US3704209A - Method for electrochemical coloring of aluminum and alloys - Google Patents

Method for electrochemical coloring of aluminum and alloys Download PDF

Info

Publication number
US3704209A
US3704209A US54878A US3704209DA US3704209A US 3704209 A US3704209 A US 3704209A US 54878 A US54878 A US 54878A US 3704209D A US3704209D A US 3704209DA US 3704209 A US3704209 A US 3704209A
Authority
US
United States
Prior art keywords
aluminum
bath
alternating current
direct current
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 - Lifetime
Application number
US54878A
Other languages
English (en)
Inventor
Jos Patrie
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.)
Cegedur GP
Original Assignee
Cegedur GP
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 Cegedur GP filed Critical Cegedur GP
Application granted granted Critical
Publication of US3704209A publication Critical patent/US3704209A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

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
    • C25D11/18—After-treatment, e.g. pore-sealing
    • C25D11/20—Electrolytic after-treatment
    • C25D11/22—Electrolytic after-treatment for colouring layers

Definitions

  • This invention relates to the coloring of surfaces of aluminum or alloys of aluminum by electrochemical means.
  • oxide layers produced by anodizing aluminum can be given a stable finish color by depositing metal pigments into the pores of the layers by alternating current electrolysis in an aqueous acid solution of metal salts.
  • One of the electrodes is formed of the component to be colored, While the other electrode is an auxiliary electrode, which may be inert, i.e. for example of graphite, stainless steel or the dissolved metal that may consist of the same metal as the cation of the salt which is dissolved in the bath.
  • Deep color finishes can be obtained by prolonged electrolysis.
  • the slowness of the operation is a disadvantage from an economical point of view.
  • the present invention is distinguished by the fact that a direct current is superimposed upon the alternating current, with the intensity of the direct current being lower than the effective intensity of the alternating current.
  • the color finish is either strengthened or weakened by comparison to that which would be obtained during the same period of time with alternating current alone.
  • the process of this invention markedly reduces the dissolution of the electrode used as the auxiliary electrode, as distinguished from the rapid dissolution when alternating current is used alone, the latter of which has the disadvantage of enriching the bath with metal ions as well as changing the pH value.
  • Any electrical device enabling the electrolysis bath to be fed with superimposed alternating current can be used.
  • the arrangement shown in the figure which is given by way of illustration, but not by way of limitation, enables the alternating and direct components of the electrolysis installation to be precisely regulated.
  • the alternating current is provided by a variable ratio transformer 1 in which the primary winding is connected to the main line while the secondary winding comprisesa center tap. Each of the ends of the secondary winding is connected to a component or to a number of compo-.
  • the inert or soluble counter electrode is connected to the center tap of the secondary winding through a diode bridge.
  • the diode is fed by a variable ratio transformer 2.
  • the two alternations of current produced in the secondary winding are rectified. It is not absolutely essential to provide a filter capacitor at the terminals of the diode bridge.
  • the auxiliary electrode is placed between the two electrodes fed with alternating current. It delivers the rectified current, always in the same direction, to each of the aluminum electrodes. From the alternative point of view, it receives from the aluminum electrodes two currents out of phase by the sums of which cancel each other out. It is advisable to place the auxiliary electrode between the two aluminum electrodes to prevent any direct passage of alternating current between these two electrodes.
  • the diode bridge can :be switched by an inverter (not shown in the drawing) to determine the direction in which the direct current is flowing through the circuit.
  • This system of elfectively individualized circuits enables the component of each of the two types of current, alternating and direct, to be regulated with precision.
  • the present invention is applicable to the coloring of aluminum and its alloys after anodization.
  • the components to be colored can be subjected to surface treatments, such as pickling or brightening, depending upon whether it is desirable for the finished components to have a dull or bright appearance, respectively.
  • the anodizing pre-treatment is conventional and can be carried out in a sulphuric acid or chromic acid bath, under well known conditions, which result in the formation of a porous layer of alumina having a thickness within the range of 1 to 50 microns.
  • the anodized components are colored while being suspended in an acidic electrolytic bath containing metal current.
  • the treatment time depends on the current intensity and can vary from 10 seconds to 30 minutes, and preferably within the range of 1 to 10 minutes.
  • the components thus colored are sealed by approximately 30 minutes immersion in boiling water, which may optionally contain from 0.5 to 2 grams of nickel acetate per liter.
  • EXAMPLE 1 Two sheets of aluminum alloy, containing 0.6% of magnesium, which have been electrolytically brightened and anodized to a layer having a thickness of 20 microns in a sulphuric acid bath, are placed in the arrangement previously described in a bath containing 15 g./liter of copper sulphate and acidified with sulphuric acid to a pH of 1.2 and maintained at 20 C.
