US3729391A - Surface treatment of zinc/aluminium alloys - Google Patents
Surface treatment of zinc/aluminium alloys Download PDFInfo
- Publication number
- US3729391A US3729391A US00224979A US3729391DA US3729391A US 3729391 A US3729391 A US 3729391A US 00224979 A US00224979 A US 00224979A US 3729391D A US3729391D A US 3729391DA US 3729391 A US3729391 A US 3729391A
- Authority
- US
- United States
- Prior art keywords
- minutes
- zinc
- alloy
- voltage
- aluminium
- 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
Links
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 title abstract description 39
- 239000011701 zinc Substances 0.000 title abstract description 39
- 238000004381 surface treatment Methods 0.000 title abstract description 6
- 229910000838 Al alloy Inorganic materials 0.000 title description 11
- 229910001297 Zn alloy Inorganic materials 0.000 title description 8
- 229910052725 zinc Inorganic materials 0.000 abstract description 32
- 229910052782 aluminium Inorganic materials 0.000 abstract description 23
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 abstract description 22
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 abstract description 15
- 238000000034 method Methods 0.000 abstract description 15
- 239000001117 sulphuric acid Substances 0.000 abstract description 15
- 235000011149 sulphuric acid Nutrition 0.000 abstract description 15
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 abstract description 6
- 229910052749 magnesium Inorganic materials 0.000 abstract description 6
- 239000011777 magnesium Substances 0.000 abstract description 6
- 229910052751 metal Inorganic materials 0.000 abstract description 5
- 239000002184 metal Substances 0.000 abstract description 5
- 230000003647 oxidation Effects 0.000 abstract description 4
- 238000007254 oxidation reaction Methods 0.000 abstract description 4
- 229910045601 alloy Inorganic materials 0.000 description 53
- 239000000956 alloy Substances 0.000 description 53
- 239000004411 aluminium Substances 0.000 description 21
- 238000007743 anodising Methods 0.000 description 10
- PNEYBMLMFCGWSK-UHFFFAOYSA-N Alumina Chemical compound [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 9
- 230000002045 lasting effect Effects 0.000 description 7
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 6
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 5
- 229910052802 copper Inorganic materials 0.000 description 5
- 239000010949 copper Substances 0.000 description 5
- 238000005260 corrosion Methods 0.000 description 5
- 230000007797 corrosion Effects 0.000 description 5
- 238000007789 sealing Methods 0.000 description 4
- 239000000243 solution Substances 0.000 description 4
- 238000011282 treatment Methods 0.000 description 4
- 241000220317 Rosa Species 0.000 description 3
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 3
- 238000010186 staining Methods 0.000 description 3
- XLOMVQKBTHCTTD-UHFFFAOYSA-N Zinc monoxide Chemical compound [Zn]=O XLOMVQKBTHCTTD-UHFFFAOYSA-N 0.000 description 2
- 238000009835 boiling Methods 0.000 description 2
- 239000012153 distilled water Substances 0.000 description 2
- 239000003792 electrolyte Substances 0.000 description 2
- 238000001704 evaporation Methods 0.000 description 2
- 230000008020 evaporation Effects 0.000 description 2
- 238000002386 leaching Methods 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 230000000630 rising effect Effects 0.000 description 2
- 150000003839 salts Chemical class 0.000 description 2
- CDBYLPFSWZWCQE-UHFFFAOYSA-L sodium carbonate Substances [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 2
- 241001163841 Albugo ipomoeae-panduratae Species 0.000 description 1
- 238000007792 addition Methods 0.000 description 1
- 230000001464 adherent effect Effects 0.000 description 1
- 238000005275 alloying Methods 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000005266 casting Methods 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 229910000029 sodium carbonate Inorganic materials 0.000 description 1
- 239000011787 zinc oxide Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C18/00—Alloys based on zinc
- C22C18/04—Alloys based on zinc with aluminium as the next major constituent
-
- 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
- C25D11/34—Anodisation of metals or alloys not provided for in groups C25D11/04 - C25D11/32
Definitions
- a method for the surface treatment of an alloy consisting predominantly of zinc and aluminium, and containing 60-85% by weight of zinc by immersing a surface of the alloy in dilute aqueous sulphuric acid, comprising subjecting the alloy to anodic oxidation at a current density of from 50 to 200 milliamperes per square centimetre of surface.
- the alloy may include up to 0.5% by weight of copper or magnesium as a third metal.
- This invention relates to the surface treatment of zinc/ aluminium alloys to produce thereon a protective and/ or decorative surface finish.
- aluminium alloys containing a few percent of zinc by Weight can be anodised in a 15% solution by weight of sulphuric acid to produce aluminium oxide films containing zinc values in approximately the alloying proportions. It has been found impossible to anodise zinc in any sulphuric acid solution or a 55/45 zinc/aluminium alloy in 4 N sulphuric acid solution at a current density of 10 ma./ sq.
- the invention consists in a method for the surface treatment of an alloy consisting predominantly of zinc and aluminium, and contaiining 60-85% by weight of zinc, comprising immersing a surface of the alloy in dilute aqueous sulphuric acid and subjecting it to anodic oxidation at a current density of from 50 to 200 milliamperes per square centimetre of the surface.
