JP2005281717A - Method for forming chemical conversion-treated film of magnesium alloy - Google Patents
Method for forming chemical conversion-treated film of magnesium alloy Download PDFInfo
- Publication number
- JP2005281717A JP2005281717A JP2004092941A JP2004092941A JP2005281717A JP 2005281717 A JP2005281717 A JP 2005281717A JP 2004092941 A JP2004092941 A JP 2004092941A JP 2004092941 A JP2004092941 A JP 2004092941A JP 2005281717 A JP2005281717 A JP 2005281717A
- Authority
- JP
- Japan
- Prior art keywords
- chemical conversion
- magnesium alloy
- film
- coating
- mass
- Prior art date
- Legal status (The legal status 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 status listed.)
- Pending
Links
Landscapes
- Chemical Treatment Of Metals (AREA)
Abstract
Description
本発明はアルミニウム含有量が５.５〜７.５質量％である比強度の高いマグネシウム合金の表面に耐食性、塗膜密着性に優れた化成処理皮膜を形成する方法に関し、より詳しくは、マグネシウム合金の表面の溶出量を制御してエッチング処理し、その後特定の組成且つ特定の付着量の化成処理皮膜が形成されるように化成処理することにより比強度の高いマグネシウム合金の表面に耐食性、塗膜密着性に優れた化成処理皮膜を形成する方法に関する。 The present invention relates to a method of forming a chemical conversion film excellent in corrosion resistance and coating film adhesion on the surface of a magnesium alloy having a high specific strength with an aluminum content of 5.5 to 7.5% by mass. Etching is performed by controlling the amount of elution on the surface of the alloy, followed by chemical conversion treatment to form a chemical conversion coating with a specific composition and specific adhesion amount, thereby providing corrosion resistance and coating on the surface of the magnesium alloy having a high specific strength. The present invention relates to a method for forming a chemical conversion film having excellent film adhesion.
近年、各種産業分野において、軽量で、比強度に優れ且つリサイクル性にも優れているマグネシウム合金が注目を浴びており、その用途が広まってきている。しかし、マグネシウム合金はアルミニウム系材料、鉄系材料等に比べて耐食性に劣るという問題点がある。それで、マグネシウム合金の耐食性を改善するために様々な表面処理法や塗装法が提案されている。 In recent years, magnesium alloys, which are lightweight, excellent in specific strength and excellent in recyclability, have attracted attention in various industrial fields, and their uses are spreading. However, magnesium alloys have a problem that they are inferior in corrosion resistance compared to aluminum-based materials and iron-based materials. Therefore, various surface treatment methods and coating methods have been proposed to improve the corrosion resistance of magnesium alloys.
例えば、ダイカスト法あるいはチクソモールド法により製造されるＡＺ９１材鋳造製品等をノンクロム系化成処理溶液で表面処理して、裸耐食性、防錆性、塗膜密着性、塗膜耐食性を改善すると共に、電磁波シールド性を有効に保持し得るように低電気抵抗率を有する化成処理皮膜を形成することが提案されている（例えば、特許文献１参照。）。 For example, surface treatment of AZ91 cast products manufactured by die casting or thixomold method with a non-chromium chemical conversion treatment solution improves bare corrosion resistance, rust prevention, coating adhesion, coating corrosion resistance, and electromagnetic waves It has been proposed to form a chemical conversion film having a low electrical resistivity so that the shielding property can be effectively maintained (see, for example, Patent Document 1).
また、ＡＺ３１Ｂ等に代表され、押し出し材や圧延材として用いられ、アルミニウム含有量が７.５質量％以下と比較的少ない展伸用マグネシウム合金について、その表面からの溶出量が５ｇ／ｍ2以下となるように制御して無機酸又は有機酸でエッチング処理を行い、その後にカルシウムイオン、マンガンイオン及びリン酸イオンを含有する化成処理溶液を用いて表面処理を行って防錆性、塗膜密着性に優れる化成処理皮膜を形成することも提案されている（例えば、特許文献２参照。）。 Also, leaching magnesium alloy with a relatively small aluminum content of 7.5% by mass or less, represented by AZ31B and used as an extruded material or a rolled material, has an elution amount from the surface of 5 g / m 2 or less. Etching with an inorganic or organic acid under controlled conditions, followed by a surface treatment using a chemical conversion solution containing calcium, manganese and phosphate ions to prevent rust and paint adhesion It has also been proposed to form a chemical conversion film having excellent properties (see, for example, Patent Document 2).
アルミニウム含有量が７.５質量％以下である展伸用マグネシウム合金の中でもより高い比強度が要求される場合には、アルミニウム含有量が５.５〜７.５質量％程度であるマグネシウム合金、例えばＡＺ６１等を用いる必要がある。アルミニウム含有量が５.５〜７.５質量％程度であるマグネシウム合金の耐食性は一般的にはＡＺ３１Ｂマグネシウム合金とほぼ同等である。しかし、アルミニウム含有量が５.５〜７.５質量％であるマグネシウム合金を特開２００３−２８６５８２号公報に記載された発明の好ましい範囲、実施例に記載された範囲で処理しても、後記の比較例のデータからも明らかなように十分な長期耐食性を得ることはできない。 When a higher specific strength is required among the magnifying magnesium alloys having an aluminum content of 7.5% by mass or less, a magnesium alloy having an aluminum content of about 5.5 to 7.5% by mass, For example, it is necessary to use AZ61 or the like. In general, the corrosion resistance of a magnesium alloy having an aluminum content of about 5.5 to 7.5% by mass is substantially equal to that of an AZ31B magnesium alloy. However, even if a magnesium alloy having an aluminum content of 5.5 to 7.5% by mass is treated within the preferable range of the invention described in JP-A No. 2003-286582, the range described in the examples, it will be described later. As is clear from the data of the comparative example, sufficient long-term corrosion resistance cannot be obtained.
