KR20020078242A - aluminum surface treatment method - Google Patents

aluminum surface treatment method Download PDF

Info

Publication number
KR20020078242A
KR20020078242A KR1020010018295A KR20010018295A KR20020078242A KR 20020078242 A KR20020078242 A KR 20020078242A KR 1020010018295 A KR1020010018295 A KR 1020010018295A KR 20010018295 A KR20010018295 A KR 20010018295A KR 20020078242 A KR20020078242 A KR 20020078242A
Authority
KR
South Korea
Prior art keywords
aluminum
sealing
temperature
surface treatment
oxide film
Prior art date
Application number
KR1020010018295A
Other languages
Korean (ko)
Other versions
KR100400104B1 (en
Inventor
정희영
Original Assignee
두라금속공업 (주)
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 두라금속공업 (주) filed Critical 두라금속공업 (주)
Priority to KR10-2001-0018295A priority Critical patent/KR100400104B1/en
Publication of KR20020078242A publication Critical patent/KR20020078242A/en
Application granted granted Critical
Publication of KR100400104B1 publication Critical patent/KR100400104B1/en

Links

Classifications

    • CCHEMISTRY; METALLURGY
    • C25ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25DPROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D11/00Electrolytic coating by surface reaction, i.e. forming conversion layers
    • C25D11/02Anodisation
    • C25D11/04Anodisation of aluminium or alloys based thereon
    • CCHEMISTRY; METALLURGY
    • C25ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25DPROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D11/00Electrolytic coating by surface reaction, i.e. forming conversion layers
    • C25D11/02Anodisation
    • C25D11/04Anodisation of aluminium or alloys based thereon
    • C25D11/18After-treatment, e.g. pore-sealing
    • C25D11/24Chemical after-treatment

Abstract

PURPOSE: A surface treatment method of aluminum or aluminum alloys is provided to form alkali resistant hard film on the surface of aluminum or aluminum alloys at even ambient temperatures. CONSTITUTION: In a surface treatment method of aluminum or aluminum alloys consisting of anodizing and sealing, the method is characterized in that during anodizing the temperature of electrolysis bath is controlled to be 10 to 15 deg.C and 20 to 80 V of voltage is applied to the electrolysis bath; and sealing consists of primary sealing using metal fluoride salts and secondary sealing using organic acid.

Description

알루미늄 또는 알루미늄합금의 표면처리방법{aluminum surface treatment method}Surface treatment method of aluminum or aluminum alloy

본 발명은 알루미늄 또는 알루미늄합금의 표면처리방법에 관한 것으로서, 보다 상세하게는 상온에서 처리하여도 경질피막을 얻을 수 있으며, 내알칼리성이 우수한 새로운 구성의 알루미늄 또는 알루미늄합금의 표면처리방법에 관한 것이다.The present invention relates to a surface treatment method of aluminum or an aluminum alloy, and more particularly, to a hard film obtained by treatment at room temperature, and to a surface treatment method of aluminum or aluminum alloy of a new configuration having excellent alkali resistance.

알루미늄은 대단히 활성이기 때문에 공기 중에서 표면이 자연산화된다. 따라서 일반적으로 알루미늄이나 알루미늄 합금으로 제품을 만드는 경우에는 제품의 표면을 인위적으로 양극산하시켜 산화피막을 형성한다. 그리고 이때 내구성이 높은 고품질의 제품을 얻기 위해 경도가 높은 경질산화피막이 형성되도록 한다. 이러한 경질산화피막에 대해서는 엄밀한 정의나 규격이 정해져 있는 것은 아니지만, 일반적으로는 0℃ 부근의 저온에서 생성된 견고한 피막으로 적어도 30㎛ 이상의 두꺼운 피막을 경질산회피막이라 한다.Aluminum is so active that its surface naturally oxidizes in air. Therefore, in general, when the product is made of aluminum or aluminum alloy, the surface of the product is artificially anodized to form an oxide film. In this case, a hard oxide film having a high hardness is formed to obtain a high quality product having high durability. Although no rigid definition or standard is specified for such hard oxide film, generally, a hard film formed at a low temperature near 0 ° C. and a thick film of at least 30 μm or more are referred to as hard acid ash film.

