US3899400A - Surface treatment of aluminum and its alloys - Google Patents

Surface treatment of aluminum and its alloys Download PDF

Info

Publication number
US3899400A
US3899400A US486741A US48674174A US3899400A US 3899400 A US3899400 A US 3899400A US 486741 A US486741 A US 486741A US 48674174 A US48674174 A US 48674174A US 3899400 A US3899400 A US 3899400A
Authority
US
United States
Prior art keywords
aluminum
lizardskin
electrode
liter
acid
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
US486741A
Other languages
English (en)
Inventor
Jos Patrie
Jacques Lefebvre
Francois Allegret
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.)
Produits Chimiques Ugine Kuhlmann
Ugine Kuhlmann SA
Original Assignee
Ugine Kuhlmann SA
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 Ugine Kuhlmann SA filed Critical Ugine Kuhlmann SA
Application granted granted Critical
Publication of US3899400A publication Critical patent/US3899400A/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
    • C25F—PROCESSES FOR THE ELECTROLYTIC REMOVAL OF MATERIALS FROM OBJECTS; APPARATUS THEREFOR
    • C25F3/00—Electrolytic etching or polishing
    • C25F3/02—Etching
    • C25F3/04—Etching of light metals

Definitions

  • ABSTRACT The surface of a piece of aluminum or aluminum alloy is decorated with a novel lizardskin appearance by passing an alternating electrolytic current at 5 to 50 volts between said piece used as an electrode, and a second electrode, both electrodes being submerged in an aqueous electrolyte bath containing 0.1 to 20 grams/liter of a suitable acid and 0.1 to 20 grams/liter of a polyfluorinated sulfonate surfactant.
  • the present invention relates to a novel method for surface treatment of aluminum and aluminum alloys, which method obtains in a simple manner a new decorative effect. This invention relates also to the aluminum objects obtained according to the new method.
  • the present invention relates to a simple means of obtaining a novel decorative appearance identified herein as lizardskin, whereby the aluminum or aluminum alloy surface is covered with scales which can be varied in size from about I to mm average diameter.
  • scales which can be varied in size from about I to mm average diameter.
  • the method of the present invention comprises placing a piece of aluminum or aluminum alloy as one electrode, together with a second electrode, in an aqueous electrolytic bath containing between 0.1 and grams per liter of a suitable acid and between 0.1 and 20 grams per liter of a polyfluorinated sulfonate surfactant; and passing an alternating electrolytic current of industrial frequency between said electrodes at a potential from about 5 to 50 volts.
  • the present relates also to pieces of aluminum treated by this method and having the unique lizardskin appearance.
  • the method of this invention can be used to advantage on objects having a wide range of size and thickness. It is particularly useful in decorating construction sheets for covering walls, ceilings and the like and for finishing foil to be used for wrapping, packaging and similar purposes, and all decorative applications where aluminum sheets or pieces are used.
  • Electrolytic installations useful in carrying out the method of this invention are conveniently of the type commonly used for graining aluminum and its alloys, for example in the preparation of lithographic plates.
  • the aqueous bath in which the electrodes are submerged can comprise any suitable acid such as hydrochloric acid, nitric acid, boric acid, fluoboric acid, or any acid which in the conditions of the treatment, does not form on the aluminum piece a protective layer of anodic oxide i.e. any acid or salt which, in the absence of the polyfluorinated surfactant, would give an anodic dissolution.
  • Sulfuric acid and chromic acid are not thus suitable in the compositions of this invention containing also fluorinated surfactants.
  • the concentration of acid useful in the electrolyte baths of this invention is in the range from 0.1 to 20 grams per liter.
  • hydrochloric acid the preferred range is from 4 to 10 grams/liter; when nitric acid is used the preferred range is 6 to 10 grams/liter.
  • Electrolysis is carried out between the aluminum piece to be treated, used as one of the electrodes, and a second electrode which can be inert to the treatment conditions, as exemplarily graphite or stainless steel.
  • the second electrode also can be aluminum or an aluminum alloy identical or similar to that of the first electrode.
  • both electrodes are similar in this manner, the second electrode also is given a lizardskin appearance on the passage of an alternating current between the electrodes, but the decorative result happens only on the opposite faces of each piece.
  • the alternating potential used in carrying out the electrolytic treatment of this invention is from 5 to 50 volts, with the frequency of the industrial current used, which may be of 50 or 60 cycles. Higher potentials in the stated range, namely from 30 to 50 volts, have been found to permit more rapid operation and to produce a finer design, i.e. with smaller scales.