本発明は、ＡＺ６１等のアルミニウム含有量が５.５〜７.５質量％である比強度の高いマグネシウム合金の表面に長期耐食性、塗膜密着性に優れた化成処理皮膜を形成する方法を提供することを目的としている。 The present invention provides a method for forming a chemical conversion film excellent in long-term corrosion resistance and coating film adhesion on the surface of a magnesium alloy having a high specific strength with an aluminum content of 5.5 to 7.5% by mass, such as AZ61. The purpose is to do.
本発明等は上記の目的を達成するために鋭意検討した結果、マグネシウム合金としてアルミニウム含有量が５.５〜７.５質量％である比強度の高いマグネシウム合金を用い、マグネシウム合金の表面の溶出量を制御してエッチング処理し、その後特定の組成且つ特定の付着量の化成処理皮膜が形成されるように化成処理することにより上記の目的が達成されることを見いだし、本発明を完成した。 As a result of intensive studies to achieve the above object, the present invention and the like have used a magnesium alloy having a high specific strength with an aluminum content of 5.5 to 7.5% by mass as the magnesium alloy, and the elution of the surface of the magnesium alloy. The present invention was completed by finding that the above-mentioned object was achieved by performing an etching treatment while controlling the amount, and then performing a chemical conversion treatment so that a chemical conversion treatment film having a specific composition and a specific adhesion amount was formed.
即ち、本発明のマグネシウム合金の化成処理皮膜の形成方法は、マグネシウム合金の表面をその表面の溶出量が５ｇ／ｍ2以下となるように制御して無機酸又は有機酸によりエッチング処理し、その後、カルシウムイオン、マンガンイオン及びリン酸イオンを含有する溶液を用いてマグネシウム合金の表面に化成処理皮膜を形成する方法において、該マグネシウム合金としてアルミニウム含有量が５.５〜７.５質量％である比強度の高いマグネシウム合金を用い、また化成処理皮膜の付着量がＣａ、Ｍｎ及びＰの３元素の合計量で５５０〜１０００ｍｇ／ｍ2であり且つ化成処理皮膜中のＣａ、Ｍｎ及びＰの質量比がＭｎ：Ｃａ：Ｐ＝１：１〜２：３.５〜５となるように化成処理することを特徴とする。 That is, in the method for forming a chemical conversion treatment film of a magnesium alloy according to the present invention, the surface of the magnesium alloy is controlled to have an elution amount of 5 g / m 2 or less and etched with an inorganic acid or an organic acid. In the method of forming a chemical conversion film on the surface of a magnesium alloy using a solution containing calcium ions, manganese ions and phosphate ions, the magnesium alloy has an aluminum content of 5.5 to 7.5% by mass. A magnesium alloy having a high specific strength is used, and the amount of the chemical conversion coating is 550 to 1000 mg / m 2 in terms of the total amount of the three elements Ca, Mn and P, and the mass of Ca, Mn and P in the chemical conversion coating. Chemical conversion treatment is performed such that the ratio is Mn: Ca: P = 1: 1 to 2: 3.5-5.
本発明のマグネシウム合金の化成処理皮膜の形成方法を採用することにより、アルミニウム含有量が５.５〜７.５質量％である比強度の高いマグネシウム合金の表面に長期耐食性、塗膜密着性に優れた化成処理皮膜を形成することができる。 By adopting the method for forming a chemical conversion treatment film of a magnesium alloy according to the present invention, the surface of a magnesium alloy having a high specific strength with an aluminum content of 5.5 to 7.5% by mass has long-term corrosion resistance and coating film adhesion. An excellent chemical conversion film can be formed.
以下に、本発明を具体的に説明する。 The present invention will be specifically described below.
本発明のマグネシウム合金の化成処理皮膜の形成方法で用いるマグネシウム合金は、比強度の一層高いマグネシウム合金の用途を考慮して、アルミニウム含有量が５.５〜７.５質量％である比強度の高いマグネシウム合金、例えばＡＺ６１、ＡＺ６１Ａ等であり、押し出し加工、圧延加工、あるいは引き抜き加工したマグネシウム合金製品の表面に化成処理皮膜を形成することが好ましい。 The magnesium alloy used in the method for forming a chemical conversion film of a magnesium alloy according to the present invention has a specific strength with an aluminum content of 5.5 to 7.5% by mass in consideration of the use of a magnesium alloy having a higher specific strength. A high magnesium alloy, such as AZ61 or AZ61A, is preferably formed by forming a chemical conversion coating on the surface of the extruded, rolled, or drawn magnesium alloy product.
本発明においてはマグネシウム合金に対して無機酸あるいは有機酸溶液によるエッチング処理を実施することが必須であるが、押し出し加工、圧延加工、あるいは引き抜き加工したマグネシウム合金製品等の表面には切削油、離型剤等が残っているので、エッチング処理に先立ってマグネシウム合金をリン酸塩水溶液で脱脂処理することが好ましい。リン酸塩水溶液で脱脂処理することにより切削油は除去でき、また離型剤は軟化して除去しやすくなる。 In the present invention, it is indispensable to carry out an etching treatment with an inorganic acid or an organic acid solution on the magnesium alloy, but the surface of the extruded, rolled, or drawn magnesium alloy product or the like has a cutting oil and a release agent. Since the mold agent and the like remain, it is preferable to degrease the magnesium alloy with an aqueous phosphate solution prior to the etching treatment. By degreasing with an aqueous phosphate solution, the cutting oil can be removed, and the release agent is softened and easily removed.