이러한 경질산화피막을 얻기 위해서는 전해욕의 온도를 0℃ 이하로하여80~90V 정도의 고전압에서 처리하여야 하는데, 이때 전해욕의 온도를 0℃ 이하로 유지하여 처리하는 것이 가장 중요하다. 따라서 전해욕의 온도를 0℃이하의 저온으로 유지조절하기 위해서는 냉동기와 같은 별도의 장치를 갖추어야 하므로 많은 설비비가 요구되고, 이에 따라 제품의 코스트가 상승되었다.In order to obtain such a hard oxide film, the temperature of the electrolytic bath should be treated at a high voltage of about 80 to 90V with the temperature of 0 ° C. or lower. In this case, it is most important to maintain the temperature of the electrolytic bath at 0 ° C. or lower. Therefore, in order to maintain and control the temperature of the electrolytic bath at a low temperature of 0 ° C. or more, a separate device such as a freezer is required, thus requiring a lot of equipment costs, thereby increasing the cost of the product.

한편, 이와 같은 점에 대해 전해욕의 온도를 낮추지 않고도 경질산화피막을 형성할 수 있는 방법이 제안되기도 하였으며, 그 중에는 설포살리실릭산 등의 유기산을 전해욕에 첨가하여 상온에 가까운 욕온에서 처리하는 방법 등이 있다. 그러나 이와 같이 욕온을 0℃이상으로 하여 양극산화하는 경우에는 0℃ 이하의 욕온에서 처리하는 경우보다 피막의 경도가 낮다는 단점이 있다.On the other hand, a method for forming a hard oxide film without lowering the temperature of the electrolytic bath has also been proposed. Among these, organic acids such as sulfosalicylic acid are added to the electrolytic bath and treated at a bath temperature close to room temperature. Method and the like. However, when anodizing at a bath temperature of 0 ° C. or higher, there is a disadvantage in that the hardness of the film is lower than that at the bath temperature of 0 ° C. or lower.

또한, 일반적으로 사용되는 주방세제는 중성 또는 약알칼리성인데, 종래의 방법으로 양극산화처리된 제품들은 내약칼리성이 비교적 낮기 때문에 전술한 바와 같은 약알칼리 세제로 다수회 반복세척하면 제품이 세제에 의해 변색되어 제품의 표면에 얼룩이 생기는 등 외관상 좋지 않았다.In addition, the commonly used dishwashing detergent is neutral or weak alkali, since the conventional anodized products are relatively low in alkali resistance, if the product is repeatedly washed several times with the weak alkali detergent as described above, It was discolored and stained on the surface of the product.

본 발명은 상기의 문제점을 해결하기 위한 것으로서, 본 발명의 목적은 상온에서 처리하여도 경질의 피막을 얻을 수가 있으며, 산화피막에 자연발색을 부여할 수 있는 새로운 구성의 알루미늄 또는 알루미늄합금의 표면처리방법을 제공하는 것이다.The present invention has been made to solve the above problems, and an object of the present invention is to obtain a hard coating even when treated at room temperature, and the surface treatment of aluminum or aluminum alloy of a new configuration that can give a natural color to the oxide film To provide a way.

본 발명에 따르면, 알루미늄 또는 알루미늄합금의 표면에 산화피막을 형성하는 양극산화과정과, 상기 산화피막을 봉공처리하는 후처리과정을 포함하여 이루어지는 알루미늄 또는 알루미늄합금의 표면처리방법에 있어서, 상기 양극산화과정에서는 전해욕의 온도를 10~15℃, 전압을 20~80V로 하여 경질양극산화피막을 형성하고, 상기 후처리과정은 불화금속염 용액으로 봉공하는 1차봉공과정과, 유기산염용액으로 봉공하는 2차봉공을 포함하여 이루어진 것을 특징으로 하는 알루미늄 또는 알루미늄 합금의 표면처리방법이 제공된다.According to the present invention, in the surface treatment method of aluminum or aluminum alloy comprising an anodization process of forming an oxide film on the surface of aluminum or aluminum alloy, and a post-treatment process of sealing the oxide film, the anodization In the process, the temperature of the electrolytic bath is 10-15 ° C., and the voltage is 20-80 V to form a hard anodized film. The post-treatment process is a primary sealing process of sealing with a metal fluoride solution, and sealing with an organic acid salt solution. Provided is a method for surface treatment of aluminum or an aluminum alloy, comprising a secondary rod.

