EP0607579A1 - Procédé d'anodisation - Google Patents

Procédé d'anodisation Download PDF

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Publication number
EP0607579A1
EP0607579A1 EP93120288A EP93120288A EP0607579A1 EP 0607579 A1 EP0607579 A1 EP 0607579A1 EP 93120288 A EP93120288 A EP 93120288A EP 93120288 A EP93120288 A EP 93120288A EP 0607579 A1 EP0607579 A1 EP 0607579A1
Authority
EP
European Patent Office
Prior art keywords
approximately
electrolyte
minutes
h2so4
voltage
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.)
Withdrawn
Application number
EP93120288A
Other languages
German (de)
English (en)
Inventor
Erich Kock
Volker Muss
Christoph Dr. Matz
Fekko De Wit
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Airbus Defence and Space GmbH
Original Assignee
Deutsche Aerospace AG
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 Deutsche Aerospace AG filed Critical Deutsche Aerospace AG
Publication of EP0607579A1 publication Critical patent/EP0607579A1/fr
Withdrawn legal-status Critical Current

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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
    • C25D11/04—Anodisation of aluminium or alloys based thereon
    • C25D11/06—Anodisation of aluminium or alloys based thereon characterised by the electrolytes used
    • C25D11/08—Anodisation of aluminium or alloys based thereon characterised by the electrolytes used containing inorganic acids

Definitions

  • the invention relates to a method for the anodic oxidation of structural elements made of aluminum or magnesium materials in a phosphorus-containing aqueous electrolyte.
  • Such a method has become known from DE 27 05 652 C2 and is preferably used in aerospace engineering for pretreating structural elements made of aluminum or high-strength aluminum alloys which are to be bonded to one another or which are combined with an organic, metallic or inorganic Coating should be provided.
  • the oxide skin created on the workpiece surface serves the purpose To improve the adhesion properties of this surface in the long term, the aim being to produce the softest possible, thin, but above all porous oxide layer, through which the effective surface is enlarged and the greatest possible number of active centers for the formation of adhesive bonds is created.
  • anodizing processes are also used in practice for pretreating workpieces made of aluminum or aluminum alloys, in which electrolytes based on chromic acid or sulfuric acid are used.
  • the oxide layers produced in these processes can be compressed and are then also suitable as sole corrosion protection.
  • Chromic acid anodizing has the advantage that almost optimal surfaces can be achieved with it in terms of morphology and the layer thickness of the oxide layer, but at the same time this method is relatively complex and time-consuming to carry out and is problematic in terms of occupational hygiene and environmental issues, since working with Chromium salts and chromic acid are associated with an increased health risk. Furthermore, this process must be carried out at an elevated temperature.
  • the oxide layers produced during phosphoric acid anodizing are generally mechanically unstable and to one Supplemented by organic coating materials. This means that the workpieces made of aluminum or aluminum alloys pretreated with these methods can only be processed and inspected without contact until the primer used for the subsequent bonding has hardened.
  • the object of the invention is to develop a method of the type mentioned in such a way that it can achieve an optimal surface finish similar to chromic acid anodizing, but at the same time offers much easier handling, shortened process duration and costs, and significantly improved environmental protection.
  • the invention solves this problem by a method having the characterizing features of claim 1.
  • the use of a mixed electrolyte of phosphoric and sulfuric acid which is provided according to the invention, creates a method with which oxide layers can be produced on workpieces made of aluminum and its alloys, which Oxide layers that can be achieved by chromic acid anodizing are not only comparable in terms of morphology and layer thickness, but also have good long-term stability.
  • the oxide layers which can be produced using the method according to the invention are notable for high adhesive strength and ductility and have good corrosion resistance.
  • Another advantage of the method according to the invention is that, by varying the process parameters, the same electrolyte can be used for the production of a compressed anodized layer, as corrosion protection and for the pretreatment in a subsequent coating or gluing. It can ideally do this in each case machining material to be adjusted.
  • the invention will be explained in more detail below on the basis of an exemplary embodiment, the figure representing the chronological course of the anodizing process in a voltage-time diagram.
  • the workpiece made of a high-strength aluminum alloy which is to be prepared for subsequent gluing or coating, for example with an organic substance, is first subjected to a cleaning and activation step using a commercially available cleaning agent and an oxidizing acid bath, for example made of nitric acid (HNO3), after each each of these steps is rinsed with water.
  • a cleaning and activation step using a commercially available cleaning agent and an oxidizing acid bath, for example made of nitric acid (HNO3), after each each of these steps is rinsed with water.
  • HNO3 nitric acid
  • the workpiece is then placed in an aqueous electrolyte which has a concentration of about 100 g / l sulfuric acid (H2SO4) and phosphoric acid (H3PO4), so that these two components are in a mixing ratio of about 1: 1.
  • the bath temperature is about 27 o C.
  • the workpiece to be oxidized is connected to the positive pole of a direct current source, while an electrode made of pure aluminum, lead or a high-alloy steel is used as the cathode.
  • the applied voltage is increased over a period of about three minutes (t 1) from zero to a value between 15 and 20 volts. This voltage value is then kept constant for about 15 minutes before the voltage is switched off. The workpiece is then removed from the bath and the residue of the The electrolyte is rinsed off in about two minutes.
  • the oxide layer produced in this way has a thickness of about 3 to 3.5 micrometers, is of high ductility and has a high pore volume and thus a large number of active centers for the formation of adhesive bonds.
  • a salt spray test with aging in accordance with DIN 50021 confirms the good long-term durability of this layer.