本発明においてエッチング処理に用いられる無機酸及び有機酸として、リン酸、酸性フッ化アンモニウム、硝酸、塩酸、蓚酸、硫酸、クエン酸、酒石酸等の水溶液を挙げることができる。このような酸を用いたエッチング処理により離型剤やマグネシウム合金素材表面に析出した合金不均一層を溶解除去することができる。 Examples of the inorganic acid and organic acid used for the etching treatment in the present invention include aqueous solutions of phosphoric acid, acidic ammonium fluoride, nitric acid, hydrochloric acid, oxalic acid, sulfuric acid, citric acid, tartaric acid, and the like. The alloy heterogeneous layer deposited on the surface of the mold release agent or the magnesium alloy material can be dissolved and removed by etching using such an acid.
このエッチング処理においてはマグネシウム合金表面からの溶出量を５ｇ／ｍ2以下に制御する必要がある。溶出量が５ｇ／ｍ2を超えるとマグネシウム合金表面が過剰に荒れた状態となる傾向があり、このような過剰に荒れた状態の表面に皮膜形成処理を実施すると化成処理皮膜が過剰に析出し、皮膜量が過大となるばかりでなく、過剰析出成分が微粉となって表面に残留した状態となる傾向がある。また、そのような化成処理皮膜表面に塗装を行った場合には、塗膜種によっては密着性、特に耐水密着性が著しく低下する。 In this etching process, it is necessary to control the elution amount from the surface of the magnesium alloy to 5 g / m 2 or less. When the amount of elution exceeds 5 g / m 2 , the magnesium alloy surface tends to be excessively roughened, and when a film forming treatment is performed on such an excessively rough surface, the chemical conversion film is excessively deposited. In addition to the excessive amount of the coating, there is a tendency that the excessively precipitated components become fine powder and remain on the surface. Moreover, when coating is performed on the surface of such a chemical conversion treatment film, the adhesion, particularly the water-resistant adhesion, is remarkably lowered depending on the type of coating film.
従って、無機酸あるいは有機酸によるエッチング処理工程を上記した作用に適う処方で実施することが必要である。このエッチング処理における好ましい処方は、例えば、リン酸溶液については０.１〜１.５質量％の濃度とし、常温〜７０℃の温度で１０秒間〜１０分間の浸漬処理を行うことである。このリン酸の濃度が０.１質量％未満であったり、処理時間が１０秒未満であるとエッチング処理が不完全となる傾向がある。エッチング処理が不完全であると、マグネシウム合金表面に残留した潤滑油等の成分の除去が不十分で、エッチング処理後に形成される化成処理皮膜についての裸耐食性や塗膜密着性等について不良の原因となる。 Therefore, it is necessary to carry out the etching treatment step using an inorganic acid or an organic acid with a formulation suitable for the above-described action. A preferable prescription in this etching treatment is, for example, a phosphoric acid solution having a concentration of 0.1 to 1.5% by mass and an immersion treatment for 10 seconds to 10 minutes at a temperature of room temperature to 70 ° C. If the concentration of phosphoric acid is less than 0.1% by mass or the treatment time is less than 10 seconds, the etching treatment tends to be incomplete. If the etching process is incomplete, the removal of components such as lubricating oil remaining on the surface of the magnesium alloy is insufficient, and the cause of defects in the bare corrosion resistance, coating adhesion, etc. of the chemical conversion film formed after the etching process It becomes.
一般論として、リン酸溶液の濃度が高ければ、比較的低い温度で且つ比較的短時間で所望程度のエッチング処理が完了し、エッチング液の温度が高ければ、比較的低いリン酸溶液濃度で且つ比較的短時間で所望程度のエッチング処理が完了し、また、処理時間を長くすれば、比較的低いリン酸溶液濃度で且つ比較的低い温度で所望程度のエッチング処理が完了する。なお、このリン酸の濃度が１０質量％を超えたり、処理時間が１０分間を超えると、エッチングが過度に進んでマグネシウム合金表面が過剰に荒れた状態となる傾向があり、前記したような欠陥に繋がる。 In general, if the concentration of the phosphoric acid solution is high, the desired etching process is completed at a relatively low temperature and in a relatively short time, and if the temperature of the etching solution is high, the concentration of the phosphoric acid solution is low and The desired etching process is completed in a relatively short time. If the processing time is increased, the desired etching process is completed at a relatively low phosphoric acid solution concentration and at a relatively low temperature. In addition, when the concentration of this phosphoric acid exceeds 10% by mass or the treatment time exceeds 10 minutes, there is a tendency that etching proceeds excessively and the surface of the magnesium alloy becomes excessively rough, and the defects as described above. It leads to.
なお、酸を用いたエッチング処理の際にスマットが生じることがあり、その場合には高アルカリ水溶液で処理してスマットを溶解除去し、不動態化膜を生成させることが好ましい。 Note that smut may be generated during the etching process using an acid. In such a case, it is preferable that the smut be dissolved and removed by treatment with a highly alkaline aqueous solution to form a passivated film.
本発明においては、エッチング処理後に、そのマグネシウム合金をカルシウムイオン、マンガンイオン及びリン酸イオンを含有する化成処理浴中に浸漬して化成処理を行う。なお、この化成処理浴は所望により酸化促進剤を含有することができ、酸化促進剤を含有する方がより好ましい。 In the present invention, after the etching treatment, the magnesium alloy is subjected to chemical conversion treatment by immersing it in a chemical conversion treatment bath containing calcium ions, manganese ions and phosphate ions. In addition, this chemical conversion treatment bath can contain an oxidation accelerator if desired, and it is more preferable to contain an oxidation accelerator.
