US3761364A - Self coloring anodic oxidation process for aluminum and its alloys - Google Patents

Self coloring anodic oxidation process for aluminum and its alloys Download PDF

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Publication number
US3761364A
US3761364A US00234682A US3761364DA US3761364A US 3761364 A US3761364 A US 3761364A US 00234682 A US00234682 A US 00234682A US 3761364D A US3761364D A US 3761364DA US 3761364 A US3761364 A US 3761364A
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US
United States
Prior art keywords
aluminum
cathodes
alloys
electrolytic
self
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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 - Lifetime
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US00234682A
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English (en)
Inventor
C Micheletti
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.)
L ESERCIZIO DELL ISTITUTO SPER
SOC L ESERCIZIO DELL ISTITUTO SPERIMENTALE METALLI LEGGERI IT
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L ESERCIZIO DELL ISTITUTO SPER
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Publication of US3761364A publication Critical patent/US3761364A/en
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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
    • C25D11/14Producing integrally coloured layers

Definitions

  • the present invention relates to an improvement in the self-coloring anodic oxidation process for aluminum and its alloys, an improvement that allows one to reduce the consumption of the components constituting the electrolytic system and to reduce the formation of precipitates from that system.
  • An object of this invention is that of providing an improvement in the self-coloring anodic oxidizing process for aluminum and its alloys by which the previouslymentioned drawbacks will be eliminated or at least very considerably reduced.
  • an object of the present invention is that of providing a process that will reduce to a minimum the formation of precipitates from the electrolytic solution and consequently will reduce the harmful cloggings of the installation and reduction of the exchange capacities of the refrigerating apparatus and of the ion exchanging resin columns.
  • a further object of this invention is that of providing a process which will reduce the consumption of the components of the electrolytic system which is used, with considerable practical and economical advantages, thereby obtaining also an improved constancy of composition of the electrolytic system and therefore an improved reproducibility of the colorings obtained in the anodic coating, without requiring frequent and costly additions of electrolyte.
  • the carboxylic acid component may be selected from maleic, oxalic or tartaric acid either alone or in a binary or ternary combination thereof, and generally also in the presence of sulphuric acid.
  • the cooling of the cathodes is generally carried out by circulating inside the cathodes a conventional refrigerating fluid, for instance by using h'ollow cathodes or cathodes provided with coils incorporated therein.
  • the refrigerating fluid must have an inflow temperature to the cathodes below 25 C.; such a temperature must however be higher than the temperature that would bring about freezing of the electrolytic solution used in the cell.
  • EXAMPLE 1 The anodic oxidation was carried out in successive batches of 50 minutes each and at a temperature of 22 C. at 1.5 a./dm. through a self-coloring electrolyte of the MS-type consisting of an aqueous solution of maleic
  • a tank of about 150 liters capacity fitted with an ion-exchange column and an external heat exchanger.
  • AISI 316 stainless steel pipes
  • Running water was circulated within the pipes as refrigerating fluid, the running water having an inflow temperature of 125- 13 C.

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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)
  • Electrolytic Production Of Metals (AREA)
  • Primary Cells (AREA)
US00234682A 1971-03-15 1972-03-14 Self coloring anodic oxidation process for aluminum and its alloys Expired - Lifetime US3761364A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
IT2175371 1971-03-15

Publications (1)

Publication Number Publication Date
US3761364A true US3761364A (en) 1973-09-25

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ID=11186371

Family Applications (1)

Application Number Title Priority Date Filing Date
US00234682A Expired - Lifetime US3761364A (en) 1971-03-15 1972-03-14 Self coloring anodic oxidation process for aluminum and its alloys

Country Status (7)

Country Link
US (1) US3761364A (en:Method)
BE (1) BE780636A (en:Method)
CH (1) CH567109A5 (en:Method)
DE (1) DE2211845A1 (en:Method)
FR (1) FR2130193B1 (en:Method)
GB (1) GB1339878A (en:Method)
NL (1) NL7203204A (en:Method)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4056449A (en) * 1974-10-31 1977-11-01 Diamond Shamrock Technologies S.A. Electrowinning method
WO2020215041A1 (en) * 2019-04-18 2020-10-22 Lopez Steven Fluorescent anodization dye and associated methods

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4056449A (en) * 1974-10-31 1977-11-01 Diamond Shamrock Technologies S.A. Electrowinning method
WO2020215041A1 (en) * 2019-04-18 2020-10-22 Lopez Steven Fluorescent anodization dye and associated methods

Also Published As

Publication number Publication date
CH567109A5 (en:Method) 1975-09-30
BE780636A (fr) 1972-09-14
GB1339878A (en) 1973-12-05
NL7203204A (en:Method) 1972-09-19
FR2130193B1 (en:Method) 1977-04-01
FR2130193A1 (en:Method) 1972-11-03
DE2211845A1 (de) 1972-09-28

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