EP0573585B1 - Zweistufiges chemisches bzw elektrochemisches verfahren zur beschichtung von magnesium - Google Patents

Zweistufiges chemisches bzw elektrochemisches verfahren zur beschichtung von magnesium Download PDF

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EP0573585B1
EP0573585B1 EP92907909A EP92907909A EP0573585B1 EP 0573585 B1 EP0573585 B1 EP 0573585B1 EP 92907909 A EP92907909 A EP 92907909A EP 92907909 A EP92907909 A EP 92907909A EP 0573585 B1 EP0573585 B1 EP 0573585B1
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article
magnesium
fluoride
coating
silicon oxide
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EP0573585A1 (de
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Duane E. Bartak
Brian E. Lemieux
Earl R. Woolsey
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Technology Applications Group Inc
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Technology Applications Group Inc
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    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D11/00—Electrolytic coating by surface reaction, i.e. forming conversion layers
    • C25D11/02—Anodisation
    • C25D11/30—Anodisation of magnesium or alloys based thereon

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  • the invention relates to a process for forming an inorganic coating on a magnesium alloy and to a product formed by this process.
  • the invention relates to a method comprising pretreating an article comprising a magnesium alloy in a chemical bath at a neutral pH followed by an electrolytically coating the pretreated article in an aqueous solution.
  • Magnesium is generally alloyed with any of aluminum, manganese, thorium, lithium, tin, zirconium, zinc, rare earth metals or other alloys to increase its structural stability. Such magnesium alloys are often used where a high strength to weight ratio is required. The appropriate magnesium alloy can also offer the highest strength to weight ratio of the ultra light metals at elevated temperatures. Further, alloys with rare earth or thorium can retain significant strength up to temperatures of 315°C and higher. Structural magnesium alloys may be assembled in many of the conventional manners including riveting and bolting, arc and electric resistance welding, braising, soldering and adhesive bonding.
  • the magnesium-containing articles have uses in the aircraft and aerospace industries, military equipment, electronics, automotive bodies and parts, hand tools and in materials handling. While magnesium and its alloys exhibit good stability in the presence of a number of chemical substances, there is a need to further protect the metal, especially in acidic environments and in salt water conditions. Therefore, especially in marine applications, it is necessary to provide a coating to protect the metal from corrosion.
  • coatings for magnesium There are many different types of coatings for magnesium which have been developed and used. The most common coatings are chemical treatments or conversion coatings which are used as a paint base and provide some corrosion protection. Both chemical and electrochemical methods are used for the conversion of magnesium surfaces. Chromate films are the most commonly used surface treatment for magnesium alloys. These films of hydrated, gel-like structures of polychromates provide a surface which is a good paint base but which provides limited corrosion protection.
  • Anodization of magnesium alloys is an alternative electrochemical approach to provide a protective coating.
  • At least two low voltage anodic processes, Dow 17 and HAE have been commercially employed.
  • the Dow 17 process utilizes potassium dichromate, a chromium (VI) compound, which is acutely toxic and strictly regulated.
  • the key ingredient in the HAE anodic coating is potassium permanganate, it is necessary to use a chromate sealant with this coating in order to obtain acceptable corrosion resistance.
  • chromium (VI) is necessary in the overall process in order to achieve a desirable corrosion resistant coating. This use of chromium (VI) means that waste disposal from these processes is a significant problem.
  • metallic and ceramic-like coatings have been developed. These coatings may be formed by electroless or electrochemical processes.
  • the electroless deposition of nickel on magnesium and magnesium alloys using chemical reducing agents in coating formulation is well known in the art.
  • this process also results in the creation of large quantities of hazardous heavy metal contaminated waste water which must be treated before it can be discharged.
  • Electrochemical coating processes can be used to produce both metallic and nonmetallic coatings. The metallic coating processes again suffer from the creation of heavy metal contaminated waste water.
  • Non-metallic coating processes have been developed, in part, to overcome problems involving the heavy metal contamination of waste water.