この化成処理浴に用いるカルシウムイオン源として、硝酸カルシウム、亜硝酸カルシウム、チオ硫酸カルシウム、リン酸二水素カルシウム等の一種又は二種以上を配合することができる。また、マンガンイオン源として、炭酸マンガン、硝酸マンガン、リン酸水素マンガン、重リン酸マンガン、ホウフッ化マンガン等の一種又は二種以上を配合することができる。また、リン酸イオン源として、オルソリン酸、縮合リン酸、亜リン酸、次亜リン酸等の一種又は二種以上を配合することができる。 As a calcium ion source used in this chemical conversion treatment bath, one or more of calcium nitrate, calcium nitrite, calcium thiosulfate, calcium dihydrogen phosphate and the like can be blended. Moreover, 1 type (s) or 2 or more types, such as manganese carbonate, manganese nitrate, manganese hydrogen phosphate, manganese biphosphate, manganese borofluoride, can be mix | blended as a manganese ion source. Moreover, 1 type, or 2 or more types, such as orthophosphoric acid, condensed phosphoric acid, phosphorous acid, hypophosphorous acid, can be mix | blended as a phosphate ion source.
また、酸化促進剤として、塩素酸ナトリウム、次亜塩素酸ナトリウム等を用いることができる。この酸化促進剤が存在することにより、化成処理時に、マグネシウム合金と上記の各成分イオンとの反応性を高めて、裸耐食性等が良好な化成処理皮膜を一層好都合に形成することができる。また、この酸化促進剤の好ましい配合量は、上記の性能の化成処理皮膜を安定的に得るために、０.０２〜２ｇ／Ｌの範囲の量である。 Moreover, sodium chlorate, sodium hypochlorite, etc. can be used as an oxidation accelerator. The presence of this oxidation accelerator can increase the reactivity between the magnesium alloy and each of the above-mentioned component ions during the chemical conversion treatment, and more conveniently form a chemical conversion treatment film having good bare corrosion resistance and the like. Moreover, the preferable compounding quantity of this oxidation accelerator is the quantity of the range of 0.02-2g / L, in order to obtain the chemical conversion treatment film of said performance stably.
本発明においては、上記の化成処理浴を用いた化成処理で、マグネシウム合金表面との反応により適度な膜厚で、緻密で、且つ所定量のカルシウム、マンガン及びリンを含むリン酸カルシウム−リン酸マンガンの複合化成処理皮膜が生成し、一定の裸耐食性、塗膜密着性及び塗膜耐食性が達成される。 In the present invention, in the chemical conversion treatment using the above chemical conversion treatment bath, calcium phosphate-manganese phosphate containing a predetermined amount of calcium, manganese, and phosphorus having an appropriate film thickness and a precise thickness by reaction with the magnesium alloy surface. A composite chemical conversion film is formed, and certain bare corrosion resistance, coating film adhesion and coating film corrosion resistance are achieved.
このマグネシウム合金の表面に形成する化成処理皮膜の付着量がＣａ、Ｍｎ及びＰの３元素の合計量で５５０〜１０００ｍｇ／ｍ2となるように化成処理することが好ましい。化成処理皮膜の付着量がＣａ、Ｍｎ及びＰの３元素の合計量で５５０ｍｇ／ｍ2未満になると、その化成処理皮膜上に塗膜を形成しても塗膜の耐食性が不十分となる傾向がある。逆に、化成処理皮膜の付着量がＣａ、Ｍｎ及びＰの３元素の合計量で１０００ｍｇ／ｍ2を超えると、化成処理皮膜の膜厚が厚くなり、化成処理皮膜に対する塗膜の密着性が低下する傾向があり、また、化成処理時間が長くなり、実用的ではない。 The chemical conversion treatment is preferably performed so that the amount of the chemical conversion film formed on the surface of the magnesium alloy is 550 to 1000 mg / m 2 in terms of the total amount of the three elements Ca, Mn and P. When the adhesion amount of the chemical conversion coating film is less than 550 mg / m 2 in terms of the total amount of the three elements Ca, Mn and P, the corrosion resistance of the coating film tends to be insufficient even if a coating film is formed on the chemical conversion coating film. There is. On the contrary, when the adhesion amount of the chemical conversion coating exceeds 1000 mg / m 2 in terms of the total amount of the three elements of Ca, Mn and P, the chemical conversion coating becomes thick, and the adhesion of the coating to the chemical conversion coating is increased. It tends to decrease, and the chemical conversion treatment time becomes long, which is not practical.
また、化成処理皮膜中のカルシウムとリンは化成処理皮膜の裸耐食性の向上に寄与し、またマンガンは塗膜密着性の向上に寄与するものと考えられ、優れた化成処理皮膜を安定的に得るために、このマグネシウム合金の表面に形成する化成処理皮膜中のＣａ、Ｍｎ及びＰの質量比がＭｎ：Ｃａ：Ｐ＝１：１〜２：３.５〜５となるように化成処理することが好ましい。化成処理皮膜中のＣａ、Ｍｎ及びＰの質量比が上記の範囲から外れる場合には化成処理皮膜の裸耐食性、塗膜密着性の何れかが不十分となる傾向がある。 In addition, calcium and phosphorus in the chemical conversion coating contribute to the improvement of the bare corrosion resistance of the chemical conversion coating, and manganese is considered to contribute to the improvement of the adhesion of the coating, so that an excellent chemical conversion coating can be stably obtained. Therefore, the chemical conversion treatment is performed so that the mass ratio of Ca, Mn and P in the chemical conversion coating formed on the surface of the magnesium alloy is Mn: Ca: P = 1: 1 to 2: 3.5-5. Is preferred. When the mass ratio of Ca, Mn and P in the chemical conversion coating is out of the above range, either the naked corrosion resistance or the coating adhesion of the chemical conversion coating tends to be insufficient.