이하, 본 발명을 구체적으로 설명하면 다음과 같다. 본 발명은 상온에서 양극산화처리하여도 경질산화피막을 얻을 수 있으며, 내식성 및 내약칼리성을 증가시킬 수 있는 알루미늄 또는 알루미늄합금의 표면처리방법에 관한 것이다. 이러한 본 발명을 냄비와 같은 주방용기에 적용하여 설명하면 다음과 같다.Hereinafter, the present invention will be described in detail. The present invention relates to a surface treatment method of aluminum or aluminum alloy, which can obtain a hard oxide film even by anodizing at room temperature, and can increase corrosion resistance and chemical resistance. When explaining the present invention applied to a kitchen container such as a pan as follows.

먼저, 알루미늄 또는 알루미늄 합금으로 성형된 주방용기를 약알칼리에서 탈지하고 수세하여, 용기의 표면에 부착되어 있을 수도 있는 불순물을 제거하다. 그런 다음, 용기를 양극산화처리한다. 이때에는 황산전해액을 사용하는데, 전해액의 온도를 종래의 경질피막처리시의 온도 보다 상당히 높은 10~15℃로 하여 처리한다. 그리고 전압은 종래의 저온 산화피막처리시 보다는 상당히 낮은 60~40V로 하고 전류밀도는 3A/dm2로 한다.First, the kitchen vessel formed of aluminum or an aluminum alloy is degreased with weak alkali and washed with water to remove impurities that may be attached to the surface of the container. The vessel is then anodized. At this time, sulfuric acid electrolyte is used, and the temperature of the electrolyte is treated at 10 to 15 ° C., which is considerably higher than the temperature of the conventional hard coating treatment. In addition, the voltage is considerably lower than that of the conventional low temperature anodized film, and the voltage is 60 to 40 V and the current density is 3 A / dm 2 .

일반적으로 전해액의 온도가 높으면 산화피막의 기공의 직경이 커져서 빛이완전히 흡수되지 못하고, 입사된 빛의 일부분은 반사되어 산란하게 된다. 따라서 본 발명에서와 같이 전해액의 온도를 10~15℃로 유지하여 산화피막을 형성하면, 산화피막에 형성되는 기공의 직경이 커지게 되어 산화피막의 표면이 불규칙한 계면을 가지게 된다. 그리고 이 산화피막에 입사되는 빛은 완전히 흡수되지 못하고 반사,산란되어 흑회색을 발하게 된다.In general, when the temperature of the electrolyte is high, the diameter of the pores of the oxide film is increased so that the light is not completely absorbed, and a part of the incident light is reflected and scattered. Therefore, when the oxide film is formed by maintaining the temperature of the electrolyte at 10 to 15 ° C. as in the present invention, the diameter of the pores formed in the oxide film is increased, so that the surface of the oxide film has an irregular interface. The light incident on the oxide film is not completely absorbed, but is reflected and scattered, causing black gray.

한편, 전술한 바와 같이, 상온에서 생성된 산화피막은 저온에서 생성된 것보다 경도가 떨어지는 단점이 있는데, 본 발명에서는 이러한 단점을 보완하고 경도가 높은 경질산화피막을 얻기 위해 후처리인 봉공처리를 다단계로 나누어 처리한다.On the other hand, as described above, the oxide film produced at room temperature has a disadvantage that the hardness is lower than that produced at low temperature, in the present invention to compensate for this disadvantage and to obtain a high hardness hard oxide film is a post-treatment sealing process Process in multiple stages.