  • the auxiliary electrode which consists of copper, is placed between the sheets of aluminum and connected to the positive terminal of the rectified current source.
  • An alternating current of 0.6 a. etfJdm. on which a direct current of 0.1 a./dm. is superimposed is then passed through for 4 minutes.
  • a dark red color finish is obtained which, after sealing in boiling water, is resistant both to corrosion and to ultra-violet rays.
  • EXAMPLE 2 Two sheets of 99.5% pure aluminum, which have been satinized and anodized to a layer having a thickness of 15 microns in a sulphuric acid bath, are placed in a bath of copper sulphate and sulphuric acid the same as that of Example 1 with a counter electrode of copper. An alternating current of 0.6 a. eff./dm. on which a direct current of 0.2 a./dm. is superimposed, is passed through for 4 minutes with the auxiliary electrode functioning as the anode.
  • a very dark red color finish is obtained which, after the components have been sealed, is resistant both to corrosion and to ultra-violet rays.
  • EXAMPLE 3 Two sheets of aluminum alloy, containing 6% of magnesium, which have been satinized and anodized to a layer having a thickness of 10 microns in a sulphuric aicd bath, are placed in a bath which is the same as that of Example 1 maintained at 20 C., with a stainless steel counter electrode. An alternating current of 0.6 a. elf/dm. on which a direct current of 0.3 a./dm. is superimposed is passed through for 4 minutes, the auxiliary electrode acting :as the anode.
  • a black color finish is obtained which, after the components have been scaled, is resistant to corrosion and to ultra-violet rays.
  • EXAMPLE 4 Two sheets of an aluminum alloy containing 99.5% of aluminum, which have been chemically brightened and anodized to a layer thickness of microns in a sulphuric acid bath, are placed in a bath identical with that of Example 1, maintained at C., with a stainless steel counter electrode. An alternating current of 0.6 a. etfJdm. on which a direct current of 0.3 a./dm. is superimposed is then passed through for 30 seconds, the auxiliary electrode acting as the cathode.
  • a very clear reddish-copper color finish is obtained which, after the components have been sealed, is resistant to corrosion and to ultra-violet rays.
  • EXAMPLE 5 Two pieces of sections of an aluminum alloy, containing 0.5% of silicon and 0.5% of magnesium, which have been mechanically polished and anodized to a layer thick ness of 18 microns in a sulphuric acid bath, are placed in a bath containing 100 g./liter of nickel sulphate, g./liter of boric acid and g./liter of ammonium sulphate, with the bath maintained at 20 C. and with a counter electrode of nickel. An alternating current of 0.4 a. elfJdm. on which a direct current of 0.1 a./dm. is superimposed is then passed through for 4 minutes, the auxiliary electrode acting as the cathode.
  • a clear bronze color finish is obtained which, after sealing in boiling water, is resistant both to corrosion and to ultra-violet rays.
  • EXAMPLE 6 Two pieces of sections of an aluminum alloy containing 0.5 of silicon and 0.5 of magnesium, which have been satinized and anodized to a layer thickness of 12 microns in a sulphuric acid bath, are placed in a bath identical with that of Example 5, maintained at 20 C., and with a counter electrode of nickel. An alternating current of 0.4 a. elf./dm. on which a direct current of 0.3 a./dm. is superimposed is then passed through for a period of 4 minutes, the auxiliary electrode acting as the anode.
  • a dark bronze color finish is obtained which, after sealing in boiling water, is resistant to corrosion and to ultra-violet rays.
  • EXAMPLE 7 Two plates of an aluminum alloy containing 0.6% of magnesium, which have been chemically brightened and anodized to a layer thickness of 8 microns in a bath containing 50 g./liter of chromic acid, maintained at 50 C., for 50 minutes as 50 volts, are placed in a sulphuric acidcopper sulphate bath the same as that of Example 1, maintained at 20 C., with a counter electrode of copper. An alternating current of 0.6 a. efL/dm. on which a direct current of 0.3 a./dm. is superimposed is then passed through for 2 minutes, the auxiliary electrode being the cathode.
  • a copper-pink color finish is obtained, which, after the plates have been sealed for 30 minutes in boiling distilled water, is resistant to corrosion and to ultra-violet rays.
  • a process for coloring aluminum and alloys of aluminum provided with a porous oxide layer
  • the improvement comprising immersing the surface of an anodized aluminum or alloy of aluminum as an electrode in an electrolysis bath formed of an aqueous acid solution containing a dissolved salt of a metal selected from the group consisting of copper, nickel, cobalt, cadmium, silver and manganese, using a counter-electrode made of a metal of said salt or of stainless steel and passing an alternating current superimposed with a direct current through the bath, the DC/AC current density ratio being within the range of to /4.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Electroplating Methods And Accessories (AREA)
  • Electrochemical Coating By Surface Reaction (AREA)
  • Chemical Treatment Of Metals (AREA)
  • Printing Plates And Materials Therefor (AREA)
  • Electroplating And Plating Baths Therefor (AREA)
  • Electrolytic Production Of Metals (AREA)
US54878A 1969-07-16 1970-07-15 Method for electrochemical coloring of aluminum and alloys Expired - Lifetime US3704209A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR6924138A FR2052100A5 (nl) 1969-07-16 1969-07-16