上記のような化成処理皮膜を得るためには、化成処理浴中の上記の各成分について、カルシウムイオンが０.３〜１０ｇ／Ｌ、マンガンイオンが０.１〜５ｇ／Ｌ及びリン酸イオンが１〜３０ｇ／Ｌの濃度となるように配合することが好ましい。これらの各成分について、このような濃度範囲の配合量にすることにより、マグネシウム合金の表面に裸耐食性や塗膜密着性等の良好な化成処理皮膜を安定的かつ経済的に形成することができる。 In order to obtain the chemical conversion coating as described above, for each of the above components in the chemical conversion bath, the calcium ion is 0.3 to 10 g / L, the manganese ion is 0.1 to 5 g / L, and the phosphate ion is It is preferable to mix | blend so that it may become a density | concentration of 1-30 g / L. About these each component, by making it the compounding quantity of such a concentration range, favorable chemical conversion treatment films, such as bare corrosion resistance and coating film adhesion, can be stably and economically formed on the surface of a magnesium alloy. .
なお、化成処理浴中のカルシウムイオンが不足する場合には、得られる化成処理皮膜の裸耐食性や塗膜密着性等が低下する傾向があり、また、マンガンイオンやリン酸イオンが不足する場合には、塗膜密着性の低下に加えて、酸化促進剤からの塩素イオンに起因して白錆が発生する原因となる傾向がある。 In addition, when the calcium ion in the chemical conversion treatment bath is insufficient, there is a tendency that the naked corrosion resistance, coating film adhesion, etc. of the chemical conversion treatment film to be obtained are reduced, and when the manganese ion or phosphate ion is insufficient. Tends to cause white rust due to chlorine ions from the oxidation accelerator, in addition to a decrease in coating film adhesion.
また、この化成処理浴はｐＨ１.０〜３.０に調整されていることが好ましい。このｐＨ値が１.０未満であると、化成処理時に生じるエッチング量が過大となって、マグネシウム合金製品の寸法精度上の問題が生じると共に、裸耐食性の低下をきたす傾向がある。また、このｐＨ値が３.０を超えると、化成処理皮膜の裸耐食性等の性能の低下をきたす傾向がある。 Moreover, it is preferable that this chemical conversion treatment bath is adjusted to pH 1.0-3.0. If this pH value is less than 1.0, the etching amount generated during the chemical conversion treatment becomes excessive, which causes a problem in dimensional accuracy of the magnesium alloy product and tends to lower the bare corrosion resistance. Moreover, when this pH value exceeds 3.0, there exists a tendency for performance, such as a bare corrosion resistance, of a chemical conversion treatment film to fall.
また、この化成処理浴は３０〜７５℃の範囲の温度に維持されていることが好ましい。この化成処理浴温度が３０℃未満であると、化成処理皮膜の形成に長時間を要し、化成処理皮膜の裸耐食性等について不良の原因となったりする傾向がある。この化成処理浴温度が７５℃を超えると、化成処理皮膜の裸耐食性等の性能が低下する傾向がある。 Moreover, it is preferable that this chemical conversion treatment bath is maintained at the temperature of the range of 30-75 degreeC. When this chemical conversion bath temperature is less than 30 ° C., it takes a long time to form the chemical conversion coating, and there is a tendency to cause defects in the naked corrosion resistance of the chemical conversion coating. When this chemical conversion treatment bath temperature exceeds 75 degreeC, there exists a tendency for performance, such as bare corrosion resistance, of a chemical conversion treatment film to fall.
この化成処理浴による化成処理のための時間は化成処理浴温度と相関関係にある。即ち、化成処理浴温度が５０℃未満である場合には３〜２０分間浸漬することが好ましく、また化成処理浴温度が５０℃以上の場合には０.５〜１０分間浸漬することが好ましい。化成処理浴温度が５０℃未満で浸漬時間が短いと、化成処理皮膜の形成量が不十分となる。また化成処理浴温度が５０℃以上で浸漬時間が長いと、形成された化成処理皮膜の再溶出が生じて裸耐食性等の性能の低下をきたすことがある。 The time for the chemical conversion treatment in this chemical conversion bath has a correlation with the chemical conversion bath temperature. That is, when the chemical conversion bath temperature is less than 50 ° C., it is preferable to immerse for 3 to 20 minutes, and when the chemical conversion bath temperature is 50 ° C. or higher, it is preferable to immerse for 0.5 to 10 minutes. When the chemical conversion bath temperature is less than 50 ° C. and the immersion time is short, the amount of chemical conversion coating film formed becomes insufficient. Moreover, when the chemical conversion bath temperature is 50 ° C. or higher and the immersion time is long, the formed chemical conversion coating film may be re-eluted and performance such as bare corrosion resistance may be deteriorated.
本発明は上記したような各処理工程を含む化成処理皮膜の形成方法であり、上記した各処理工程に引き続いてそれぞれ水洗工程を含ませることが好ましく、また、化成処理に引き続いて、一般的な化成処理皮膜の形成方法に従って、水洗し、乾燥させる。これらの諸工程をフローチャート式に記載すると次の通りである：脱脂→水洗→エッチング→水洗→スマット除去→水洗→化成処理（化成処理皮膜形成）→水洗→脱イオン水で水洗→水切り乾燥。 The present invention is a method of forming a chemical conversion treatment film including each treatment step as described above, and preferably includes a water washing step subsequent to each treatment step described above, and following a chemical conversion treatment, According to the formation method of the chemical conversion film, it is washed with water and dried. These steps are described in a flow chart as follows: degreasing → washing → etching → washing → smut removal → water washing → chemical conversion treatment (formation of chemical conversion film) → water washing → water washing with deionized water → draining and drying.
その後、塗装処理を施すことができる。この塗装処理として、吹き付け塗装や電着塗装等の方法によりエポキシ樹脂等の塗料を下塗りし、更にこれにメラミン樹脂等の塗料を上塗りすることができる。その他にも、各種樹脂による粉体塗料を静電塗装することもできる。 Thereafter, a coating process can be performed. As this coating treatment, a paint such as an epoxy resin can be undercoated by a method such as spray coating or electrodeposition coating, and a paint such as a melamine resin can be further applied thereon. In addition, it is possible to electrostatically paint powder coatings made of various resins.
