was 5 to 6%. In addition, wood vinegar can be added within the range of 3.0%, 1.0% was added in this experiment. In addition, the temperature of the electrolytic cell during the reaction time was maintained at -2 ℃.

Control of the DC / AC mixed pulse wave was performed as follows. After aluminum was used as an anodized object as an anode, the temperature was gradually increased from 0 V set as an initial voltage between the anode and the cathode to 5 V (first step) and maintained for about 5 minutes (second step). After raising the voltage to 10 V (step 3), the same voltage was maintained until the anodic oxide film having the required thickness was obtained (step 4). As the anodization process is carried out in these four stages, power consumption is lower than that of the conventional anodization process maintained at 15V to 40V, whereas the laminated anodization layer has a very dense structure and has high hardness, high wear resistance, and high corrosion resistance. Could get

According to this embodiment, the anodic oxide film was formed up to a thickness of 20 μm up to 300 μm, and all of the anodic oxide films formed in this way were composed of a cell structure having a uniform cross-sectional structure from the interface between aluminum and the anodized film to the surface of the anodized film. It was. The uniform structure in this thickness range was difficult to implement easily in the conventional anodization method. As an example, the result of observing the cross section of the anodization film having a thickness of 220 μm with an electron microscope is shown as an example. 9 shows the results of observing the microstructure of the anodization film. Anodization film according to an embodiment of the present invention exhibited a regular cell structure, wherein the diameter of the cell was in the range of 50nm to 100nm, so that the equipment (diameter / length) is up to 50 / 300,000 to 1/6000 Reached. 9 shows electron micrographs of portions having a diameter of about 50 nm and portions having a diameter of 80 nm. From this, it can be seen that when using the anodizing method of the present invention, an anodized film continuously grown can be obtained while maintaining a compact and uniform cell diameter. The microstructure characteristics of the anodization film according to the present invention are common to all thicknesses of the anodization film grown through the present embodiment. As described above, the anodization film having a uniform microstructure and a thickness of about 300 μm cannot be realized by the conventional anodization method. The anodization film according to the present invention has excellent mechanical and electrical properties due to its excellent microstructure. , Chemical properties.

Table 1 shows the results of Rockwell hardness (HRC, KS B 0806: 2000) and Vickers hardness (Hv) according to the aluminum type and the thickness of the anodization film formed according to the present embodiment. The hardness of SUS 316 stainless steel and titanium, which are used as structural materials in the field, is shown together. As can be seen from Table 1, the Al 6061 aluminum member without anodization showed significantly lower hardness than titanium and SUS 316 stainless steel, but the Rockwell hardness was increased when the anodization film was formed in the range of 20 μm to 60 μm. In the range of 57-59 (in the range of 636-675 for Vickers hardness), the results were excellent. This was a significantly higher value than titanium and SUS 316 stainless. In particular, when the anodization film was grown on an Al 5058 aluminum member, a very good hardness result with a Rockwell hardness of 70 (Vickers hardness 1030) was obtained.

Material and anodization thickness
HRC
Hv
Al 5058-25㎛ Lamination
70
1030
Al 6061-30㎛ Lamination
57
636
Al 6061-40㎛ Lamination
59
675
Al 6061-50㎛ Lamination
58
655
Al 6061-60㎛ Lamination
59
675
Al 6061-0㎛ Lamination
0
90
titanium
32
317
SUS 316
0
155

Table 2 shows the results of a three month salt spray test (KS D 9502: 2007) of the aluminum member on which the anodization film was formed according to the embodiment of the present invention. The test solution used for the test was 5 ± 1% sodium chloride (PH 6.8 ± 0.3), the test temperature was maintained at 35 ± 2 ° C, and the spraying amount was 2 ± 0.5ml / h / 80cm2. As shown in Table 2, it was found that all specimens did not undergo corrosion, such as swelling or rust, on the surface even in a saltwater environment of 3 months. From this, the aluminum member formed with the anodization film according to the present invention had corrosion resistance. Significantly improved.

Psalter
Anodization thickness
Test result
Psalm 1
46-48㎛
No swelling and rust
Psalm 2
93-95㎛
No swelling and rust
Psalm 3
155-165㎛
No swelling and rust

Table 3 lists the corrosion resistance data of metals currently used as corrosion resistant materials (Signature: Corrosion resistance tables: metals, plastics, nonmetallics, and rubbers, Author: Schweitzer, Philip A, Publisher: M. Dekker, Publication year: 1985 By indirectly comparing the aluminum member and the seawater corrosion resistance of the anodic oxide film according to the present invention according to the present invention, it can be seen that the products to which the present technology is applied have excellent seawater corrosion resistance.

Ti
SUS 316
Al 6061
Al (40 μm)
Al (70 μm)
Al (100 µm)
Corrosion resistance
(Seawater, mm / year)
0.05
0.50
0.70
0.00
0.00
0.00

Table 4 shows the wear resistance test results of the aluminum member on which the anodized film according to the present invention is formed. At this time, the abrasion resistance test was performed according to the abrasion strength test method of ASTM D 3884: 1992 of the United States. As can be seen from Table 4, in the case of the aluminum member with anodization film, the wear resistance was significantly superior to that of the aluminum member without the anodic oxide film. It can be seen that the wear resistance is more than doubled.

division
1 mg
2 mg
3 mg
Average
Al-0㎛ Coating
132
125
133
130.0
Al-20㎛ Coating
23
19
14
18.7
Al-30㎛ Coating
3
4
7
4.7
Al-40㎛ Coating
One
3
3
2.3

Table 5 shows the results of the thermal conductivity test of the aluminum member on which the anodization film according to the present invention is formed. At this time, the thermal conductivity test was performed by a laser (Laser Flash) method. The thermal conductivity coefficient k is 153.4 (W / mK) when there is no anodic oxide film, 150.7 (W / mK) when the thickness of the anodic oxide film is 20 µm, and 149.7 (W / mK) when the thickness is 40 µm. It can be seen that even if the lamination is made, the decrease in the thermal conductivity coefficient is only about 3% or less. It can be seen that these values show very high thermal conductivity coefficients compared to titanium and stainless steel, which are used for heat exchangers using seawater.