  • Kozak, U.S. Patent No. 4,184,926, discloses a two-step process for forming an anti-corrosive coating on magnesium and its alloys.
  • the first step is an acidic chemical pickling or treatment of the magnesium work piece using hydrofluoric acid at about room temperature to form a fluoro-magnesium layer on the metal surface.
  • the second step involves the electrochemical coating of the work piece in a solution comprising an alkali metal silicate and an alkali metal hydroxide.
  • a voltage potential from about 150-300 volts is applied across the electrodes, and a current density of about 50-200 mA/cm2 is maintained in the bath.
  • the first step of this process is a straight forward acid pickling step, while the second step proceeds in an electrochemical bath which contains no source of fluoride. Tests of this process indicate that there is a need for increased corrosion resistance and coating integrity.
  • U.S. Patent No. 4,620,904 discloses a one-step method of coating articles of magnesium using an electrolytic bath comprising an alkali metal silicate, an alkali metal hydroxide and a fluoride.
  • the bath is maintained at a temperature of about 5-70°C and a pH of about 12-14.
  • the electrochemical coating is carried out under a voltage potential from about 150-400 volts. Tests of this process also indicates that there remains a need for increased corrosion resistance.
  • the present invention is directed to a process for coating a magnesium-containing article.
  • the article is pretreated in an aqueous solution comprising 0.2 to 5 molar ammonium fluoride having a pH of 5 to 8 and a temperature of 40 to 100°C. This pretreatment step cleans the article and creates an ammonium fluoride-containing layer at the surface of the article to form a pretreated article.
  • the pretreated article is immersed in an aqueous electrolytic solution having a pH of at least 12.5 and which solution comprises 2 to 12 g/L of a aqueous soluble hydroxide, 2 to 15 g/L of a fluoride-containing composition selected from the group consisting of fluorides and fluorosilicates, and 5 to 30 g/L of a alkali metal silicate.
  • a voltage differential of at least 100 volts is established between an anode comprising the pretreated article and a cathode also in contact with the electrolytic solution to create a current density of 2 to 90 mA/cm2.
  • a silicon oxide-containing coating is formed on the magnesium-containing article.
  • magnesium-containing article means a metallic article having surfaces which are in whole or in part metallic magnesium per se or a magnesium alloy.
  • the article is formed of metallic magnesium or a magnesium alloy and comprises a significant amount of magnesium. More preferably, the article comprises a magnesium-rich alloy comprising at least about 50 wt-% magnesium, and most preferably, the article comprises at least about 80 wt-% magnesium.
  • Figure 1 illustrates the coated magnesium-containing article of the invention.
  • FIG. 2 is a block diagram of the present invention.
  • FIG. 3 is a diagram of the electrochemical process of the invention.
  • Figure 4 is a scanning electron photomicrograph of a cross section through the magnesium-containing substrate and a coating according to the invention.
  • FIG. 1 illustrates a cross section of a magnesium-containing article having been coated using the process of the present invention.
  • the magnesium-containing article 10 is shown with a first ammonium fluoride-containing layer 12 and a second ceramic-like layer 14.
  • the layers 12 and 14 combine to form a corrosion resistant coating on the surface of the magnesium-containing article.
  • Coatings include ceramic-like, silicon oxide containing coatings.
  • Figure 2 illustrates the steps used to produce these coated articles.
  • An untreated article 20 is first placed in a chemical bath 22 which cleans and forms an ammonium fluoride-containing layer on the article.
  • the article is treated in an electrochemical bath 24 resulting in the production of a coated article 26.
  • the chemical bath 22 comprises an aqueous ammonium fluoride solution.
  • the bath comprises 0.2 to 5 molar ammonium fluoride in water, preferably, 0.3 to 2.0 molar ammonium fluoride and, more preferably, about 0.5 to 1.2 molar ammonium fluoride.
  • the reaction conditions are indicated below in Table I.