以下に、実施例及び比較例に基づいて本発明を更に具体的に説明する。 Hereinafter, the present invention will be described more specifically based on examples and comparative examples.
実施例１〜３及び比較例１〜５
処理対象部材として、ＡＳＴＭ ＡＺ６１のマグネシウム合金圧延部材及びＡＺ３１Ｂのマグネシウム合金押出し部材からそれぞれ作製した２ｍｍ×５０ｍｍ×１５０ｍｍの部材を用いた。脱脂剤として濃度３質量％の縮合リン酸塩水溶液を用い、その液温を６０℃に保持し、その中に上記の各々の部材を１分間浸漬して脱脂処理し、その後水洗した。
Examples 1-3 and Comparative Examples 1-5
2 mm × 50 mm × 150 mm members respectively produced from ASTM AZ61 magnesium alloy rolled members and AZ31B magnesium alloy extruded members were used as the processing target members. A condensed phosphate aqueous solution having a concentration of 3% by mass was used as a degreasing agent, the temperature of the solution was maintained at 60 ° C., each of the above members was immersed for 1 minute for degreasing treatment, and then washed with water.
エッチング剤としてグランダファイナーＭＧ１０４Ｓ（ミリオン化学株式会社製商品名：リン酸３０〜４０質量％、界面活性剤０.１質量％未満、残部水）、又はクエン酸水溶液を第１表又は第２表に示す酸濃度（質量％）（即ち、グランダファイナーＭＧ１０４Ｓの場合にはリン酸濃度、クエン酸水溶液の場合にはクエン酸濃度）で用い、第１表又は第２表に示す液温度に保持し、その中に上記の脱脂した部材を第１表又は第２表に示す時間浸漬してエッチング処理し、その後水洗した。その後、このエッチング処理した部材を、液温６０℃に保持した水酸化アルミニウム水溶液中に７分間浸漬して処理し、その後水洗した。 As an etchant, Grandafiner MG104S (Million Chemical Co., Ltd., trade name: phosphoric acid 30 to 40% by mass, surfactant less than 0.1% by mass, remaining water), or citric acid aqueous solution in Table 1 or Table 2 Used at the indicated acid concentration (mass%) (that is, phosphoric acid concentration in the case of Grandafiner MG104S, citric acid concentration in the case of citric acid aqueous solution), and held at the liquid temperature shown in Table 1 or Table 2, The degreased member described above was immersed in the time shown in Table 1 or Table 2 for etching treatment, and then washed with water. Thereafter, the etched member was immersed in an aluminum hydroxide aqueous solution maintained at a liquid temperature of 60 ° C. for 7 minutes and then washed with water.
化成処理浴としてグランダーＭＣ−１０００（ミリオン化学株式会社製商品名：濃度２.５質量％で用いる場合には、カルシウムイオン１.０ｇ／Ｌ、マンガンイオン０.３５ｇ／Ｌ、リン酸イオン５.８ｇ／Ｌ及び塩素酸ナトリウム（酸化促進剤）０.１５ｇ／Ｌを含有する水溶液となり、濃度５質量％及び濃度７.５質量％で用いる場合には各成分をそれぞれ２倍、３倍の量で含有する水溶液となる）を用い、第１表又は第２表に示す温度に保持してその中に上記のように処理した部材を第１表又は第２表に示す時間浸漬して化成処理し、水洗し、更に脱イオン水で水洗し、その後乾燥させた。 Grander MC-1000 (trade name: manufactured by Million Chemical Co., Ltd. as a chemical conversion bath: when used at a concentration of 2.5% by mass, calcium ion 1.0 g / L, manganese ion 0.35 g / L, phosphate ion 5. 8g / L and aqueous solution containing 0.15g / L of sodium chlorate (oxidation accelerator). When used at a concentration of 5% by mass and 7.5% by mass, each component is doubled and tripled. And the components treated as described above while maintaining the temperature shown in Table 1 or Table 2 are immersed in the chemical conversion treatment in the time shown in Table 1 or Table 2. And then washed with deionized water and then dried.
上記のようにして得られた各々の化成処理皮膜付き部材の表面にエアースプレー法によりエポキシ樹脂系塗料（大日本塗料株式会社製商品名：ＭＧ−ＰＲ−Ｅ）を膜厚２０μｍとなるように塗布し、２０分間静置した後、更にエアースプレー法によりウェットオンウェットでアクリル−メラミン樹脂系塗料（大日本塗料株式会社製商品名：ＭＧ−トップ）を膜厚２０μｍとなるように塗布し、これを１８０℃で２０分間焼付処理した。 An epoxy resin-based paint (trade name: MG-PR-E, manufactured by Dainippon Paint Co., Ltd.) is formed on the surface of each member with a chemical conversion treatment film obtained as described above by an air spray method so that the film thickness becomes 20 μm. After applying and allowing to stand for 20 minutes, an acrylic-melamine resin-based paint (trade name: MG-Top, manufactured by Dainippon Paint Co., Ltd.) was applied by wet-on-wet by an air spray method to a film thickness of 20 μm, This was baked at 180 ° C. for 20 minutes.
上記のようにして得られた各々の塗膜について、下記の塗膜性能を下記の方法で評価した。 About each coating film obtained by making it above, the following coating film performance was evaluated by the following method.
イ）塗膜密着性
ＪＩＳ Ｋ ５４００ ８.５.２の碁盤目テープ法に準拠して、塩水噴霧試験１０００時間後、塗膜にナイフで碁盤目模様を描き、１００個の部分に区分した後、粘着テープにより塗膜の剥離を試みた。実施例１〜３及び比較例１〜５の全てにおいて塗膜の剥離は全く認められなかった。
B) Coating film adhesion In accordance with the cross-cut tape method of JIS K 5400 8.5.2, after 1000 hours of salt spray test, a cross-cut pattern is drawn on the coating film with a knife and divided into 100 parts. An attempt was made to peel off the coating film using an adhesive tape. In all of Examples 1 to 3 and Comparative Examples 1 to 5, no peeling of the coating film was observed.