Publications (1)

Publication Number Publication Date
US3704209A true US3704209A (en) 1972-11-28

Family

ID=9037497

Family Applications (1)

Application Number Title Priority Date Filing Date
US54878A Expired - Lifetime US3704209A (en) 1969-07-16 1970-07-15 Method for electrochemical coloring of aluminum and alloys

Country Status (12)

Country Link
US (1) US3704209A (nl)
JP (1) JPS4929057B1 (nl)
BE (1) BE753511A (nl)
CA (1) CA950854A (nl)
CH (1) CH501735A (nl)
DE (1) DE2034950C3 (nl)
ES (1) ES381805A1 (nl)
FR (1) FR2052100A5 (nl)
GB (1) GB1311972A (nl)
LU (1) LU61335A1 (nl)
NL (1) NL7010441A (nl)
YU (1) YU35629B (nl)

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3878056A (en) * 1973-08-24 1975-04-15 Sumitomo Chemical Co Process for electrolytic coloring of the anodic oxide film on a aluminum or aluminum base alloys
US3909367A (en) * 1973-02-23 1975-09-30 Pechiney Aluminium Method for creating a polychrome motif on an object made of aluminum or aluminum alloy
US3929593A (en) * 1973-09-21 1975-12-30 Riken Light Metal Ind Company Method of forming colored oxide film on aluminum or aluminum alloy material
US4043880A (en) * 1975-07-24 1977-08-23 Sumitomo Aluminum Smelting Co., Ltd. Method for producing green-colored anodic oxide film on aluminum or aluminum base alloy articles
US4442829A (en) * 1977-06-14 1984-04-17 Sumitomo Aluminium Smelting Company, Ltd. Material for selective absorption of solar energy and production thereof
US4632735A (en) * 1979-07-04 1986-12-30 Empresa Nacional Del Aluminio, S.A. Process for the electrolytic coloring of aluminum or aluminum alloys
US4808280A (en) * 1986-04-01 1989-02-28 Fujisash Company Method for electrolytic coloring of aluminim or aluminum alloys
US4915801A (en) * 1986-07-23 1990-04-10 Henkel Kommanditgesellschaft Auf Aktien Process for the electrolytic coloring of anodized aluminum surfaces
AU642328B2 (en) * 1991-04-11 1993-10-14 Novamax Technologies Holdings Inc. Improvements to current generation and control systems for electrolytic processes
US7276293B1 (en) * 2000-05-24 2007-10-02 Fujikura Ltd. Far-infrared radiator and method for producing method
US20100183869A1 (en) * 2009-01-16 2010-07-22 Alcoa Inc. Aluminum alloys, aluminum alloy products and methods for making the same
CN102839409A (zh) * 2012-09-07 2012-12-26 佛山市三水凤铝铝业有限公司 一种消除铝型材锡-镍双盐电解着色色差的方法
CN105386111A (zh) * 2015-11-05 2016-03-09 深圳市鑫鸿达清洗技术有限公司 一种铝合金电解着色中国红的方法

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5334107B2 (nl) * 1974-04-23 1978-09-19
DE3743113A1 (de) * 1987-12-18 1989-06-29 Gartner & Co J Verfahren zum elektrolytischen faerben von anodisch erzeugten oxidschichten auf aluminium und aluminiumlegierungen