  • Table I Condition According to the invention Preferred More Preferred pH 5-8 5-7 6-7 Temperature (°C) 40-100 55-90 70-85 Time (minutes) 15-60 30-45 30-40
  • the magnesium-containing article is maintained in the chemical bath for a time sufficient to clean impurities at the surface of the article and to form an ammonium fluoride-containing base layer on the magnesium-containing article.
  • Too brief a residence time in the chemical bath results in an insufficient fluoride containing base layer and/or insufficient cleaning of the magnesium-containing article. This will ultimately result in the reduced corrosion resistance of the coated article. Longer residence times tend to be uneconomical as the process time is increased with little improvement of the base layer.
  • This base layer is generally uniform in composition and thickness across the surface of the article and provides an excellent base upon which a second, ceramic-like layer may be deposited.
  • the thickness of this fluoride containing layer is about 1 to 2 ⁇ m.
  • the first chemical bath is beneficial as it provides a base layer which firmly bonds to and protects the substrate, which is compatible with the composition which will form the second layer and which adheres the second layer to the substrate.
  • the base layer comprises metal ammonium fluorides and oxofluorides which strongly adhere to the metallic substrate. It appears that the compatibility of these compounds with those of the second layer permits the deposition of silicon oxide, among other compounds, in a uniform manner without appreciable etching of the metal substrate.
  • This base layer provides some protection to the metallic substrate, but it does not provide the abrasion resistance and hardness that the complete, two-layered coating provides.
  • the silicon oxide-containing layer is applied to the metallic substrate without first depositing the base layer, the corrosion and abrasion resistance of the coating is reduced as the silicon oxide-containing layer does not adhere well to the substrate.
  • the pretreated article is preferably thoroughly washed with water to remove any unreacted ammonium fluoride. This cleaning prevents the contamination of the electrochemical bath 24.
  • the cleaned, pretreated article is then subjected to an electrochemical coating process shown in Figure 3.
  • the electrochemical bath 26 comprises an aqueous electrolytic solution comprising 2 to 12 g/L of a soluble hydroxide compound, 2 to 15 g/L of a soluble fluoride-containing compound selected from the group consisting of fluorides and fluorosilicates and 5 to 30 g/L of an alkali metal silicate.
  • Preferred hydroxides include alkali metal hydroxides. More preferably, the alkali metal is lithium, sodium or potassium, and most preferably, the hydroxide is potassium hydroxide.
  • the fluoride-containing compound may be a fluoride such as an alkali metal fluoride, such as lithium, sodium and potassium fluoride or an acid fluoride such as hydrogen fluoride or ammonium bifluoride. Fluorosilicates such as potassium fluorosilicate or sodium fluorosilicate may also be used.
  • the fluoride-containing compound comprises an alkali metal fluoride, an alkali metal fluorosilicate, hydrogen fluoride or mixtures thereof. Most preferably, the fluoride-containing compound comprises potassium fluoride.
  • the electrochemical bath also contains a silicate.
  • silicates include alkali metal silicates and/or alkali metal fluorosilicates. More preferably, the silicate comprises lithium, sodium or potassium silicate, and most preferably, the silicate is potassium silicate.
  • Table II Composition ranges for the aqueous electrolytic solution are shown below in Table II.
  • Table II Component According to the invention Preferred More Preferred Hydroxide 2-12 g/L 4-8 g/L 5-7 g/L Fluoride 2-15 g/L 3-10 g/L 8-10 g/L Silicate 5-30 g/L 10-25 g/L 15-20 g/L
  • the pretreated article 30 is immersed in the electrochemical bath 24 as an anode.
  • the vessel 32 which contains the electrochemical bath 24 may be used as the cathode.
  • the anode may be connected through a switch 34 to a rectifier 36 while the vessel 32 may be directly connected to the rectifier 36.
  • the rectifier 36 rectifies the voltage from a voltage source 38, to provide a direct current source to the electrochemical bath.
  • the rectifier 36 and switch 34 may be placed in communication with a microprocessor control 40 for purposes of controlling the electrochemical composition.