ロ）耐塩水噴霧性
塗膜表面にナイフでストレートカットを入れ、ＪＩＳ Ｚ ２３７１に準拠して塩水噴霧試験（ＳＳＴ）を１５００時間実施した。５００時間後、１０００時間後及び１５００時間後のストレートカット部分の塗膜の最大剥離幅（ｍｍ）を測定した。それらの結果は第１表又は第２表に示す通りであった。
B) Salt spray resistance A straight cut was made on the surface of the coating film with a knife, and a salt spray test (SST) was carried out for 1500 hours in accordance with JIS Z 2371. The maximum peeling width (mm) of the coating film of the straight cut portion after 500 hours, 1000 hours and 1500 hours was measured. The results were as shown in Table 1 or Table 2.
第１表に示すデータから明らかなように、本発明のマグネシウム合金の化成処理皮膜の形成方法である実施例１〜３においては、塩水噴霧試験１０００時間後における最大剥離幅は０〜０.５ｍｍであり、１５００時間後においても最大剥離幅は１ｍｍであった。 As is apparent from the data shown in Table 1, in Examples 1 to 3, which are the methods for forming the chemical conversion film of the magnesium alloy of the present invention, the maximum peel width after 1000 hours of the salt spray test is 0 to 0.5 mm. Even after 1500 hours, the maximum peel width was 1 mm.
これに対して、特開２００３−２８６５８２号公報に記載された発明の好ましい範囲である請求項３及び４に記載された発明の範囲内で且つ特開２００３−２８６５８２号公報に記載された実施例１〜５の範囲内に入る上記の比較例１、２及び４においては、塩水噴霧試験１０００時間後における最大剥離幅は２〜５ｍｍであり、１５００時間後における最大剥離幅は３〜１０ｍｍであった。また、特開２００３−２８６５８２号公報に記載された発明の好ましい範囲である請求項３及び４に記載された発明の範囲内であるがＣａ、Ｍｎ及びＰの３元素の合計量を特開２００３−２８６５８２号公報に記載された実施例１〜５の範囲（１９６.４〜３３６.３ｍｇ／ｍ2）外の４８７.９ｍｇ／ｍ2に増量した上記の比較例３においては、塩水噴霧試験１５００時間後における最大剥離幅は３ｍｍであり、本発明の場合より劣っていた。更に、化成処理皮膜の付着量がＣａ、Ｍｎ及びＰの３元素の合計量が９３５.３ｍｇ／ｍ2である比較例５においては、本発明の範囲外のＡＺ３１Ｂのマグネシウム合金押出し部材を用いているので、塩水噴霧試験１０００時間後における最大剥離幅は４ｍｍであり、１５００時間後における最大剥離幅は１０ｍｍであった。
On the other hand, the preferred embodiments of the invention described in Japanese Patent Laid-Open No. 2003-286582 are examples within the scope of the invention described in Claims 3 and 4 and described in Japanese Patent Laid-Open No. 2003-286582. In Comparative Examples 1, 2, and 4 that fall within the range of 1 to 5, the maximum peel width after 1000 hours of the salt spray test is 2 to 5 mm, and the maximum peel width after 1500 hours is 3 to 10 mm. It was. Further, the total amount of the three elements Ca, Mn and P is within the scope of the invention described in claims 3 and 4 which is a preferred range of the invention described in JP-A-2003-286582. In Comparative Example 3 above, which was increased to 487.9 mg / m 2 outside the range of Examples 1 to 5 (196.4 to 336.3 mg / m 2 ) described in Japanese Patent No. -286582, the salt spray test 1500 The maximum peel width after 3 hours was 3 mm, which was inferior to that of the present invention. Furthermore, in Comparative Example 5 in which the total amount of the three elements Ca, Mn, and P is 935.3 mg / m 2 , the AZ31B magnesium alloy extruded member outside the scope of the present invention is used. Therefore, the maximum peel width after 1000 hours of the salt spray test was 4 mm, and the maximum peel width after 1500 hours was 10 mm.