먼저, 불화금속염 용액을 봉공액으로 하여 1차봉공 하는데, 이때에는 봉공액의 온도를 약 25~30℃로 하여 처리한다. 그런 다음, 유기산염을 봉공액으로 하여 2차봉공한다. 이때에는 상기 1차봉공시 보다 높은 온도에서 봉공처리하는데, 봉공액의 온도를 약 50~60℃ 정도로 하여 처리한다. 바람직하게는 상기 유기산염으로는 아세트산염을 사용한다. 이와 같이 2차봉공처리 한 다음에는 대략 90℃정도의 고온수에서 침지하여 마무리한다. 이와 같이 하면, 산화피막의 다공들이 효과적으로 봉공되어 내식성과 내알칼리성이 우수한 제품을 얻을 수 있다. 따라서 이와 같은 방법으로 제조된 주방용기는 알칼리성인 주방세제로 반복적으로 세척하여도 손상되지 않는다.First, the metal fluoride salt solution is used as a sealing solution, and the first sealing operation is performed. At this time, the temperature of the sealing solution is treated at about 25 to 30 ° C. Then, secondary sealing is performed using organic acid salt as sealing solution. At this time, the sealing is performed at a higher temperature than the first sealing, and the temperature of the sealing is about 50 to 60 ° C. Preferably, acetate is used as the organic acid salt. After finishing the secondary sealing in this way, the finish is immersed in hot water of about 90 ℃. In this way, pores of the oxide film are effectively sealed to obtain a product having excellent corrosion resistance and alkali resistance. Therefore, the kitchen container prepared in this way is not damaged even if it is repeatedly washed with alkaline kitchen detergent.

실시예 1Example 1

알루미늄으로 제작된 냄비를 다음과 같은 방법으로 양극산화처리하였다. 먼저, 상기 냄비의 표면을 NaOH용액으로 탈지한 다음, 욕온이 10~15℃로 유지되는 15% 황산전해액을 사용하여 전압을 50~40V로 하고 전류밀도는 DC 3A/dm2로 하여 약 30분 정도 처리하여 양극산화피막을 형성하였다. 그런 다음, 50~80g/ℓ 농도의 불화니켈 용액에 약 30분정도 침지시켜 1차봉공하고, 이를 수세한 후 다시 4~8g/ℓ 농도의 니켈아세테이트 용액에 약 30분 정도 침지시켜 2차봉공처리하였다. 이어서 90℃ 정도의 고온수에 침지시켜 마무리하였다. 이와 같은 방법으로 처리된 냄비와 종래의 방법으로 양극산화처리된 냄비를 시중에서 판매되는 알칼리세제(회사명:PROCTOR & GAMBLE, 제품명:CASCADE pH:10)로 식기세척기에서 10회, 20회, 30회 반복세척 한 다음, 색상의 변화를 관찰하였다. 그 결과는 <표 1>과 같았다.The pot made of aluminum was anodized in the following manner. First, the surface of the pot is degreased with NaOH solution, and then the voltage is set to 50 to 40V using a 15% sulfuric acid electrolyte solution in which the bath temperature is maintained at 10 to 15 ° C., and the current density is about 3 minutes to DC 3A / dm 2 . The degree of treatment was to form anodized film. Then, the first seal is immersed in a nickel fluoride solution at a concentration of 50 to 80 g / ℓ for about 30 minutes, and washed again and then immersed in a nickel acetate solution at a concentration of 4 to 8 g / ℓ for about 30 minutes, and the second seal is made. Treated. Subsequently, the finish was immersed in hot water at about 90 ° C. Pots treated in this way and pots anodized by conventional methods are commercially available in dishwashers with alkali cleaners (company name: PROCTOR & GAMBLE, product name: CASCADE pH: 10), 10 times, 20 times, 30 times. After repeated washings, color changes were observed. The results are shown in <Table 1>.

<표 1>TABLE 1

항 목Item A사제품A company product B사제품Company B 본 발명에의한 제품Product according to the present invention 50회 반복세척50 repetitive washes 변화없음No change 변화없음No change 변화없음No change 100회 반복세척100 repetitive washes 변색discoloration 변화없음No change 변화없음No change 150회 반복세척150 repetitive washes 변색discoloration 변색discoloration 변화없음No change 200회 반복세척200 repetitive washes 변색discoloration 변색discoloration 변화없음No change

<표 1>에서 알 수 있는 바와 같이, 종래의 양극산화방법으로 처리된 제품들은 50~100회 정도 반복 세척하면 표면이 변색되어 얼룩이 생기기 시작하였으나, 본 발명에 의한 방법으로 처리된 제품은 200회 이상 반복 세척하여도 아무런 변화가 없었다. 이 결과 본 발명에 의한 방법으로 처리된 제품은 내알칼리성이 우수함을 알 수 있다.As can be seen in Table 1, the products treated by the conventional anodization method began to discolor when the surface was repeatedly washed about 50-100 times, but the product treated by the method according to the present invention 200 times There was no change even after repeated washing. As a result, it can be seen that the product treated by the method according to the present invention has excellent alkali resistance.

