KR20140025001A - Steel sheet by coated aluminium-silicon alloy and method for manufacturing the same - Google Patents

Abstract

The present invention relates to aluminum-silicon coated steel and a manufacturing method for the same. The method for coating a steel plate using a sputtering process comprises the steps of forming a first coating layer at an oblique angle by coating aluminum-silicon alloy on the steel plate at the first oblique angle; and forming a second coating layer at an oblique angle by coating the aluminum-silicon alloy at the second oblique angle, which has the same size but a different direction as the first oblique angle. The first and second oblique angles are the angle between the vertical elements of a target and a test piece.

Description

Aluminum-silicon coated steel sheet and manufacturing method thereof {STEEL SHEET BY COATED ALUMINIUM-SILICON ALLOY AND METHOD FOR MANUFACTURING THE SAME}

The present invention relates to an aluminum-silicon coated steel sheet and a method for manufacturing the same, and more particularly, to a steel sheet coated with an aluminum-silicon alloy using a vacuum coating method and an oblique evaporation to improve corrosion resistance, heat resistance and reflectivity, and It relates to a manufacturing method.

In general, aluminum-silicon alloy is widely used as a surface treatment material for improving the corrosion resistance and heat resistance of the iron material. Steel plate coated with aluminum-silicon alloy can be applied to automobile exhaust system because it has high heat resistance, and the method of coating aluminum-silicon alloy on steel sheet is hot-dip plating method (application number: 10-2001-0022954, 10-2003-0409227). ) Is most commonly used, and this method has the advantage of being inexpensive and easily controlling the composition of the plating bath.

The aluminum coating layer containing silicon rather than the pure aluminum coating layer is also used in optical materials because it can be expected to improve the reflectance, vacuum coating method is used to apply the aluminum-silicon alloy coating layer in the optical field. Among the vacuum coating methods, a thermal vapor deposition method or an electron beam deposition method (application number: 10-2002-0051609, 10-1998-0051211, 10-1995-0000309, 10-1994-0007217) is widely used. If the aluminum reacts with oxygen or water molecules during coating, an oxide film is formed, resulting in a low reflectance.

When the sputtering method is used to synthesize the aluminum-silicon alloy coating layer, it is difficult to synthesize a high reflectance aluminum coating layer because sputtering is not easy to lower the process pressure to 10 ^-4 torr or less. In addition, when coating the metal by the sputtering method, since most of the coating layer has a columnar structure, the reflection density is low due to low density and high surface roughness of the coating layer, which results in a low reflectance. Porosity occurs between the columnar column and columnar column with low density of columnar structure, which is a disadvantage as a protective film to prevent corrosion.

The present invention for solving the above problems is to produce an aluminum-silicon alloy coating layer by an oblique deposition to provide a steel sheet with improved corrosion resistance, heat resistance and reflectance.

In one or more embodiments of the present invention, a method for coating a steel sheet using a sputtering process, comprising: forming a first oblique coating layer by coating an aluminum-silicon alloy on the steel sheet at a first oblique angle; Coating the aluminum-silicon alloy with a second comb angle having the same size and opposite direction as the first comb angle to form a second comb coating layer; may be provided with a steel sheet coating method. However, the first and second oblique angles are angles formed between the vertical component of the target and the vertical component of the specimen.

The aluminum-silicon alloy coating layer is two or more layers, and the aluminum-silicon alloy is characterized in that the silicon content of 3 to 15 weight percent (wt%).

The sizes of the first and second oblique angles may be 10 to 80 °, and may include washing and cleaning the steel sheet before forming the first oblique coating layer.

In addition, in one or more embodiments according to the present invention, an aluminum-silicon steel sheet coated by any one of the above methods may be provided, wherein the thickness of the coating layer of the steel sheet is 3 to 10 μm. It is done.

According to an embodiment of the present invention, the aluminum-silicon alloy target contains silicon and is deposited on the specimen at an oblique angle to form a multi-layered aluminum-silicon coating layer, thereby improving corrosion resistance, heat resistance, and reflectance.