Claims (3)
The method for forming a chemical conversion treatment film of a magnesium alloy according to claim 1 or 2, wherein the magnesium alloy is an extruded product or a rolled product.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2004092941A JP2005281717A (en) | 2004-03-26 | 2004-03-26 | Method for forming chemical conversion-treated film of magnesium alloy |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2004092941A JP2005281717A (en) | 2004-03-26 | 2004-03-26 | Method for forming chemical conversion-treated film of magnesium alloy |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2005281717A true JP2005281717A (en) | 2005-10-13 |
Family
ID=35180440
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2004092941A Pending JP2005281717A (en) | 2004-03-26 | 2004-03-26 | Method for forming chemical conversion-treated film of magnesium alloy |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2005281717A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2008029497A1 (en) * | 2006-09-08 | 2008-03-13 | Sumitomo Electric Industries, Ltd. | Magnesium alloy member and method for producing the same |
| WO2010087456A1 (en) | 2009-02-02 | 2010-08-05 | 独立行政法人物質・材料研究機構 | Mg-BASED STRUCTURED MEMBER |
| WO2011071023A1 (en) * | 2009-12-11 | 2011-06-16 | 住友電気工業株式会社 | Magnesium alloy member |
| JP2012097340A (en) * | 2010-11-04 | 2012-05-24 | Mitsui Mining & Smelting Co Ltd | Magnesium alloy surface treatment method |
| KR101167155B1 (en) | 2004-12-24 | 2012-07-24 | 재단법인 포항산업과학연구원 | Method for improving the corrosion resistance of magnesium melting crucible |
-
2004
- 2004-03-26 JP JP2004092941A patent/JP2005281717A/en active Pending
Cited By (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101167155B1 (en) | 2004-12-24 | 2012-07-24 | 재단법인 포항산업과학연구원 | Method for improving the corrosion resistance of magnesium melting crucible |
| TWI406719B (en) * | 2006-09-08 | 2013-09-01 | Sumitomo Electric Industries | Magnesium alloy member and method of manufacturing the same |
| AU2007292778B2 (en) * | 2006-09-08 | 2011-01-06 | Sumitomo Electric Industries, Ltd. | Magnesium alloy member and method for producing the same |
| JP5201535B2 (en) * | 2006-09-08 | 2013-06-05 | 住友電気工業株式会社 | Magnesium alloy member and manufacturing method thereof |
| US8501301B2 (en) | 2006-09-08 | 2013-08-06 | Sumitomo Electric Industries, Ltd. | Magnesium alloy member and method of manufacturing the same |
| WO2008029497A1 (en) * | 2006-09-08 | 2008-03-13 | Sumitomo Electric Industries, Ltd. | Magnesium alloy member and method for producing the same |
| KR101412245B1 (en) | 2006-09-08 | 2014-06-25 | 스미토모덴키고교가부시키가이샤 | Magnesium alloy member and method of manufacturing the same |
| CN102301034A (en) * | 2009-02-02 | 2011-12-28 | 独立行政法人物质·材料研究机构 | Mg-based structured member |
| WO2010087456A1 (en) | 2009-02-02 | 2010-08-05 | 独立行政法人物質・材料研究機構 | Mg-BASED STRUCTURED MEMBER |
| CN102301034B (en) * | 2009-02-02 | 2013-09-18 | 独立行政法人物质·材料研究机构 | Mg-based structured member |
| WO2011071023A1 (en) * | 2009-12-11 | 2011-06-16 | 住友電気工業株式会社 | Magnesium alloy member |
| US9103010B2 (en) | 2009-12-11 | 2015-08-11 | Sumitomo Electric Industries, Ltd. | Magnesium alloy structural member |
| JP2012097340A (en) * | 2010-11-04 | 2012-05-24 | Mitsui Mining & Smelting Co Ltd | Magnesium alloy surface treatment method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP1433876B1 (en) | Chemical conversion coating agent and surface-treated metal | |
| JP4276530B2 (en) | Chemical conversion treatment agent and surface treatment metal | |
| WO2001075190A1 (en) | Surface treatment method for magnesium alloys and magnesium alloy members thus treated | |
| JP6083020B2 (en) | Surface treatment method of magnesium or magnesium alloy, acid detergent and chemical conversion treatment agent, and chemical conversion treatment structure of magnesium or magnesium alloy | |
| JP4446230B2 (en) | Trivalent chromate solution for aluminum or aluminum alloy and method for forming corrosion-resistant film on aluminum or aluminum alloy surface using the same | |
| JP2010106334A (en) | Chemical conversion treatment liquid and chemical conversion treatment method for metal material | |
| JP3325366B2 (en) | Chemical conversion treatment liquid composition for magnesium-containing metal, chemical conversion treatment method, and chemical conversion-treated material | |
| TW554020B (en) | Magnesium conversion coating composition and method of using same | |
| NZ273541A (en) | Cleaning metal surfaces by treatment with alkaline cleaning solution and then with rare earth ion-containing, acidic solution; metal surfaces coated with rare earth (compounds) | |
| JP2006316334A (en) | Non-chromate chemical conversion treatment liquid for aluminum alloy, and aluminum alloy chemical conversion treatment method by the same | |
| US20020174915A1 (en) | Chemical conversion reagent for magnesium alloy, surface-treating method, and magnesium alloy substrate | |
| JP2022125057A (en) | Base material having at least all or part of surface made of metal material, base material having pores on surface of metal material, and composite of base material-resin cured product comprising base material and resin cured product | |
| JP3845328B2 (en) | Method for forming a chemical conversion coating on magnesium alloy | |
| JP3682622B2 (en) | Surface treatment agent, surface treatment method, and surface-treated product | |
| JP2000096255A (en) | Body of magnesium-containing metal treated with low electric resistance coating and its surface treatment | |
| JP2005281717A (en) | Method for forming chemical conversion-treated film of magnesium alloy | |
| JP2003171776A (en) | Surface treatment method for lithium based magnesium alloy material | |
| KR100855358B1 (en) | Chemical Coating Solutions for Magnesium Alloys, Environmental-affinitive Surface Treating Methods Using the Same, and Magnesium Alloy Substrates thereby | |
| WO2012109339A2 (en) | Processes and compositions for improving corrosion performance of zirconium oxide pretreated zinc surfaces | |
| JP3286583B2 (en) | Chemical conversion treatment composition for magnesium-containing metal, surface treatment method and surface treatment product | |
| JP2004232047A (en) | Treatment agent for forming highly corrosion resistant chromium-free chemical conversion film on aluminum and aluminum alloy, method of forming the chemical conversion film, and aluminum and aluminum alloy with the chemical conversion film formed | |
| JP2006131971A (en) | Cold rolled steel sheet having excellent phosphate treatability and salt warm water resistance after coating | |
| JP3190188B2 (en) | Zinc-containing metal-coated steel sheet composite with excellent high-speed press formability | |
| JP4747019B2 (en) | Chemical conversion treatment method and chemical treatment of magnesium alloy | |
| JP2002327280A (en) | Metal surface treatment agent |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A977 | Report on retrieval |
Effective date: 20060501 Free format text: JAPANESE INTERMEDIATE CODE: A971007 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20060517 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20060713 |
|
| A02 | Decision of refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A02 Effective date: 20060823 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A821 Effective date: 20060921 |