  • the rectifier provides a pulsed DC signal to drive the deposition process.
  • the conditions of the electrochemical deposition process are a pH of at least 12.5 and a current density of 2-90 mA/cm2, preferably they are as illustrated below in Table III.
  • Table III Component Preferred More Preferred Most Preferred pH 12.5-14 12.5-13 12.5-13 Temperature (°C) 5-30 10-25 10-20 Time (minutes) 5-80 15-60 20-30 Current Density (mA/cm2) 2-90 5-70 10-50
  • Coatings produced according to the above-described process are ceramic-like and have excellent corrosion and abrasion resistance and hardness characteristics. While not wishing to be held to this theory, it appears that these properties are the result of the morphology and adhesion of the coating on the metal substrate.
  • the preferred coatings comprise a mixture of fused silicon oxide and fluoride along with an alkali metal oxide.
  • the adhesion of the coating of the invention appears to perform considerably better than any known commercial coatings. This is a result of a coherent interface between the metal substrate and the coating.
  • coherent interface it is meant that the interface comprises a continuum of magnesium, magnesium oxides, magnesium oxofluorides, magnesium fluorides and silicon oxides.
  • the continuous interface is shown in Figure 4, a scanning electron photomicrograph.
  • the metal substrate has an irregular surface, and an interfacial boundary comprising an ammonium fluoride-containing base layer is formed at the surface of the substrate.
  • the silicon oxide-containing layer formed on the base layer shows excellent integrity, and both coating layers and therefore provide a superior corrosion and abrasion resistant surface.
  • Abrasion resistance can be measured according to Federal Test Method Std. No. 141C, Method 6192.1.
  • coatings produced according to the invention having a thickness of 12.7-25.4 ⁇ m (0.5 to 1.0 mil) will withstand at least 1,000 wear cycles before the appearance of the bare metal substrate using a 1.0 kg load on a CS-17 abrading wheel. More preferably, the coatings will withstand at least about 2,000 wear cycles before the appearance of the metal substrate, and most preferably, the coatings will withstand at least about 4,000 wear cycles using a 1.0 kg load on a CS-17 abrading wheel.
  • Corrosion resistance can be measured according to ASTM standards. Included in these tests is the salt fog test, ASTM B117, as evaluated by ASTM D1654, procedures A and B.
  • coatings produced according to the invention achieve a rating of at least about 9 after 24 hours in salt fog. More preferably, the coatings achieve a rating of at least about 9 after 100 hours, and most preferably, at least about 9 after 200 hours in salt fog.
  • the magnesium-containing articles may be used as is, offering a superb finish and excellent corrosion resistant properties, or they may be further coated using an optional finish coating such as a paint or a sealant.
  • an optional finish coating such as a paint or a sealant.
  • the structure and morphology of the silicon oxide-containing coating readily permit the use of a wide number of additional finish coatings which offer further corrosion resistance or decorative properties to the magnesium containing articles.
  • the silicon oxide-containing coating provides an excellent paint base having excellent corrosion resistance and offering excellent adhesion under both wet and dry conditions, for instance, the water immersion test, ASTM D3359, test method B.
  • the optional finish coatings may include organic and inorganic compositions as well as paints and other decorative and protective organic coatings.
  • any paint which adheres well to glassy and metallic surfaces may be used as the optional finish coating.
  • Representative, non-limiting inorganic compositions for use as an outer coating include additional alkali metal silicates, phosphates, borates, molydates and vanadates.
  • Representative, non-limiting organic outer coatings include polymers such as polyfluoroethylene, polyurethane and polyglycol. Additional finish coating materials will be known to those skilled in the art. Again, these optional finish coatings are not necessary to obtain excellent corrosion resistance, their use may achieve decorative or further improve the protective qualities of the coating.
  • coatings produced according to the invention having an optional finish coating, achieve a rating of at least about 8 after 700 hours in salt fog. More preferably, the coatings achieve a rating of at least about 9 after 700 hours, and most preferably, at least about 10 after 700 hours in salt fog.