  • the lower range of potential, about 5 to 20 volts, on the other hand provides a less deep design but with more contrast, with the lizardskin appearance having larger scales. Contrast is here used in the photographers sense, as indicating coarse or sharp gradations of tone, especially between light and dark areas.
  • temperatures which are suitable are in the range from 5 to 60C, temperatures from 20 to 50C being most suitable.
  • the distance between the pair of electrodes in obtaining the lizardskin appearance of this invention can vary widely, being suitably from about 2 to 30 cm; and 5 to 15 cm being preferable.
  • the current density can generally be from 2 to 10 amperes per square decimeter. However, these values are not absolutely limiting. This density depends, as usual, on the other operating parameters including applied potential, temperature and electrical resistance of the bath. It has been observed that, all other conditions remaining the same, the addition of a surfactant to the acid bath causes a diminution in the current density.
  • Treatment time can exemplarily be from about a half-minute to 10 minutes, but these values are not considered to be absolutely limiting.
  • the parameters used in carrying out this decorative treatment are very similar to those used in the aforementioned electrolytic graining.
  • the usual result obtained by the conventional graining procedure is a regular and uniformly fine engraving with a color ranging from white to gray depending on the alloy.
  • the polyfluorinated anionic sulfonate surfactant used in this invention is a sulfonic acid, or corresponding water-soluble sulfonate salt, derivative of a polyfluorinated alkyl having from 6 to 18 carbon atoms.
  • the preferred surfactant has the formula C F (CH ),,SO l-l or C F (CH ),,SO M where n is 4 to 14, b is 2 or 4 and M is any cation forming a watersoluble salt, exemplarily sodium, potassium or ammonium.
  • the perfluorinated alkyl group used in preparing the preferred surfactant can be any straight-chain, branched or cyclic alkyl group having from 4 to 14 carbon atoms and having substantially all of its hydrogens replaced by fluorine.
  • said alkyl group can be nonafluoro-n-butyl, nonafluoro-isobutyl, nonafluoro-secondary butyl, nonafluorotertiary butyl, undecafluoro-n-amyl, undecafluoro-isoamyl, undecafluoro-tertiary amyl, tridecafiuoro-n-hexyl, undecafluorocyclohexyl, pentadecafluoroheptyl, heptadecafluoro-octyl, heptadecafluoro-2-ethyl hexyl, nonadecafluorononyl, perfluorodecyl (
  • the aluminum or aluminum alloy objects to be treated by the method of this invention should be submitted to a preliminary degreasing to remove industrial forming oils which are usually found remaining on the metal.
  • the conventional solvents and/or detergents can be used.
  • the method of this invention can be applied satisfactorily on substrates which have had such a simple degreasing.
  • the degree of cleaning necessary for a particular commercial batch of substrate material can be evaluated by preliminary experiments. In some cases, as in Example 12 below, material whose past history is not completely known may be used directly without further cleaning.
  • the surface of aluminum, or an aluminum alloy, which has been given the characteristic lizardskin decoration of this invention can be submitted to an anodization without destroying the lizardskin design.
  • the lizardskin surface can also be protected by the application of a clear varnish.
  • Such after-treatments can be non-colored as in the case of an anodization without dyestuff or the application of a non-colored varnish.
  • the after-treatment can also include a coloring component and/or step, such as a conventional chemical or electrochemical treatment changing the color of the surface.
  • a coloring step can be preceded by a non-coloring anodization step.
  • transparent varnishes containing colored materials can be applied.
  • EXAMPLE 1 20C current density was fixed at 1.2 amperes per square decimeter of the plate. After treatment for 1 minute, the plate was washed with water and allowed to dry.
  • Example 2 The procedure of Example 1 was repeated except that the bath contained 8 grams/liter of hydrochloric acid (HCl) instead of the nitric acid and the current density was changed to 2.4 amperes per square decimeter. An analogous effect was obtained as in Example 1 except that the contrast was a little more marked.
  • HCl hydrochloric acid
  • EXAMPLE 3 The same conditions as in Example 2 were used except that the temperature was 30C and the current density was 2.5 amperes per square decimeter. The attained effect was similar to that of Examples 1 and 2 except that the color was in general a little darker and had more contrast; the scales of the lizardskin had a somewhat larger individual surface.
  • EXAMPLE 4 The same conditions as in Example 2 were used except that the temperature was 40C and the current density was 2.6 amperes per square decimeter. The effect was very similar to that of Example 2; the scales, however, were more marked.