Ti
SUS 316
Al 6061
Al (40 μm)
Al (70 μm)
Al (100 µm)
Heat Transfer Coefficient (W / mK)
17
16
154
150
147
145

Table 6 shows the electrical insulation characteristics of the aluminum member on which the anodization film according to the present invention is formed. The electrical insulation test was carried out by installing a φ25mm electrode on the sample, applying a voltage of 2,000V for 1 minute, and then examining the dielectric breakdown. The test showed no breakdown under all test conditions. Therefore, it can be seen that the anodization film according to the present invention has excellent insulation.

division
result
Al-30㎛ coating
No breakdown
Al-40㎛ Coating
No breakdown

Table 7 shows the flexural strength characteristics of the aluminum member on which the anodized film according to the present invention is formed. The flexural strength test was performed according to the flexural strength method of ASTM D 790: 2003 of the United States. The tester was CRE type and the test speed was 2mm / min. As shown in Table 7, it can be seen that the aluminum member coated with the anodization film showed a better flexural strength value than the aluminum member without the anodization film.

division
result
No anodization
1140.1
Al-20㎛ Coating
1298.1

From the above series of test results, all of the aluminum members on which the anodization film was formed according to the present invention exhibited excellent surface properties, which could not be realized in the conventional anodization film formed by the conventional anodization method. From this, it can be seen that the present invention can form an anodized film with superior performance compared to the conventional anodized film.

The above-mentioned embodiments are illustrative rather than limiting on the present invention, and those skilled in the art can design many other embodiments without departing from the scope of the present invention as defined by the appended claims. In addition, it will be apparent that the technology of the present invention can be easily modified by those skilled in the art, such modified embodiments will be included in the technical spirit described in the claims of the present invention.

210: AC power supply 220: rectifier modulation unit
222: first stop 224: second stop
230: AC modulator 240: pulse wave synthesis unit
250: control unit 260a, 260b, 260c: switch

Claims (10)

As a power supply for anodization,
A rectification modulator capable of rectifying an AC voltage input from an AC power source into one or more DC pulse waves, and modulating and outputting a period or amplitude of the one or more DC pulse waves;
An AC modulator capable of outputting an AC pulse wave modulating the period or amplitude of the AC voltage; And
A pulse wave combining unit configured to synthesize the AC pulse wave and one or more DC pulse waves output from the rectifying modulator and output the mixed pulse wave;
Including;
Since the voltage of the AC pulse wave has the largest value at the start of the on section of the at least one DC pulse wave output from the rectifying modulator, in the unit pulse of the mixed pulse wave, the peak at the start point of the unit pulse is mixed. Characterized in that the voltage appeared,
Power supply for anodic oxidation. An anodizing method for forming an anodized film on the surface of an aluminum-containing member in an electrolyte solution,
Anodic oxidation is performed by applying a mixed pulse wave obtained by synthesizing an AC pulse wave and at least one DC pulse wave between an anode and a cathode.
The voltage of the AC pulse wave has the largest value at the start of the on period of the at least one DC pulse wave, so that the peak voltage appears at the start of the unit pulse in the unit pulse of the mixed pulse wave. Made,
Anodization. The method of claim 2,
And the mixed pulse wave comprises a curvature component whose pulse waveform is convex upward when falling from the peak voltage with time. The method of claim 2,
The mixed pulse wave is anodic oxidation method, a negative voltage is applied between the interval of the positive voltage is applied. The method of claim 2,
The mixed pulse wave includes a component of two or more DC pulse waves different from each other when a positive voltage is applied, and the synthesized pulse wave generated by synthesizing two or more different DC pulse waves, the ON of the synthesized pulse wave. Anodization with the largest value at the beginning of the (on) section. The method of claim 2,
The mixed pulse wave is anodizing method wherein the maximum voltage or the average voltage of the unit pulse is changed according to the pulse propagation time. The method according to claim 6,
The mixed pulse wave is anodizing method in which the maximum voltage or average voltage of a unit pulse exhibits a sine wave shape according to the pulse propagation time. The method according to claim 6,
The change according to the pulse progress time of the maximum voltage or the average voltage of the unit pulse,
Boosting the voltage from the initial voltage to the first predetermined voltage;
Maintaining a predetermined time at the first voltage;
Stepping up to a second voltage that is higher than the first voltage, and
Maintaining a predetermined time at the second voltage
Including, anodization. The method according to any one of claims 2 to 8,
In the mixed pulse wave, any one or more of a section in which a positive voltage is applied in a unit pulse and a section in which a positive voltage is not applied are changed according to a pulse propagation time. An aluminum-containing member comprising an anodized film formed using a mixed pulse wave in which an alternating pulse wave and at least one direct current pulse wave are synthesized.
Since the voltage of the AC pulse wave has the largest value at the start point of the on period of the at least one DC pulse wave, the peak voltage appears at the start point of the unit pulse in the unit pulse of the mixed pulse wave. ,
The anodizing film is an aluminum-containing member, having a thickness of 20 µm or more and 300 µm or less.

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