  • Magnesium test panels (AZ91D) were cleaned immersing them in an aqueous solution of sodium pyrophosphate, sodium borate and sodium fluoride at about 70°C and a pH of about 10.5 for about 5 minutes. The panels were then placed in a 0.5 M ammonium fluoride bath at 70° for 30 minutes. The panels were then rinsed and placed in a silicate-containing bath. The silicate bath was prepared by first dissolving 50 g potassium hydroxide in 10 L water. 200 milliliters of a commercially available potassium silicate concentrate (20% w/w SiO2) was then added to the above solution. Finally 50 g of potassium fluoride was added to the above solution.
  • the bath then has a pH of about 12.5 and a concentration of potassium hydroxide about 5 g/L, about 16 g/L potassium silicate and about 5 g/L potassium fluoride.
  • the panels were then placed in the bath and connected to the positive lead of a rectifier.
  • a stainless steel panel served as the cathode and was connected to the negative lead of the rectifier capable of delivering a pulsed DC signal.
  • the voltage was increased over a 30 second period to 150 V and then the current adjusted to sustain a current density of 30 mA/cm2. After 30 minutes, the silicon oxide-containing coating was approximately 20 ⁇ m thick.
  • Examples II-VIII were prepared according to the process of Example I with the quantities of components as shown in Tables IV and V below.
  • Abrasion resistance testing (141C) of these test panels resulted in wear cycles of at least about 2,000 before the appearance of the metal substrate using a 1.0 kg load on CS-17 abrading wheels.
  • Test panels coated according to Examples I and IX were primed with an acid catalyst primer and then painted with a high temperature enamel. The panels were then immersed in water for four (4) days at 38°C (100°F) and subjected to ASTM D3359, method B. The panels achieved a rating of 5/5, the highest possible rating as no flaking of the coatings could be observed.

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Claims (30)

  1. Ein Verfahren zur Herstellung einer verbesserten, korrosionsbeständigen Beschichtung auf einem magnesiumhaltigen Gegenstand, wobei das Verfahren umfaßt:
    (a) Behandlung des Gegenstandes mit einer ersten wässrigen Lösung bei einem pH von 5 bis 8 und einer Temperatur von 40 bis 100°C, wobei die Lösung 0,2- bis 5-molar Ammoniumfluorid umfaßt, um eine metallammoniumfluoridhaltige Schicht an der Oberfläche des Gegenstandes zu erzeugen, um einen vorbehandelten Gegenstand zu bilden;
    (b) Hineingeben des vorbehandelten Gegenstandes in eine zweite wässrige elektrolytische Lösung mit einem pH von wenigstens 12,5, welche umfaßt:
    (i) 2 bis 12 g/l eines wässrigen löslichen Hydroxids;
    (ii) 2 bis 15 g/l einer wässrigen löslichen fluoridhaltigen Zusammensetzung, die ausgewählt ist aus der Gruppe, die aus Fluoriden, Fluorosilicaten und Mischungen derselben besteht; und
    (iii) 5 bis 30 g/l eines Alkalimetallsilicats;
    (c) Aufbau einer Spannungsdifferenz zwischen einer Anode, die den vorbehandelten Gegenstand umfaßt, und einer Kathode in der elektrolytischen Lösung von wenigstens 100 Volt, um eine Stromdichte von 2 bis 90 mA/cm² zu erzeugen;
    wobei eine siliciumoxidhaltige Beschichtung auf dem Gegenstand gebildet wird.