- zinc/aluminium alloys containing 60-85% by weight of zinc may be anodically oxidised in aqueous solutions of sulphuric acid to produce films which are basically aluminium oxide with only a small content of zinc, probably as oxide, of about 510% by weight of the anodised film.
- sulphuric acid aqueous solutions of sulphuric acid
- this film confers corrosion protection on the alloy and that sealing treatment of the type 3,729,391 Patented Apr. 24, 1973 "Ice applied to anodised films on aluminium also has a beneficial effect on these films.
- the alloy is usually either an alloy of high-purity zinc, or commercial-purity zinc (i.e. containing only incidental impurities, as well known to the man skilled in the art) with correspondingly high-purity or commercial-purity aluminium. While the alloy can have a composition containing up to by weight of zinc, i.e. as little as 15% by weight of aluminium, in practice it is most preferred to use compositions containing 60-80%, or even 60- 70% of zinc by weight. Although the alloys to be treated in the present method consist predominantly of zinc and aluminium it is possible to include minor amounts of a ternary metal as deliberate additions, e.g. up to 0.5% of copper or magnesium may be added.
- the microstructure of the alloy is usually that produced by casting and mechanical working, and will generally comprise alternate regions, e.g. of approximately 1,u. diameter (i.e. 10- metres) of zinc-rich and aluminium-rich phases.
- Zinc may be removed from the surface of the alloy prior to anodizing e.g. by evaporation in vacuo.
- anodizing e.g. by evaporation in vacuo.
- it is a valuable feature of the present method that by suitable control of the anodizing conditions the preferential leaching of a zinc phase and the anodizing of an aluminium-rich phase may be carried out simultaneously in the same bath of sulphuric acid.
- the sulphuric acid concentration is preferably between 1% and 40% (W./v.) and the most preferred range is between 10% and 20% (w./v.) H 80 in water.
- the anodizing is preferably carried out at a temperature within the range 030 C. Above 30 C. the anodized layer becomes less adherent.
- sealing can be effected in boiling distilled water.
- the voltage began to rise slowly after a region of very low voltage (12 V.) lasting 5 minutes, and then more steeply to give a peak of 50 v. after 25 minutes. The voltage then dropped slowly to give 15 v. after 34 minutes, and then rose slowly to give 35 v. after 60 minutes.
- ALLOY F At 150 ma./cm. alloy F exhibited a region of very low voltage (1-2 V.) lasting 2 minutes followed by a voltage rise to a plateau of 8 v. after 3 minutes. This value was maintained until a sharp rise started after 7.5 minutes to give 30 v. after 12.5 minutes. The voltage then rose more gradually to 45 v. after 22.5 minutes. At this stage a voltage surge to over 100 v. occurred at about 25 minutes. The voltage then dropped sharply to 30 v. and thereafter fluctuated gently about this value.
- the voltage rose to a platen of 4 v. after 6 minutes after an initial low voltage region of about 12 v. lasting 5 minutes. After about 16 minutes a sharp rise occurred reaching 30 v. after 22.5 minutes. The voltage then rose more gradually to about 45 v. after 35 minutes. It then dropped gradually to about 40 v. after 47.5 minutes and then more sharply to 25 v. after 50 minutes. Thereafter the voltage remained approximately at this value.
- Tests were also carried out on commercial purity zinc/ aluminium alloys containing small amounts of magnesium and copper. Two alloy samples were treated as summarised below.
- the voltage rose gradually to 3 v. after 20 minutes. This rise steepened to 30 v. after 35 minutes. The voltage then dipped to 28 v. after 42.5 minutes and rose again to 37 v. after 60 minutes.
- the voltage rose to 4 v. after 6 minutes after an initial low voltage region of 1-2 v. lasting 5 minutes. The voltage then rose increasingly sharply to give 26 v. after 25 minutes. It then rose gradually to 35 v. after 52.5 minutes and then dropped to 25 v. after 60 minutes.
- SPECIMEN FILM THICKNESS-TIME DATA The figures in the table below refer to the thickness of the anodic film (in microns) formed during anodising of Zn-22% Al at 100 ma./cm. in w./v. sulphuric acid at C. for various times.
- the alloy includes up to 0.5% by Weight of a th rd metal selected from the group consisting of copper and magnesium.
