DE906878C - Electrolytic oxidation of aluminum and aluminum alloys, especially in the pull-through process - Google Patents

Electrolytic oxidation of aluminum and aluminum alloys, especially in the pull-through process

Info

Publication number
DE906878C
DE906878C DES14665D DES0014665D DE906878C DE 906878 C DE906878 C DE 906878C DE S14665 D DES14665 D DE S14665D DE S0014665 D DES0014665 D DE S0014665D DE 906878 C DE906878 C DE 906878C
Authority
DE
Germany
Prior art keywords
aluminum
pull
electrolytic oxidation
aluminum alloys
alloys
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.)
Expired
Application number
DES14665D
Other languages
German (de)
Inventor
Ernst Berganski
Dr Nikolai Budiloff
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.)
Siemens AG
Original Assignee
Siemens 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 Siemens AG filed Critical Siemens AG
Priority to DES14665D priority Critical patent/DE906878C/en
Application granted granted Critical
Publication of DE906878C publication Critical patent/DE906878C/en
Expired legal-status Critical Current

Links

Classifications

    • 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

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Chemical Treatment Of Metals (AREA)

Description

Elektrolytische Oxydation von Aluminium und Aluminiumlegierungen, insbesondere im Durchzugsverfahren hie elektrolytische Oxydation von Aluminium oder Aluminiumlegierungen in schwefelsaurer oder oxalsaurer Lösung wird gewöhnlich bei verhältnismäßig niedrigen Temperaturen und Stromdichten von i bis a AM M2 durchgeführt, da bei Temperaturen über .4o° und normaler Behandlungsdauer die Schichten pulvrig und unbrauchbar werden. Auch die Anwendung höherer Stromdichten bei normalen Temperaturen führt nicht zu brauchbaren Ergebnissen. Man erhält meist Anfressungen des Materials.Electrolytic oxidation of aluminum and aluminum alloys, especially in the pull-through process called electrolytic oxidation of aluminum or aluminum alloys in sulfuric acid or oxalic acid solution is usually carried out at relatively low temperatures and current densities of 1 to a AM M2 , since the layers are at temperatures above .40 ° and normal treatment duration become powdery and unusable. Even the use of higher current densities at normal temperatures does not lead to useful results. You usually get pitting of the material.

Man hat auch versucht, bei Temperaturen von 8o bis 9o2 und Schwefelsäuregehalten von cgo bis i oo o/o zu arbeiten. So hohe Konzentrationen sind aber zu der Erzeugung einer entsprechend starken Schutzschicht nicht geeignet. Das Rücklösungsv ermögen solcher konzentrierten Säure ist so hoch, daß im besten Falle nur ganz dünne Schichten erhalten werden, die bei geringen mechanischen Einwirkungen sofort beschädigt werden.Attempts have also been made at temperatures of 8o to 9o2 and sulfuric acid levels to work from cgo to i oo o / o. However, such high concentrations are involved in the production a suitably thick protective layer is not suitable. Enable the redemption such concentrated acid is so high that in the best case only very thin layers are obtained, which are damaged immediately in the event of minor mechanical effects.