  2. Das Verfahren nach Anspruch 1, wobei der pH von Schritt (a) 6,3 bis 6,7 ist.
  3. Das Verfahren nach Anspruch 1, wobei die Temperatur der ersten Lösung 55 bis 85°C ist.
  4. Das Verfahren nach Anspruch 1, das 0,3- bis 2,0-molar Ammoniumfluorid umfaßt.
  5. Das Verfahren nach Anspruch 1, wobei der pH von Schritt (b) 12,5 bis 13 ist.
  6. Das Verfahren nach Anspruch 1, wobei das Hydroxid von Schritt (b) ein Alkalimetallhydroxid ist.
  7. Das Verfahren nach Anspruch 1, wobei die fluoridhaltige Zusammensetzung von Schritt (b) ausgewählt ist aus der Gruppe, die aus Natriumfluorid, Kaliumfluorid, Fluorwasserstoffsäure, Lithiumfluorid, Rubidiumfluorid, Cäsiumfluorid und einer Mischung derselben besteht.
  8. Das Verfahren nach Anspruch 1, wobei das Fluorosilicat von Schritt (b) ausgewählt ist aus der Gruppe, die aus Kaliumfluorosilicat, Natriumfluorosilicat, Lithiumfluorosilicat und einer Mischung derselben besteht.
  9. Das Verfahren nach Anspruch 1, wobei das Silicat von Schritt (b) ausgewählt ist aus der Gruppe, die aus Kaliumsilicat, Natriumsilicat, Lithiumsilicat und einer Mischung derselben besteht.
  10. Das Verfahren nach Anspruch 1, wobei die Temperatur der zweiten Lösung 5 bis 30°C ist.
  11. Das Verfahren nach Anspruch 1, wobei die Spannungsdifferenz von Schritt (c) 200 bis 400 Volt ist.
  12. Das Verfahren nach Anspruch 1, wobei die Stromdichte von Schritt (c) 5 bis 70 mA/cm² ist.
  13. Das Verfahren nach Anspruch 1, das außerdem das Verbinden der Anode und Kathode mit einer Stromquelle umfaßt.
  14. Das Verfahren nach Anspruch 13, wobei die Stromquelle eine Stromquelle für gleichgerichteten Wechselstrom ist.
  15. Das Verfahren nach Anspruch 14, wobei die Stromquelle für gleichgerichteten Wechselstrom eine gepulste Ganzwellengleichgerichtete Stromquelle ist.
  16. Das Verfahren nach Anspruch 1, das außerdem das Versiegeln der siliciumoxidhaltigen Beschichtung umfaßt.
  17. Das Verfahren nach Anspruch 16, wobei die siliciumoxidhaltige Beschichtung mit einer anorganischen Beschichtung versiegelt wird.
  18. Das Verfahren nach Anspruch 16, wobei die siliciumoxidhaltige Beschichtung mit einer organischen Beschichtung versiegelt wird.
  19. Das Verfahren nach Anspruch 1, wobei das Verfahren im wesentlichen frei von Chrom(VI) ist.
  20. Ein magnesiumhaltiges Substrat, das gemäß dem Verfahren nach Anspruch 1 beschichtet ist.
  21. Ein Verfahren zur Herstellung einer verbesserten, korrosionsbeständigen Beschichtung auf einem magnesiumhaltigen Gegenstand, wobei das Verfahren umfaßt:
    (a) Behandlung des Gegenstandes mit einer ersten wässrigen Lösung bei einem pH von 5 bis 8 und einer Temperatur von 40 bis 100°C, wobei die Lösung 0,2- bis 5-molar Ammoniumfluorid umfaßt, um eine metallammoniumfluoridhaltige Schicht an der Oberfläche des Gegenstandes zu erzeugen, um einen vorbehandelten Gegenstand zu bilden;
    (b) Hineingeben des vorbehandelten Gegenstandes in eine zweite wässrige elektrolytische Lösung mit einem pH von wenigstens 12,5, welche umfaßt:
    (i) 2 bis 12 g/l eines wässrigen löslichen Hydroxids; und
    (ii) 2 bis 30 g/l eines Alkalimetallfluorosilicats; und
    (c) Aufbau einer Spannungsdifferenz zwischen einer Anode, die den vorbehandelten Gegenstand umfaßt, und einer Kathode in der elektrolytischen Lösung von wenigstens 100 Volt, um eine Stromdichte von 2 bis 90 mA/cm² zu erzeugen;
    wobei eine siliciumoxidhaltige Beschichtung auf dem Gegenstand gebildet wird.