  • EXAMPLE 5 The same conditions as in Example 2 were used except that the plate was an alloy of aluminum containing 0.6 of magnesium'and the applied potential was 15 The bath was an aqueous hydrochloric acid solution containing 4.4 grams/liter of HCl and] gram/liter of c m cu cn so n.
  • the plateto be treated and the other electrode were both made from aluminum designated as type A in French practice, i.e. an aluminum of purity at least equal to 99.5 Al.
  • the applied alternating potential was 18 volts of 50 cycles frequency, the temperature was C, the current density was 3.8 amperes/dm
  • the appearance obtained was of very light gray tint with very small scales.
  • EXAMPLE 8 A plate of aluminum alloy containing 1 manganese was subjected successively to two operations according to this invention. The first was carried out in a bath containing 7 grams/liter of nitric acid HNO and l gram/liter of C F CH CH SO H with the second electrode being of graphite. Applied potential was volts, bath temperature was 20C, current density was 1.2 amperes/dm the treatment lasted seconds.
  • the same plate was placed in a hydrochloric acid bath containing 8 grams/liter of HCl and 1 gram/liter of C F, Cl-I CH SO H.
  • the second electrode again was graphite.
  • the alternating current was applied at a potential of 10 volts, the temperature was 30C, current density was 2.5 amperesldm the duration of the treatment was for 1 minute.
  • EXAMPLE 9 The same conditions were used as in Example 7, except that the current was passed for an extended period of 4 minutes. After washing and rinsing, the plate was anodized by conventional anodizing techniques to a thickness of 9 microns in a sulfuric acid bath of 200 i 10 gram/liter of H 50 at 20C with a current density of 1,5 A/dm then dyed black in a bath containing nickel by the procedure described in the French Pat. No. 2,142,828. There was obtained a black colored plate on which the most brilliant points of the lizardskin configuration were distinguishable in the ground coat.
  • EXAMPLE 10 A plate obtained according to the procedure of Example 7 was covered with a clear varnish. ltwas observed that the appearance obtained according to this invention was not modified by the varnish.
  • EXAMPLE 12 Usingan electrolytic cell capable of accomodating a sheet '2 X 1 meters in area, the cell was filled with an aqueous hydrochloric acid solution containing 8 gram/- liter of HCl and l gramfliter of C FQCH CH SO 'H. A sheet of the stated size, made of an aluminum-alloy containing 1 of manganese, wasus'ed as one electrode, the other electrode being a series of graphite bars. Treatment for a period of 2 minutes was carried out with an alternating current of 50 cycles frequency, having a current density equal to 3.8 amperes per dm at a potential of 10 volts. The temperature was maintained at 30C.
  • the moving band acting as one of the electrodes in this example had a thickness of 0.8 mm, was made of an aluminum alloy containing 1 of manganese, and moved at a rate of 3 meters/minute while the other electrode, a series of graphite bars, remained in place.
  • the resulting surface had a light-gray appearance with lizardskin scales having a generally large individual area.
  • EXAMPLE 1 4 The procedure of Example 13 is repeated except that in place of the inert graphite bars, a second moving aluminum band is used, travelling at the same speed. Both bands of aluminum are given a similar lizardskin appearance on the faces of the bands which are opposite.
  • EXAMPLE 15 The procedure of Example 2 is followed in a series of 24 experiments in which the 1 gram/liter of C 1 liter, 1 gram/liter, 1O gram/liter and 20 gram/liter respectively of each of the following substances:
  • a method of decorating the surface of a piece of aluminum or aluminum alloy with a lizardskin appearance comprises placing said piece as one electrode together with a second electrode in an aqueous electrolytic bath at about 60C and containing from about 0.1 to grams/liter of hydrochloric acid, nitric acid, boric acid or fluoroboric acid and from about 0.1 to 20 grams/liter of a polyfluorinated sulfonate surfactant; and passing an alternating electrolytic current of 5060 cycles between said electrodes at a potential from about 5 to 50 volts.
  • polyfluorinated sulfonate surfactant is C F (Cl-l SO Q, wherein n is 4 to 14, b is 2 or 4, and Q is H or any cation forming a water-soluble salt.
  • the second electrode also is a piece of aluminum or aluminum alloy, whereby the opposite surfaces of both electrodes are decorated with the lizardskin appearance.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Engineering & Computer Science (AREA)
  • Cleaning And De-Greasing Of Metallic Materials By Chemical Methods (AREA)
  • Electrochemical Coating By Surface Reaction (AREA)
  • ing And Chemical Polishing (AREA)
  • Electroplating And Plating Baths Therefor (AREA)
  • Chemical Treatment Of Metals (AREA)
  • Printing Plates And Materials Therefor (AREA)
  • Application Of Or Painting With Fluid Materials (AREA)
  • Electroplating Methods And Accessories (AREA)
US486741A 1973-07-13 1974-07-09 Surface treatment of aluminum and its alloys Expired - Lifetime US3899400A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR7325800A FR2241633B1 (de) 1973-07-13 1973-07-13