실시예 2Example 2

실시예 1에서와 같은 샘플에 형성된 표면피막의 경도를 테스트한 결과 <표 2>와 같았다.As a result of testing the hardness of the surface coating formed on the sample as in Example 1, it was as shown in Table 2.

<표 2>TABLE 2

항 목Item A사제품A company product B사제품Company B 본 발명에의한 제품Product according to the present invention 경도(HB)Hardness (HB) 300300 310310 450450

<표 2>에서 알 수 있는 바와 같이, 본 발명에 의한 방법으로 처리된 제품은 표면 강도가 종래의 제품에 비해 약 50% 이상 높았다.As can be seen from Table 2, the products treated by the method according to the invention had a surface strength of at least about 50% higher than that of conventional products.

이상에서와 같이 본 발명에 의하면, 상온에서 양극산화처리하여도 경질산화피막을 얻을 수 있으며, 내식성 및 내약칼리성을 증가시킬 수 있으며, 별도의 발색처리를 하지 않고도 자연발색에 의해 독특한 색상을 부여할 수 있는 알루미늄 또는 알루미늄합금의 표면처리방법을 제공할 수 있다. 이러한 본 발명은 전해액의 온도를 저온으로 유지하기 위한 별도의 장비가 필요 없으므로, 종래의 저온 양극산화방법에 비해 설비비가 적게 들므로 제품의 코스트가 저렴하다. 또한, 별도의 발색처리를 하지 않아도 미려한 흑회색의 색상이 부여되므로 제작공정이 단축되며, 특히 다단계로 처리되는 봉공과정에 의해 높은 경도와 내식성 및 내악칼리성이 우수한 고품질의 제품을 얻을 수 있다.As described above, according to the present invention, even when anodized at room temperature, a hard oxide film can be obtained, and corrosion resistance and chemical resistance can be increased, and a unique color can be given by natural coloration without a separate coloring treatment. It is possible to provide a surface treatment method of aluminum or aluminum alloy. Since the present invention does not require a separate equipment for maintaining the temperature of the electrolyte at a low temperature, the cost of the product is low because the equipment cost is less than the conventional low temperature anodizing method. In addition, it is given a beautiful black gray color without a separate color development process is shortened the manufacturing process, in particular by a multi-stage sealing process can be obtained a high-quality product excellent in high hardness, corrosion resistance and evil-proof.

Claims (1)

알루미늄 또는 알루미늄합금의 표면에 산화피막을 형성하는 양극산화과정과, 상기 산화피막을 봉공처리하는 후처리과정을 포함하여 이루어지는 알루미늄 또는 알루미늄합금의 표면처리방법에 있어서, 상기 양극산화과정에서는 전해욕의 온도를 10~15℃, 전압을 20~80V로 하여 경질양극산화피막을 형성하고, 상기 후처리과정은 불화금속염 용액으로 봉공하는 1차봉공과정과, 유기산염용액으로 봉공하는 2차봉공을 포함하여 이루어진 것을 특징으로 하는 알루미늄 또는 알루미늄 합금의 표면처리방법.An anodizing process of forming an oxide film on the surface of aluminum or an aluminum alloy, and a post-treatment process of sealing the oxide film, the method of surface treatment of aluminum or aluminum alloy, wherein the anodization A hard anodized film is formed at a temperature of 10 to 15 ° C. and a voltage of 20 to 80 V. The post-treatment process includes a primary sealing process for sealing with a metal fluoride solution and a secondary sealing for sealing with an organic acid salt solution. Surface treatment method of aluminum or aluminum alloy, characterized in that consisting of.
KR10-2001-0018295A 2001-04-06 2001-04-06 aluminum surface treatment method KR100400104B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
KR10-2001-0018295A KR100400104B1 (en) 2001-04-06 2001-04-06 aluminum surface treatment method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
KR10-2001-0018295A KR100400104B1 (en) 2001-04-06 2001-04-06 aluminum surface treatment method