1 is a schematic view of a sputtering coating apparatus used in the embodiment according to the present invention.
2 is a conceptual diagram of the oblique angle coating used in the embodiment according to the present invention.
3 is a conceptual diagram of a multilayer structure of an aluminum-silicon alloy according to an embodiment of the present invention.
4 is an evaluation result of the surface roughness of the aluminum, aluminum-silicon alloy coating layer according to an embodiment of the present invention.
5 is a reflectance evaluation result of the aluminum, aluminum-silicon alloy coating layer according to an embodiment of the present invention.
6 is a salt spray test results of the aluminum, aluminum-silicon alloy coating layer according to an embodiment of the present invention.
7 is a heat resistance evaluation results of the aluminum, aluminum-silicon alloy coating layer according to an embodiment of the present invention.
8 is a flowchart of a coating process according to an embodiment of the present invention.

Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. However, it is to be understood that the present invention is not limited to the disclosed embodiments, but may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. It is intended that the disclosure of the present invention be limited only by the terms of the appended claims. Like reference numerals refer to like elements throughout the specification.

In the embodiment according to the present invention, in order to improve the corrosion resistance, heat resistance and reflectance of the steel sheet, an oblique deposition method was used during the composition and sputtering process of the aluminum-silicon alloy.

The oblique deposition method is a method in which the specimen is inclined at an angle of 0 ° or more with respect to the vertical component of the target and the specimen, unlike the existing coating method in which the target and the specimen are placed in parallel with each other. When the oblique deposition method is used, the microstructure of the coating layer can be controlled, and a coating layer having various structures such as a tilted pillar, a spiral pillar, and a zigzag pillar structure can be synthesized. In the embodiment according to the present invention by introducing the oblique deposition method in the sputtering process to control the microstructure of the aluminum-silicon coating layer to synthesize a coating layer having a dense structure.

That is, in the embodiment according to the present invention by using a sputtering process and an oblique deposition by synthesizing the aluminum-silicon alloy coating layer having a dense structure to derive a coating method to improve the reflectance and increase the corrosion resistance of the substrate. In addition, a coating method that can improve the heat resistance characteristics that can protect the substrate even at high temperatures was derived.

8 illustrates a flow of a coating process according to an embodiment of the present invention. Hereinafter, an embodiment of the present invention will be described with reference to FIG. 8.

First, before coating the aluminum-silicon alloy on the substrate 70, the substrate 70 is cleaned (S100) to remove foreign substances on the substrate 70, and the substrate is cleaned to clean the surface of the cleaned substrate 70 so that the deposition is performed well. (S110).

Thereafter, the substrate 70 is inclined to coat the aluminum-silicon alloy on the substrate at a first bevel angle α to form a first bevel coating layer 110 (S120), and then the substrate 70 is first beveled. And the same size but the opposite direction is inclined at a second oblique angle (-α) to coat the aluminum-silicon alloy to form a second oblique coating layer 120 (S130).

In addition, in the embodiment according to the present invention it is possible to form a multi-layer coating layer by repeating the steps S120 and S130 several times.

As described above, in the embodiment according to the present invention, when fabricating the aluminum-silicon alloy coating layer by the oblique deposition, the specimen is inclined so that the distance between the target and the specimen is short and long. It is divided into a thick coated portion and a thin coated portion.

Because of this, because the thickness variation of the aluminum-silicon coating layer may cause an error in the evaluation of corrosion resistance in the embodiment according to the present invention solved this problem by forming a coating layer in a multi-layer.

The method of synthesizing the aluminum-silicon coating layer with the multilayer may include, for example, coating a first oblique coating layer at an oblique angle of 45 ° and coating a second oblique coating layer having the same thickness as the first oblique coating layer at an oblique angle of −45 °. The thickness of the aluminum-silicon coating layer coated on the specimen is to be kept constant.

As such, in order to maintain a constant thickness of the aluminum-silicon coating layer, the time for forming the first oblique coating layer 110 and the second oblique coating layer 120 should be the same.

In an embodiment according to the present invention, the first and second oblique angles are angles formed between the vertical component of the target and the vertical component of the specimen. The angle α of the oblique angle may be an acute angle, and is not particularly limited, but 10 to 80 ° is preferable. Since the growth of the coating layer is suppressed horizontally by a shadowing effect, a coating layer of 10 ° or more is usually formed, and when the size of the bevel angle is greater than 80 °, the inclination angle of the bevel coating layer 20 is close to the vertical, thereby improving hardness. Since the effect is insignificant, the size of the oblique angle is limited to the above range.