  22. Ein magnesiumhaltiger Gegenstand, der verbesserte Korrosions- und Abriebbeständigkeit bietet, wobei der Gegenstand ein magnesiumhaltiges Substrat, eine erste Grundschicht, die ein Metallammoniumfluorid umfaßt, und eine zweite äußere Schicht, die ein Siliciumoxid umfaßt, umfaßt.
  23. Der Gegenstand nach Anspruch 22, wobei das Metallammoniumfluorid Magnesiumammoniumfluorid umfaßt.
  24. Der Gegenstand nach Anspruch 22, wobei die Grundschicht zusätzlich ein Metallammoniumoxofluorid umfaßt.
  25. Der Gegenstand nach Anspruch 24, wobei das Metallammoniumoxofluorid Magnesiumammoniumoxofluorid umfaßt.
  26. Der Gegenstand nach Anspruch 22, der außerdem eine dritte, versiegelnde Schicht umfaßt, die auf dar zweiten äußeren Schicht angeordnet ist.
  27. Der Gegenstand nach Anspruch 22, der außerdem eine vierte Finish-Schicht umfaßt, die auf der zweiten äußeren Schicht angeordnet ist.
  28. Der Gegenstand nach Anspruch 27, der außerdem eine vierte Finish-Schicht umfaßt, die auf der dritten, versiegelnden Schicht angeordnet ist.
  29. Der Gegenstand nach Anspruch 22, der im wesentlichen frei von Chrom(VI) ist.
  30. Ein magnesiumhaltiger Gegenstand, der ein magnesiumhaltiges Substrat, eine erste Grundschicht, die Metallammoniumfluorid umfaßt, und eine zweite, äußere Schicht, die ein Siliciumoxid umfaßt, umfaßt, wobei der Gegenstand mit einer Beschichtungsdicke von 12,7 µm (0,5 mil) wenigstens 1.000 Abriebzyklen vor dem Erscheinen des Substrats bei Verwendung einer 1,0 kg-Belastung auf einem CS-17-Abriebrad gemäß Federal Test Method Std. No. 141C, Method 6192.1, aushalten wird.
EP92907909A 1991-02-26 1992-02-25 Zweistufiges chemisches bzw elektrochemisches verfahren zur beschichtung von magnesium Expired - Lifetime EP0573585B1 (de)

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US66150391A 1991-02-26 1991-02-26
US661503 1991-02-26
PCT/US1992/001495 WO1992014868A1 (en) 1991-02-26 1992-02-25 Two-step chemical/electrochemical process for coating magnesium
CN92105170A CN1049701C (zh) 1991-02-26 1992-06-26 在含镁工件上形成改进了耐蚀性的镀层的方法及含镁工件

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AU (1) AU1535392A (de)
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DE (1) DE69200922T2 (de)
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DE112009001005B4 (de) * 2008-04-25 2017-06-14 GM Global Technology Operations LLC (n. d. Ges. d. Staates Delaware) Verfahren zum Schützen eines Gegenstandes gegen Korrosion und Verfahren zum Schützen einer Magnesiumoberfläche

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US5266412A (en) 1991-07-15 1993-11-30 Technology Applications Group, Inc. Coated magnesium alloys
US7396446B2 (en) * 2001-08-14 2008-07-08 Keronite International Limited Magnesium anodisation methods
US6916414B2 (en) * 2001-10-02 2005-07-12 Henkel Kommanditgesellschaft Auf Aktien Light metal anodization