Publications (1)

Publication Number Publication Date
US3899400A true US3899400A (en) 1975-08-12

Family

ID=9122562

Family Applications (1)

Application Number Title Priority Date Filing Date
US486741A Expired - Lifetime US3899400A (en) 1973-07-13 1974-07-09 Surface treatment of aluminum and its alloys

Country Status (11)

Country Link
US (1) US3899400A (de)
JP (1) JPS5439816B2 (de)
BE (1) BE816417A (de)
BR (1) BR7405759D0 (de)
CA (1) CA1050479A (de)
CH (1) CH586289A5 (de)
DE (1) DE2433491C3 (de)
FR (1) FR2241633B1 (de)
GB (1) GB1427909A (de)
IT (1) IT1014404B (de)
NL (1) NL176693C (de)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4233107A (en) * 1979-04-20 1980-11-11 The United States Of America As Represented By The Secretary Of Commerce Ultra-black coating due to surface morphology
US4361630A (en) * 1979-04-20 1982-11-30 The United States Of America As Represented By The Secretary Of The Commerce Ultra-black coating due to surface morphology
US4600482A (en) * 1984-04-25 1986-07-15 Hoechst Aktiengesellschaft Process for the electrochemical roughening of aluminum for use as printing plate supports, in an aqueous mixed electrolyte
US20190177871A1 (en) * 2016-12-02 2019-06-13 Pacesetter, Inc. Use Of Nonafluorobutanesulfonic Acid In A Low PH Etch Solution To Increase Aluminum Foil Capacitance

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3400250A1 (de) * 1984-01-05 1985-07-18 Hoechst Ag, 6230 Frankfurt Verfahren zur elektrochemischen aufrauhung von aluminium fuer druckplattentraeger in einem waessrigen mischelektrolyten
DE3400249A1 (de) * 1984-01-05 1985-07-18 Hoechst Ag, 6230 Frankfurt Verfahren zur elektrochemischen aufrauhung von aluminium fuer druckplattentraeger in einem waessrigen mischelektrolyten
DE3400248A1 (de) * 1984-01-05 1985-07-18 Hoechst Ag, 6230 Frankfurt Verfahren zur elektrochemischen aufrauhung von aluminium fuer druckplattentraeger in einem waessrigen mischelektrolyten

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2750337A (en) * 1953-04-22 1956-06-12 Udylite Res Corp Electroplating of chromium
US2871425A (en) * 1954-09-16 1959-01-27 Fansteel Metallurgical Corp Capacitor
US2941930A (en) * 1957-05-28 1960-06-21 Reynolds Metals Co Decorative aluminum surface
US3073765A (en) * 1960-04-18 1963-01-15 Adams Ronald Alfred Charles Process for electrolytically graining aluminum lithographic plates
US3755116A (en) * 1971-04-17 1973-08-28 Sumitomo Light Metal Ind Process for the production of aluminum base offset printing plates

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2750337A (en) * 1953-04-22 1956-06-12 Udylite Res Corp Electroplating of chromium
US2871425A (en) * 1954-09-16 1959-01-27 Fansteel Metallurgical Corp Capacitor
US2941930A (en) * 1957-05-28 1960-06-21 Reynolds Metals Co Decorative aluminum surface
US3073765A (en) * 1960-04-18 1963-01-15 Adams Ronald Alfred Charles Process for electrolytically graining aluminum lithographic plates
US3755116A (en) * 1971-04-17 1973-08-28 Sumitomo Light Metal Ind Process for the production of aluminum base offset printing plates