In addition, when the oblique angle deposition as in the embodiment according to the present invention is carried out in a high vacuum region, the nucleus formed in the initial stage of the coating is grown while maintaining a constant angle due to a shadowing effect to produce various geometric structures. Make. However, since sputtering as in the embodiment according to the present invention uses an inert gas in the process, the aluminum-silicon alloy coating layer is synthesized in a vacuum having a higher pressure than the high vacuum region (10 ^-4 to 10 ^-6 torr), thereby causing a square effect. Synthesis of the coating layer having a geometrical structure does not occur, and the columnar structure is suppressed by scattering and collision bombardment of ions.

Therefore, in the embodiment according to the present invention, while the growth of columnar tablets is suppressed when the aluminum-silicon alloy coating layer is synthesized, the density of the coating layer is improved and the surface roughness of the coating layer is lowered. As a result, the corrosion protection effect of the steel sheet is improved, and the reflectance is increased, thereby enhancing the appearance of the steel sheet. In addition, heat resistance is improved as compared with the aluminum plated steel sheet produced by conventional hot dip plating.

Hereinafter, embodiments of the present invention will be described in more detail.

In the embodiment according to the present invention, a cold rolled steel sheet was used as the substrate 70. The steel sheet was subjected to a degreasing step to remove the rust preventive oil because the rust preventive oil was infiltrated in order to prevent corrosion. The rust preventive oil of the steel plate was removed using a surfactant and washed with water. Water remaining on the surface of the steel sheet was dried with nitrogen gas or compressed air. When degreasing is completed, the steel sheet is ultrasonically cleaned with alcohol and acetone and mounted on a vacuum coating equipment.

1 is a schematic diagram of a sputtering coating apparatus used to coat an aluminum-silicon alloy on a steel sheet in an embodiment according to the present invention. Referring to FIG. 1, the vacuum coating equipment exhausts up to 10 ⁻⁶ torr after mounting the substrate 70. After evacuating, argon (Ar) gas is injected into the vacuum chamber 10 through the gas inlet 20, and when the degree of vacuum reaches 1ⅹ10 ^-2 torr, a DC voltage of about 800 V is applied to the substrate holder 60 to glow. The discharge is generated to clean the surface of the substrate for about 30 minutes. The substrate used a cold rolled steel sheet.

In this case, the injected gas is discharged to the outside through the exhaust port 90, and the degree of vacuum in the vacuum chamber 10 is measured by the vacuum gauge 80 attached to one side of the vacuum chamber 10. In addition, the rotating column 65 operated by the electric motor 62 rotates so that the substrate 70 is inclined.

When the cleaning of the steel sheet was completed, the vacuum equipment was evacuated to a basic pressure of 10 ⁻⁶ torr, and the steel sheet was inclined at the first oblique angle α using the electric motor 62. 2 is a conceptual diagram of the oblique coating used in the embodiment according to the present invention, as shown in FIG.

In the embodiment according to the present invention, the size α of the oblique angle was 0, 30, 45, 60, 90 °, and was performed for five oblique angles.

In this case, 0 ° means a state in which the substrate 70 is not tilted.

Thereafter, DC power was supplied to the sputtering source 30 using the DC power supply device 50 to generate plasma, and the aluminum-silicon alloy first beveled coating layer 110 was coated on the steel sheet.

At this time, the silicon content of the target 40 was 0, 3, 10 weight percent (wt%), respectively, and the intensity of the power applied to the sputtering source 30 was about 1.5 kW. When the coating of the first oblique coating layer 110 is finished, the steel sheet is inclined at a second oblique angle (−α) having the same size as that of the first oblique angle α and having opposite directions, and the same as the first oblique coating layer 110. The aluminum-silicon alloy second oblique coating layer 120 is coated under the process conditions.

3 illustrates a multilayer structure of the aluminum-silicon coating layer according to the embodiment of the present invention. In FIG. 3, the total thicknesses of the coating layers 110 and 120 were 3 to 10 μm.

The angle-coated aluminum-silicon coating layer measured the surface roughness and the relative reflectance in the visible region with a surface profiler and a spectrophotometer, respectively. In order to increase the accuracy of the measurement, the substrate used for surface roughness and reflectance measurement was made of silicon wafer.

