CH417274A - Process for producing a boehmite layer on aluminum objects - Google Patents

Process for producing a boehmite layer on aluminum objects

Info

Publication number
CH417274A
CH417274A CH1218562A CH1218562A CH417274A CH 417274 A CH417274 A CH 417274A CH 1218562 A CH1218562 A CH 1218562A CH 1218562 A CH1218562 A CH 1218562A CH 417274 A CH417274 A CH 417274A
Authority
CH
Switzerland
Prior art keywords
producing
boehmite layer
aluminum
objects
aluminum objects
Prior art date
Application number
CH1218562A
Other languages
German (de)
Original Assignee
Alusuisse
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
Priority claimed from CH386662A external-priority patent/CH400718A/en
Application filed by Alusuisse filed Critical Alusuisse
Priority to CH1218562A priority Critical patent/CH417274A/en
Priority to GB1259763A priority patent/GB985300A/en
Publication of CH417274A publication Critical patent/CH417274A/en

Links

Classifications

    • CCHEMISTRY; METALLURGY
    • C23COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23FNON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
    • C23F3/00Brightening metals by chemical means
    • C23F3/02Light metals
    • C23F3/03Light metals with acidic solutions
    • CCHEMISTRY; METALLURGY
    • C23COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23CCOATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C22/00Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
    • C23C22/05Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions
    • C23C22/60Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using alkaline aqueous solutions with pH greater than 8
    • C23C22/66Treatment of aluminium or alloys based thereon
    • CCHEMISTRY; METALLURGY
    • C25ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25FPROCESSES FOR THE ELECTROLYTIC REMOVAL OF MATERIALS FROM OBJECTS; APPARATUS THEREFOR
    • C25F3/00Electrolytic etching or polishing
    • C25F3/16Polishing
    • C25F3/18Polishing of light metals
    • C25F3/20Polishing of light metals of aluminium

Landscapes

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

Description

  

  Zusatzpatent zum Hauptpatent Nr. 400 718    Verfahren zur Erzeugung einer     Böhmitschicht    auf     Aluminiumgegenständen       Das Hauptpatent Nr. 400 718 bezieht sich auf     ein     Verfahren zur Erzeugung einer     Böhmitschicht    auf  Aluminiumgegenständen durch Behandlung mit einer  heissen, wässerigen     Triäthanolaminlösung,    dadurch  gekennzeichnet, dass eine Lösung verwendet wird,  die höchstens 0,3 %     Triäthanolamin    enthält.  



  Die vorliegende Erfindung bezieht sich auf das  Verfahren zur Erzeugung einer     Böhmitschicht    auf  Aluminiumgegenständen nach dem     Patentanspruch     des Hauptpatentes, dadurch gekennzeichnet, dass die  Gegenstände vor dem Erzeugen der     Böhmitschicht     rein     chemisch    oder elektrochemisch geglänzt werden.  



  Es ist bekannt, dass Gegenstände aus Aluminium,  z. B. Küchen- und     Campinggeräte,    Drähte,     Draht-          geflechte,    Nieten, Schrauben beim Lagern vor dem  Verkauf oder beim Gebrauch infolge leichter Korro  sion     unansehnlich    werden, insbesondere wenn sie che  misch oder elektrochemisch geglänzt und nicht nach  träglich     anodisch        oxydiert    worden sind.

   Ausserdem sind  Gegenstände aus     aushärtbaren        Aluminiumlegierungen     nach dem     Lösungsglühen    und Abschrecken oft mit  einer unansehnlichen, grauen     Oxidschicht    bedeckt,  die durch     chemisches    oder     elektrochemisches    Glänzen  weggelöst wird. Die so erhaltenen glänzenden Ober  flächen sollen mindestens beim Lagern ihren Glanz  beibehalten, ohne dass eine teure     anodische    Oxydation  angewendet werden muss.  



  Es hat sich nun gezeigt, dass eine nach dem       Patentanspruch    des Hauptpatentes erzeugte     Böhmit-          schicht    geeignet ist, diese Aufgabe zu     erfüllen.     



  Die     Behandlung    in der heissen     Triäthanolamin-          Lösung    dauert wenige Minuten, z. B. 3 bis 10 min.  Massenartikel werden bei der Ausführung des er-         findungsgemässen    Verfahrens vorzugsweise rein che  misch geglänzt.  



  Es sind     zahlreiche        Verfahren    zum chemischen  Glänzen von Aluminium und     Aluminiumlegierungen     bekannt. Nach einem dieser Verfahren werden die  Teile während 3 bis 5 min in     einer    90 bis<B>95'</B> C  warmen, wässerigen Lösung von 95     Vol.%        Ortho-          phosphorsäure    (d = 1,75), 5     VolA    konzentrierter  Salpetersäure (d = 1,4) und 0,2     GewA        NiS04    - 7H20  behandelt.  