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4233107A (en) * 1979-04-20 1980-11-11 The United States Of America As Represented By The Secretary Of Commerce Ultra-black coating due to surface morphology
US4361630A (en) * 1979-04-20 1982-11-30 The United States Of America As Represented By The Secretary Of The Commerce Ultra-black coating due to surface morphology
US4600482A (en) * 1984-04-25 1986-07-15 Hoechst Aktiengesellschaft Process for the electrochemical roughening of aluminum for use as printing plate supports, in an aqueous mixed electrolyte
US20190177871A1 (en) * 2016-12-02 2019-06-13 Pacesetter, Inc. Use Of Nonafluorobutanesulfonic Acid In A Low PH Etch Solution To Increase Aluminum Foil Capacitance
US11230794B2 (en) * 2016-12-02 2022-01-25 Pacesetter, Inc. Use of nonafluorobutanesulfonic acid in a low PH etch solution to increase aluminum foil capacitance

Also Published As

Publication number Publication date
CH586289A5 (de) 1977-03-31
JPS5043022A (de) 1975-04-18
BE816417A (fr) 1974-10-16
DE2433491A1 (de) 1975-01-30
NL7409460A (nl) 1975-01-15
NL176693C (nl) 1985-05-17
CA1050479A (fr) 1979-03-13
FR2241633B1 (de) 1976-06-18
DE2433491B2 (de) 1977-10-13
GB1427909A (en) 1976-03-10
DE2433491C3 (de) 1978-06-01
BR7405759D0 (pt) 1975-05-20
NL176693B (nl) 1984-12-17
IT1014404B (it) 1977-04-20
FR2241633A1 (de) 1975-03-21
JPS5439816B2 (de) 1979-11-30

Similar Documents

Publication Publication Date Title
CA1046975A (en) Process for electrolytic colouring of the anodic oxide film on aluminum or aluminum base alloys
US3980539A (en) Process for electrolytic graining of aluminum
CA1059059A (en) Producing a coloured oxide on an article of aluminium or aluminium alloy
US3899400A (en) Surface treatment of aluminum and its alloys
US3878056A (en) Process for electrolytic coloring of the anodic oxide film on a aluminum or aluminum base alloys
US3769180A (en) Process for electrolytically coloring previously anodized aluminum using alternating current
US3773631A (en) Aqueous electrolytic bath for coloring anodic oxide layers on aluminum and aluminum alloy substrates and process for coloring said substrates
KR860001286B1 (ko) 알루미늄 표면에 착색 주름무늬를 형성하는 방법
JPS58177494A (ja) アルミニウム被覆部品の陽極酸化浴および陽極酸化方法
JP4223088B2 (ja) 金属素地の光沢を呈する耐食性マグネシウム材料製品及びその製造方法
US4180443A (en) Method for coloring aluminum
US4430169A (en) Method of producing green coatings on aluminum and aluminum alloys
JPS63312998A (ja) 陽極酸化アルミニウムの電解着色
US3704210A (en) Process for coloring aluminum objects
US4201836A (en) Aluminum substrates grained with a saturated solution of aluminum salts of mineral acids
US3365380A (en) Electrolytic polishing solution and the process of polishing therewith
US3929612A (en) Process for electrolytically coloring the anodically oxidized coating on aluminum or aluminum base alloys
CA1074725A (en) Process for electrolytically coloring aluminum and aluminum alloys
DE2537725B2 (de) Verwendung eines Verfahrens zum elektrochemischen Aufrauhen von Aluminium bei der Herstellung von Flachdruckplattenträgern
US3658665A (en) Electrolytic method for producing a colored anodized layer on aluminum and alloys of aluminum
EP0015279A1 (de) Beschichtungs-system.
US2752305A (en) Processes of electrolytic polishing of metals
SU802409A1 (ru) Способ окрашивани изделий изАлюМиНи и ЕгО СплАВОВ
Keller Coloring Anodically Oxidized Aluminum
JPH0472099A (ja) 印刷版用アルミニウム支持体の製造方法