Figure 4 shows the result of measuring the surface roughness of the aluminum, aluminum-silicon alloy coating layer according to an embodiment of the present invention, the pure aluminum is improved surface roughness as the size of the bevel angle but the silicon-containing alloy bevel angle The size did not change significantly. This suggests that silicon does not significantly affect surface roughness improvement.

Figure 5 shows the reflectance measurement results of the aluminum, aluminum-silicon alloy coating layer according to an embodiment of the present invention, it can be seen that the pure aluminum does not show a significant change in the reflectance even if the size of the oblique angle increases. However, at the oblique angle of 30 °, the highest reflectance was 96.5% in the coating layer containing 10 wt% of silicon. The coating layer having a silicon content of 3 wt% did not have a large change in reflectance due to the change in the oblique angle except for the oblique angle of 90 °.

In general, pure aluminum is coated on a steel sheet with a thickness of about 3 μm by a vacuum coating method, and then a salt spray test (ASTM B117) is performed to produce red blue color in about 72 hours.

Figure 6 shows the results of the salt spray test of the aluminum, aluminum-silicon alloy coating layer according to an embodiment of the present invention, referring to Figure 6 when not applying the oblique deposition, that is, the coating of the coating layer of the oblique angle 0 ° Comparing the salt spray results, it can be seen that as the content of silicon increases, the time of occurrence of red-blue red is increased. This is because silicon contributes to improving the corrosion resistance of the steel sheet.

The steel sheet coated with a multilayered aluminum-silicon alloy having a comb angle of 30 ° and a silicon content of 10 wt% was found to have red blue color over 200 hours. It can be seen that as the angle of inclination increases, the red-blue occurrence time of the alloy coating layer containing silicon decreases.

Figure 7 shows the results of the evaluation of the heat resistance of the aluminum, aluminum-silicon alloy coating layer according to an embodiment of the present invention, referring to Figure 7 after changing the weight of the aluminum-silicon coated steel sheet after heating to 500 ℃ 4 As a result, it can be seen that as the silicon content increases, the weight reduction width decreases.

In other words, in the embodiment according to the present invention, a dense aluminum-silicon coating layer was fabricated on the steel sheet using sputtering and inclined deposition, and the coating layer exhibited excellent corrosion resistance and reflectance when the content of silicon was 10 wt% and the inclination was 30 °. Could get When the silicon content is 10 wt%, corrosion resistance can be observed without an oblique deposition, which is improved by adding silicon to pure aluminum. In addition, it was confirmed that the weight reduction width of the coating layer was low even after the heat treatment when the silicon content increased in the heat resistance evaluation results. According to the experimental results as described above, the content of silicon in the Example according to the present invention was limited to 3 to 15 weight percent (wt%).

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, You will understand.

It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. The scope of the present invention is defined by the appended claims rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be interpreted as being included in the scope of the present invention .

DESCRIPTION OF SYMBOLS 10 Vacuum chamber 20 Gas inlet 30 Sputtering source
40: target 50: power supply 60: substrate holder
62: motor 65: rotating pillar 70: substrate
80: vacuum gauge 90: exhaust port 100: steel sheet
110: first oblique coating layer 120: second oblique coating layer

Claims (7)

In the steel sheet coating method using a sputtering process,
Coating an aluminum-silicon alloy on the steel sheet at a first oblique angle to form a first oblique coating layer;
Coating the aluminum-silicon alloy with a second comb angle that is the same size and opposite in direction as the first comb angle to form a second comb angle coating layer;
Steel plate coating method comprising a.
However, the first and second oblique angles are angles formed between the vertical component of the target and the vertical component of the specimen. The method of claim 1,
The aluminum-silicon alloy coating layer is a steel sheet coating method, characterized in that more than two layers. The method of claim 1,
The aluminum-silicon alloy is a steel sheet coating method, characterized in that the silicon content of 3 to 15 weight percent (wt%). The method of claim 1,
Steel sheet coating method characterized in that the size of the first and second oblique angle is 10 ~ 80 °. The method of claim 1,
Before forming the first oblique coating layer, the steel sheet coating method comprising the step of washing and cleaning the steel sheet. An aluminum-silicon coated steel sheet coated by the method of any one of claims 1 to 5. The method according to claim 6,
Aluminum-silicon coated steel sheet, characterized in that the thickness of the coating layer is 3 ~ 10㎛.

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