  Unter den elektrochemischen     Glänzverfahren    für  Aluminium und     Aluminiumlegierungen    sei z. B. fol  gendes erwähnt: Es wird mit einem 70 bis, 80  C       warmen        Elektrolyten    gearbeitet, der aus 70     Volum-          teilen    konzentrierter Schwefelsäure (d = 1,84),  15     Vol.%    60 %     iger        Orthophosphorsäure    (d = 1,7)  und 15     VolA    Wasser mit einem Zusatz von 0,5 bis  1     VolA    50 %     iger    Salpetersäure (35  Baume)

       besteht.     Es wird eine Spannung von 12 bis 18 V angelegt,  wodurch sich eine     anodische        Stromdichte    von 10 bis  15     A/dm2    ergibt. Die Dauer der Behandlung beträgt  1-8     min.     



  Die Behandlung in der heissen     Triäthanolamin-          Lösung    wird sofort im     Anschluss    an das Glänzen  und Spülen in Wasser vorgenommen.



  Additional patent to main patent No. 400 718 Process for producing a boehmite layer on aluminum objects The main patent No. 400 718 relates to a process for producing a boehmite layer on aluminum objects by treatment with a hot, aqueous triethanolamine solution, characterized in that a solution is used which Contains a maximum of 0.3% triethanolamine.



  The present invention relates to the method for producing a boehmite layer on aluminum objects according to the patent claim of the main patent, characterized in that the objects are polished chemically or electrochemically prior to producing the boehmite layer.



  It is known that articles made of aluminum, e.g. B. kitchen and camping equipment, wires, wire mesh, rivets, screws become unsightly when stored before sale or during use due to slight corrosion, especially if they are chemically or electrochemically polished and have not been subsequently anodically oxidized.

   In addition, objects made of hardenable aluminum alloys are often covered with an unsightly gray oxide layer after solution heat treatment and quenching, which is dissolved away by chemical or electrochemical glossing. The glossy surfaces obtained in this way should at least retain their gloss during storage without the need for expensive anodic oxidation.



  It has now been shown that a boehmite layer produced according to the patent claim of the main patent is suitable for fulfilling this task.



  The treatment in the hot triethanolamine solution takes a few minutes, for. B. 3 to 10 min. When the method according to the invention is carried out, mass-produced articles are preferably given a purely chemical shine.



  Numerous methods of chemically brightening aluminum and aluminum alloys are known. According to one of these processes, the parts are for 3 to 5 minutes in a 90 to 95 ° C warm, aqueous solution of 95% by volume of orthophosphoric acid (d = 1.75), 5% by volume of concentrated nitric acid (d = 1.4) and 0.2 GewA NiS04 - 7H20 treated.



  Among the electrochemical polishing processes for aluminum and aluminum alloys, e.g. B. The following is mentioned: An electrolyte with a temperature of 70 to .80 C is used, which is composed of 70 parts by volume of concentrated sulfuric acid (d = 1.84), 15% by volume of 60% orthophosphoric acid (d = 1.7) and 15 VolA water with an addition of 0.5 to 1 VolA 50% nitric acid (35 Baume)

       consists. A voltage of 12 to 18 V is applied, resulting in an anodic current density of 10 to 15 A / dm2. The duration of the treatment is 1-8 min.



  The treatment in the hot triethanolamine solution is carried out immediately after the polishing and rinsing in water.

 

Claims (1)

PATENTANSPRUCH Verfahren zur Erzeugung einer Böhmitschicht auf Aluminiumgegenständen nach dem Patentan- spruch des Hauptpatentes, dadurch gekennzeichnet, dass die Gegenstände vor dem Erzeugen der Bähmit schickt rein chemisch oder elektrochemisch geglänzt werden. PATENT CLAIM Process for producing a boehmite layer on aluminum objects according to the patent claim of the main patent, characterized in that the objects are chemically or electrochemically polished prior to producing the boehmite.
CH1218562A 1962-03-30 1962-10-17 Process for producing a boehmite layer on aluminum objects CH417274A (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
CH1218562A CH417274A (en) 1962-03-30 1962-10-17 Process for producing a boehmite layer on aluminum objects
GB1259763A GB985300A (en) 1962-03-30 1963-03-29 Process for coating aluminium articles

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CH386662A CH400718A (en) 1962-03-30 1962-03-30 Process for producing a boehmite layer on aluminum objects
CH1218562A CH417274A (en) 1962-03-30 1962-10-17 Process for producing a boehmite layer on aluminum objects

Publications (1)

Publication Number Publication Date
CH417274A true CH417274A (en) 1966-07-15

Family

ID=25694040

Family Applications (1)

Application Number Title Priority Date Filing Date
CH1218562A CH417274A (en) 1962-03-30 1962-10-17 Process for producing a boehmite layer on aluminum objects

Country Status (1)

Country Link
CH (1) CH417274A (en)

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