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  • Chemical & Material Sciences (AREA)
  • Inorganic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Chemical Treatment Of Metals (AREA)
  • ing And Chemical Polishing (AREA)
EP93120288A 1992-12-19 1993-12-16 Procédé d'anodisation Withdrawn EP0607579A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE4243164 1992-12-19
DE19924243164 DE4243164A1 (de) 1992-12-19 1992-12-19 Verfahren zur anodischen Oxidation

Publications (1)

Publication Number Publication Date
EP0607579A1 true EP0607579A1 (fr) 1994-07-27

Family

ID=6475893

Family Applications (1)

Application Number Title Priority Date Filing Date
EP93120288A Withdrawn EP0607579A1 (fr) 1992-12-19 1993-12-16 Procédé d'anodisation

Country Status (3)

Country Link
EP (1) EP0607579A1 (fr)
JP (1) JPH06299393A (fr)
DE (1) DE4243164A1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8889226B2 (en) 2011-05-23 2014-11-18 GM Global Technology Operations LLC Method of bonding a metal to a substrate
WO2017183965A1 (fr) 2016-04-18 2017-10-26 Fokker Aerostructures B.V. Procédé d'anodisation d'un article en aluminium ou en alliage de celui-ci

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8309237B2 (en) 2007-08-28 2012-11-13 Alcoa Inc. Corrosion resistant aluminum alloy substrates and methods of producing the same
AU2017314185B2 (en) * 2016-08-17 2022-07-14 Cirrus Materials Science Limited Method to create thin functional coatings on light alloys

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3098804A (en) * 1960-03-28 1963-07-23 Kaiser Aluminium Chem Corp Metal treatment
FR2341443A1 (fr) * 1976-02-23 1977-09-16 Polychrome Corp Procede de production de plaques d'impression lithographiques et produits ainsi obtenus
JPS5350082A (en) * 1976-10-19 1978-05-08 Nippon Keikinzoku Sougou Kenki Manufacture of catalyst carriers
JPS54120249A (en) * 1978-03-13 1979-09-18 Kobe Steel Ltd Forming method for anodic oxide film on aluminum alloy

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2703781A (en) * 1950-05-25 1955-03-08 Kaiser Aluminium Chem Corp Anodic treatment of aluminum surfaces
US3349014A (en) * 1964-08-28 1967-10-24 Mc Donnell Douglas Corp Method and composition for the treatment of an aluminum surface
DE2836803A1 (de) * 1978-08-23 1980-03-06 Hoechst Ag Verfahren zur anodischen oxidation von aluminium und dessen verwendung als druckplatten-traegermaterial
GB8427943D0 (en) * 1984-11-05 1984-12-12 Alcan Int Ltd Anodic aluminium oxide film
DE3808609A1 (de) * 1988-03-15 1989-09-28 Electro Chem Eng Gmbh Verfahren zur erzeugung von korrosions- und verschleissbestaendigen schutzschichten auf magnesium und magnesiumlegierungen

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3098804A (en) * 1960-03-28 1963-07-23 Kaiser Aluminium Chem Corp Metal treatment
FR2341443A1 (fr) * 1976-02-23 1977-09-16 Polychrome Corp Procede de production de plaques d'impression lithographiques et produits ainsi obtenus
JPS5350082A (en) * 1976-10-19 1978-05-08 Nippon Keikinzoku Sougou Kenki Manufacture of catalyst carriers
JPS54120249A (en) * 1978-03-13 1979-09-18 Kobe Steel Ltd Forming method for anodic oxide film on aluminum alloy

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
DATABASE WPI Week 7824, Derwent World Patents Index; AN 78-43046A *
PATENT ABSTRACTS OF JAPAN vol. 3, no. 142 (C - 65) 24 November 1979 (1979-11-24) *

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8889226B2 (en) 2011-05-23 2014-11-18 GM Global Technology Operations LLC Method of bonding a metal to a substrate
WO2017183965A1 (fr) 2016-04-18 2017-10-26 Fokker Aerostructures B.V. Procédé d'anodisation d'un article en aluminium ou en alliage de celui-ci
CN109415836A (zh) * 2016-04-18 2019-03-01 福克航空结构公司 铝或其合金制品的阳极氧化方法
US11326269B2 (en) 2016-04-18 2022-05-10 Fokker Aerostructures B.V. Anodizing an article of aluminum or alloy thereof

Also Published As

Publication number Publication date
DE4243164A1 (de) 1994-06-23
JPH06299393A (ja) 1994-10-25

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