Publications (2)

Publication Number Publication Date
KR20020078242A true KR20020078242A (en) 2002-10-18
KR100400104B1 KR100400104B1 (en) 2003-09-29

Family

ID=27700074

Family Applications (1)

Application Number Title Priority Date Filing Date
KR10-2001-0018295A KR100400104B1 (en) 2001-04-06 2001-04-06 aluminum surface treatment method

Country Status (1)

Country Link
KR (1) KR100400104B1 (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101291062B1 (en) * 2013-04-30 2013-08-01 주식회사 모아기술 Method of surface treatment for exterior decor of car
KR102403216B1 (en) 2022-03-15 2022-05-30 (주)위드엘씨 Coating composition for protecting anodic oxide layer and element of semiconductor manufacturing apparatus using the smae
KR102507838B1 (en) 2022-07-25 2023-03-08 (주)위드엘씨 Coating composition for protecting anodic oxide layer, having fluorine-containing alkoxy silane

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3098985U (en) * 2003-07-01 2004-03-18 有限会社和田挽物製作所 Rotating hair iron

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101291062B1 (en) * 2013-04-30 2013-08-01 주식회사 모아기술 Method of surface treatment for exterior decor of car
KR102403216B1 (en) 2022-03-15 2022-05-30 (주)위드엘씨 Coating composition for protecting anodic oxide layer and element of semiconductor manufacturing apparatus using the smae
KR102507838B1 (en) 2022-07-25 2023-03-08 (주)위드엘씨 Coating composition for protecting anodic oxide layer, having fluorine-containing alkoxy silane

Also Published As

Publication number Publication date
KR100400104B1 (en) 2003-09-29

Similar Documents

Publication Publication Date Title
US5792335A (en) Anodization of magnesium and magnesium based alloys
CN103334140B (en) The golden yellow dyeing of aluminium alloy anode oxide room temperature
US5674371A (en) Process for electrolytically treating aluminum and compositions therefor
CN105063716B (en) A kind of horniness anode oxide film enclosure method for improving alkali resistance
US20100143622A1 (en) Process for providing aluminium cookware with a copper coating
US2703781A (en) Anodic treatment of aluminum surfaces
KR100400104B1 (en) aluminum surface treatment method
US4939001A (en) Process for sealing anodized aluminum
JPH03277797A (en) Sealing treatment of aluminum anodically oxidized film
NO833388L (en) PROCEDURE FOR SURFACE TREATMENT OF ALUMINUM AND ALUMINUM ALLOYS
CA1134774A (en) Anodising aluminium
JPS6210299A (en) Formation of colored coated film for titanium or titanium alloy
US4430169A (en) Method of producing green coatings on aluminum and aluminum alloys
JPH11236698A (en) Corrosion resistant magnesium material product having brightness of metallic bare surface and its production
KR101438676B1 (en) Coloring method by anodizing
KR100266454B1 (en) A method for coloring nonferrous metal using ti-plating
US3275537A (en) Process of anodizing aluminum
JPS5827997A (en) Pretreatment of stainless steel for color formation
JPS60138095A (en) Method of coloring anodically oxidized aluminum product
US3397127A (en) Method and bath for electroplating gold
JPH03207895A (en) Electrolytic treatment of aluminum and aluminum alloy
US3057761A (en) Coloring oxide coated aluminum and product
JPH0273993A (en) Electrolytic coloration bath of surface of anodic oxidized aluminum
US5009756A (en) Chemical method of avoiding a rainbow effect caused by the layer of oxide produced upon the brightening of parts of aluminum or aluminum alloys
JPS6196086A (en) Surface treatment of aluminum or aluminum alloy

Legal Events

Date Code Title Description
A201 Request for examination
E902 Notification of reason for refusal
E701 Decision to grant or registration of patent right
GRNT Written decision to grant
LAPS Lapse due to unpaid annual fee