US7578921B2 (en) 2001-10-02 2009-08-25 Henkel Kgaa Process for anodically coating aluminum and/or titanium with ceramic oxides
US7569132B2 (en) 2001-10-02 2009-08-04 Henkel Kgaa Process for anodically coating an aluminum substrate with ceramic oxides prior to polytetrafluoroethylene or silicone coating
US7452454B2 (en) 2001-10-02 2008-11-18 Henkel Kgaa Anodized coating over aluminum and aluminum alloy coated substrates
US6495267B1 (en) * 2001-10-04 2002-12-17 Briggs & Stratton Corporation Anodized magnesium or magnesium alloy piston and method for manufacturing the same
JP2007009319A (ja) * 2005-06-01 2007-01-18 Meira Corp 保護被膜形成用組成物、金属成型体の製造方法および金属成型体
US9701177B2 (en) 2009-04-02 2017-07-11 Henkel Ag & Co. Kgaa Ceramic coated automotive heat exchanger components
JP5595874B2 (ja) * 2010-11-04 2014-09-24 三井金属鉱業株式会社 マグネシウム合金の表面処理方法
CN103088385A (zh) * 2012-12-01 2013-05-08 江门市华恒灯饰有限公司 微弧氧化电解液配方
WO2014203919A1 (ja) * 2013-06-19 2014-12-24 堀金属表面処理工業株式会社 マグネシウム合金製品の製造方法
KR20170029545A (ko) * 2014-07-17 2017-03-15 헨켈 아게 운트 코. 카게아아 마그네슘 합금을 위한 전자세라믹 코팅
JP6659961B2 (ja) * 2016-08-10 2020-03-04 富士通株式会社 マグネシウム合金基体、電子機器及び耐食性被膜の形成方法
CN106835227B (zh) * 2016-12-05 2018-11-13 浙江工业大学 一种基于卤素效应和陶瓷涂层提高钛基合金抗高温氧化性能的方法
CN106906505B (zh) * 2016-12-31 2019-01-08 浙江工业大学 一种基于卤素效应和预处理得到陶瓷涂层提高钛基合金抗高温氧化性能的方法
JP7418117B2 (ja) * 2018-12-17 2024-01-19 キヤノン株式会社 マグネシウム－リチウム系合金部材及びその製造方法
US11180832B2 (en) 2018-12-17 2021-11-23 Canon Kabushiki Kaisha Magnesium-lithium alloy member, manufacturing method thereof, optical apparatus, imaging apparatus, electronic apparatus and mobile object

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4184926A (en) * 1979-01-17 1980-01-22 Otto Kozak Anti-corrosive coating on magnesium and its alloys
US4620904A (en) * 1985-10-25 1986-11-04 Otto Kozak Method of coating articles of magnesium and an electrolytic bath therefor
US4744872A (en) * 1986-05-30 1988-05-17 Ube Industries, Ltd. Anodizing solution for anodic oxidation of magnesium or its alloys
JPS63277793A (ja) * 1987-05-08 1988-11-15 Ube Ind Ltd マグネシウムまたはその合金の陽極酸化処理液

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE112009001005B4 (de) * 2008-04-25 2017-06-14 GM Global Technology Operations LLC (n. d. Ges. d. Staates Delaware) Verfahren zum Schützen eines Gegenstandes gegen Korrosion und Verfahren zum Schützen einer Magnesiumoberfläche

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EP0573585A1 (de) 1993-12-15
CN1049701C (zh) 2000-02-23
AU1535392A (en) 1992-09-15
BR9205679A (pt) 1994-06-21
GR3015377T3 (en) 1995-06-30
JPH06504815A (ja) 1994-06-02
DE69200922D1 (de) 1995-01-26
CA2100168C (en) 2004-09-14
CN1080671A (zh) 1994-01-12
JP3183512B2 (ja) 2001-07-09
DE69200922T2 (de) 1995-05-04
NO933024D0 (no) 1993-08-25
ATE115653T1 (de) 1994-12-15
CA2100168A1 (en) 1992-08-27
NO308907B1 (no) 2000-11-13
ES2068710T3 (es) 1995-04-16
DK0573585T3 (da) 1995-03-06
NO933024L (no) 1993-10-14
WO1992014868A1 (en) 1992-09-03

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