1?s hat sich nun überraschenderweise gezeigt, daß auch mit höheren Stromdichten und bei gleichzeitiger Anwendung höherer Radtemperaturen gearbeitet werden kann, wenn erfindungsgemäß die elektrolytische Oxydation von Aluminium und Aluminiumlegierungen, vorzugsweise von Aluminiumdrähten und Aluminiumbändern im Durchzugsverfahren, in schwefelsauren oder oxalsauren Bädern der üblichen Konzentrationen durchgeführt wird, wobei die elektrolytische Behandlung bei Temperaturen von über 50°1 mit Stromdichten von etwa ioo A/,dm2 oder mehr erfolgt und die Behandlungsdauer höchstens i Minute beträgt. Auf diese Weise werden völlig einwandfreie, gut biegsaure Oxydschichten erhalten. Die Durchzugsgeschwindigkeit beträgt z. B. bei einem Bad von 30 cm Länge für Aluminiumdraht ioo bis 500 m je Stunde, die Stromdichte z2o A/dm2 und die Temperatur des Elektrolyts 6o bis 70°,. Die üblichen Konzentrationen betragen bei Schwefelsäure etwa io bis 30°/o, bei Oxalsäure 2,i/2 bis :2o"/o. Die Schichten weisen eine Dicke von mehreren ,u auf und sind nicht nur sehr gut biegsam; sondern auch gut anfärbbar. Das erfindungsgemäße Verfahren gibt die Möglichkeit, den Durchsatz der Bäder je Zeiteinheit auf mindestens den iofachen Betrag zu erhöhen.1? S has now surprisingly shown that it is also possible to work with higher current densities and at the same time using higher wheel temperatures if, according to the invention, the electrolytic oxidation of aluminum and aluminum alloys, preferably of aluminum wires and aluminum strips, in the pull-through process, in sulfuric acid or oxalic acid baths of the usual concentrations is carried out, the electrolytic treatment being carried out at temperatures of over 50 ° 1 with current densities of about 100 A /, dm2 or more and the treatment duration being at most 1 minute. In this way, completely flawless, highly flexible oxide layers are obtained. The pull-through speed is z. B. in a bath of 30 cm length for aluminum wire 100 to 500 m per hour, the current density z2o A / dm2 and the temperature of the electrolyte 6o to 70 °. The usual concentrations for sulfuric acid are about 10 to 30 per cent, for oxalic acid 2, 1/2 to: 20 "/ 0. The layers are several microns thick and are not only very flexible, but also easy to dye The method according to the invention makes it possible to increase the throughput of the baths per unit of time to at least 10 times the amount.

Claims (1)

PATENTANSPRUCH: Verfahren zur elektrolytischen Oxydation von Aluminium und Aluminiumlegierungen, vorzugsweise von Aluminiumdrähten und Aluminiumbändern im Durchzugsverfahren, in schwefelsauren oder oxalsauren Bädern der üblichen Konzentrationen, dadurch gekennzeichnet, daß die elektrolytische Behandlung bei Temperaturen von über 5o°' mit Stromdichten von etwa ioo A/dm2 oder mehr erfolgt, wobei die Behandlungsdauer höchstens z Minute beträgt.PATENT CLAIM: Process for the electrolytic oxidation of aluminum and aluminum alloys, preferably of aluminum wires and aluminum strips in the pull-through process, in sulfuric acid or oxalic acid baths of the usual concentrations, characterized in that the electrolytic treatment at temperatures of takes place over 50 ° 'with current densities of about 100 A / dm2 or more, the duration of the treatment is at most z minute.
DES14665D 1939-12-21 1939-12-21 Electrolytic oxidation of aluminum and aluminum alloys, especially in the pull-through process Expired DE906878C (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
DES14665D DE906878C (en) 1939-12-21 1939-12-21 Electrolytic oxidation of aluminum and aluminum alloys, especially in the pull-through process

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DES14665D DE906878C (en) 1939-12-21 1939-12-21 Electrolytic oxidation of aluminum and aluminum alloys, especially in the pull-through process

Publications (1)

Publication Number Publication Date
DE906878C true DE906878C (en) 1954-03-18

Family

ID=7474625

Family Applications (1)

Application Number Title Priority Date Filing Date
DES14665D Expired DE906878C (en) 1939-12-21 1939-12-21 Electrolytic oxidation of aluminum and aluminum alloys, especially in the pull-through process

Country Status (1)

Country Link
DE (1) DE906878C (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2963409A (en) * 1957-10-07 1960-12-06 Reynolds Metals Co Flexible anodic coating
DE1184174B (en) * 1957-08-12 1964-12-23 Bolam Nominees Ltd Method and device for anodic treatment of a surface side of a metal strip

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1184174B (en) * 1957-08-12 1964-12-23 Bolam Nominees Ltd Method and device for anodic treatment of a surface side of a metal strip
US2963409A (en) * 1957-10-07 1960-12-06 Reynolds Metals Co Flexible anodic coating

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