Cited By (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3909367A (en) * 1973-02-23 1975-09-30 Pechiney Aluminium Method for creating a polychrome motif on an object made of aluminum or aluminum alloy
US3878056A (en) * 1973-08-24 1975-04-15 Sumitomo Chemical Co Process for electrolytic coloring of the anodic oxide film on a aluminum or aluminum base alloys
US3929593A (en) * 1973-09-21 1975-12-30 Riken Light Metal Ind Company Method of forming colored oxide film on aluminum or aluminum alloy material
US4043880A (en) * 1975-07-24 1977-08-23 Sumitomo Aluminum Smelting Co., Ltd. Method for producing green-colored anodic oxide film on aluminum or aluminum base alloy articles
US4442829A (en) * 1977-06-14 1984-04-17 Sumitomo Aluminium Smelting Company, Ltd. Material for selective absorption of solar energy and production thereof
US4632735A (en) * 1979-07-04 1986-12-30 Empresa Nacional Del Aluminio, S.A. Process for the electrolytic coloring of aluminum or aluminum alloys
US4808280A (en) * 1986-04-01 1989-02-28 Fujisash Company Method for electrolytic coloring of aluminim or aluminum alloys
US4992155A (en) * 1986-07-23 1991-02-12 Henkel Kommanditgesellschaft Auf Aktien Circuitry for the electrolytic coloring of anodized aluminum surfaces
US4915801A (en) * 1986-07-23 1990-04-10 Henkel Kommanditgesellschaft Auf Aktien Process for the electrolytic coloring of anodized aluminum surfaces
AU642328B2 (en) * 1991-04-11 1993-10-14 Novamax Technologies Holdings Inc. Improvements to current generation and control systems for electrolytic processes
US7276293B1 (en) * 2000-05-24 2007-10-02 Fujikura Ltd. Far-infrared radiator and method for producing method
US20100183869A1 (en) * 2009-01-16 2010-07-22 Alcoa Inc. Aluminum alloys, aluminum alloy products and methods for making the same
US8349462B2 (en) * 2009-01-16 2013-01-08 Alcoa Inc. Aluminum alloys, aluminum alloy products and methods for making the same
US8950465B2 (en) 2009-01-16 2015-02-10 Alcoa Inc. Aluminum alloys, aluminum alloy products and methods for making the same
CN102839409A (zh) * 2012-09-07 2012-12-26 佛山市三水凤铝铝业有限公司 一种消除铝型材锡-镍双盐电解着色色差的方法
CN102839409B (zh) * 2012-09-07 2015-07-22 佛山市三水凤铝铝业有限公司 一种消除铝型材锡-镍双盐电解着色色差的方法
CN105386111A (zh) * 2015-11-05 2016-03-09 深圳市鑫鸿达清洗技术有限公司 一种铝合金电解着色中国红的方法
CN105386111B (zh) * 2015-11-05 2018-07-13 深圳市鑫鸿达清洗技术有限公司 一种铝合金电解着色中国红的方法

Also Published As

Publication number Publication date
ES381805A1 (es) 1973-04-01
YU35629B (en) 1981-04-30
JPS4929057B1 (nl) 1974-08-01
FR2052100A5 (nl) 1971-04-09
DE2034950A1 (de) 1971-06-09
DE2034950C3 (de) 1973-12-06
NL7010441A (nl) 1971-01-19
DE2034950B2 (de) 1973-05-10
BE753511A (fr) 1971-01-15
YU178870A (en) 1980-10-31
CA950854A (en) 1974-07-09
CH501735A (fr) 1971-01-15
LU61335A1 (nl) 1971-07-13
GB1311972A (en) 1973-03-28

Similar Documents

Publication Publication Date Title
US3704209A (en) Method for electrochemical coloring of aluminum and alloys
CA1039228A (en) Method of forming colored oxide film on aluminum or aluminum alloy material
US3669856A (en) Process for the production of colored protective coatings on articles of aluminum or aluminum alloys
DK144481B (da) Fremgangsmaade og farveelektrolyt til farvning af forinden ved anodisering frembragte beskyttelseslag paa aluminium eller aluminiumlegeringer
US3878056A (en) Process for electrolytic coloring of the anodic oxide film on a aluminum or aluminum base alloys
US3915813A (en) Method for electrolytically coloring aluminum articles
JPH05125589A (ja) 陽極酸化されたアルミニウムを着色するための改良された電解方法
US3795590A (en) Process for coloring aluminum and alloys of aluminum having an anodized surface
US3664932A (en) Objects of aluminum and alloys of aluminum having colored coatings and process
US4226680A (en) Process for electrolytic coloration of anodized aluminium
US3704210A (en) Process for coloring aluminum objects
US3788956A (en) Electrolytic coloring of anodized aluminum
US3751350A (en) Process for coloring an aluminum anodic oxide film
SE409336B (sv) Forfarande for anodisering och anslutande elektrolytisk infergning av det bildade oxidskiktet hos en aluminiumbana medelst vexelstrom i en kontinuerlig genomdragsprocess
US3929612A (en) Process for electrolytically coloring the anodically oxidized coating on aluminum or aluminum base alloys
GB2053972A (en) Electrolytic colouring of anodized aluminium
JPS59185799A (ja) 陽極酸化物被覆の電解着色方法
JPS59190389A (ja) アルミニウムまたはアルミニウム合金の着色方法
JPS5810000A (ja) アルミニウムまたはアルミニウム合金の着色法
JPS644598B2 (nl)
SE458207B (sv) Foerfarande foer elektrofaergning av aluminium eller en legering daerav
KR890001830B1 (ko) 알루미늄 또는 그 합금의 양극산화피막의 전해착색 방법
JPS5847475B2 (ja) アルミニウム又はアルミニウム合金の着色方法
CA1038327A (en) Method of forming colored oxide film on aluminum or aluminum alloy
JPS63223199A (ja) アルミニウム材の電解着色法