- a method as claimed in claim 1 further comprising sealing the anodized film produced in boiling distilled water.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Mechanical Engineering (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Prevention Of Electric Corrosion (AREA)
- Electroplating Methods And Accessories (AREA)
- Electrolytic Production Of Metals (AREA)
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB423171 | 1971-02-09 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US3729391A true US3729391A (en) | 1973-04-24 |
Family
ID=9773212
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US00224979A Expired - Lifetime US3729391A (en) | 1971-02-09 | 1972-02-09 | Surface treatment of zinc/aluminium alloys |
Country Status (6)
| Country | Link |
|---|---|
| US (1) | US3729391A (fr) |
| BE (1) | BE779103A (fr) |
| DE (1) | DE2204958C3 (fr) |
| GB (1) | GB1322077A (fr) |
| NL (1) | NL147794B (fr) |
| SE (1) | SE372565B (fr) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20060013986A1 (en) * | 2001-10-02 | 2006-01-19 | Dolan Shawn E | Article of manufacture and process for anodically coating an aluminum substrate with ceramic oxides prior to organic or inorganic coating |
| US20090098373A1 (en) * | 2001-10-02 | 2009-04-16 | Henkelstrasse 67 | Anodized coating over aluminum and aluminum alloy coated substrates and coated articles |
| US20090258242A1 (en) * | 2001-10-02 | 2009-10-15 | Henkel Ag & Co. Kgaa | Article of manufacture and process for anodically coating an aluminum substrate with ceramic oxides prior to polytetrafluoroethylene or silicone coating |
| US20100000870A1 (en) * | 2001-10-02 | 2010-01-07 | Henkel Ag & Co. Kgaa | Article of manufacture and process for anodically coating aluminum and/or titanium with ceramic oxides |
| CN105543936A (zh) * | 2016-01-22 | 2016-05-04 | 浙江工业大学 | 锌材阳极氧化和表面染色的方法 |
| US9701177B2 (en) | 2009-04-02 | 2017-07-11 | Henkel Ag & Co. Kgaa | Ceramic coated automotive heat exchanger components |
-
1971
- 1971-02-09 GB GB423171A patent/GB1322077A/en not_active Expired
-
1972
- 1972-02-03 DE DE2204958A patent/DE2204958C3/de not_active Expired
- 1972-02-04 NL NL727201517A patent/NL147794B/xx unknown
- 1972-02-08 BE BE779103A patent/BE779103A/fr unknown
- 1972-02-08 SE SE7201476A patent/SE372565B/xx unknown
- 1972-02-09 US US00224979A patent/US3729391A/en not_active Expired - Lifetime
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20060013986A1 (en) * | 2001-10-02 | 2006-01-19 | Dolan Shawn E | Article of manufacture and process for anodically coating an aluminum substrate with ceramic oxides prior to organic or inorganic coating |
| US20090098373A1 (en) * | 2001-10-02 | 2009-04-16 | Henkelstrasse 67 | Anodized coating over aluminum and aluminum alloy coated substrates and coated articles |
| US20090258242A1 (en) * | 2001-10-02 | 2009-10-15 | Henkel Ag & Co. Kgaa | Article of manufacture and process for anodically coating an aluminum substrate with ceramic oxides prior to polytetrafluoroethylene or silicone coating |
| US20100000870A1 (en) * | 2001-10-02 | 2010-01-07 | Henkel Ag & Co. Kgaa | Article of manufacture and process for anodically coating aluminum and/or titanium with ceramic oxides |
| US7820300B2 (en) | 2001-10-02 | 2010-10-26 | Henkel Ag & Co. Kgaa | Article of manufacture and process for anodically coating an aluminum substrate with ceramic oxides prior to organic or inorganic coating |
| US8361630B2 (en) | 2001-10-02 | 2013-01-29 | Henkel Ag & Co. Kgaa | Article of manufacture and process for anodically coating an aluminum substrate with ceramic oxides prior to polytetrafluoroethylene or silicone coating |
| US8663807B2 (en) | 2001-10-02 | 2014-03-04 | Henkel Ag & Co. Kgaa | Article of manufacture and process for anodically coating aluminum and/or titanium with ceramic oxides |
| US9023481B2 (en) * | 2001-10-02 | 2015-05-05 | Henkel Ag & Co. Kgaa | Anodized coating over aluminum and aluminum alloy coated substrates and coated articles |
| US9701177B2 (en) | 2009-04-02 | 2017-07-11 | Henkel Ag & Co. Kgaa | Ceramic coated automotive heat exchanger components |
| CN105543936A (zh) * | 2016-01-22 | 2016-05-04 | 浙江工业大学 | 锌材阳极氧化和表面染色的方法 |
Also Published As
| Publication number | Publication date |
|---|---|
| DE2204958A1 (de) | 1972-08-17 |
| BE779103A (fr) | 1972-05-30 |
| GB1322077A (en) | 1973-07-04 |
| SE372565B (fr) | 1974-12-23 |
| NL147794B (nl) | 1975-11-17 |
| DE2204958C3 (de) | 1974-08-22 |
| DE2204958B2 (de) | 1974-01-10 |
| NL7201517A (fr) | 1972-08-11 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4606796A (en) | Colored, anodized aluminum-base article and method of preparing same | |
| US3098018A (en) | Sealing anodized aluminum | |
| US2708655A (en) | Electrolytic polishing of aluminum | |
| US3961111A (en) | Method of increasing corrosion resistance of anodized aluminum | |
| US2096309A (en) | Surface treatment of aluminum and aluminum alloys | |
| US3370943A (en) | Aluminum alloy | |
| US4045599A (en) | Low temperature sealing of anodized aluminum | |
| US3729391A (en) | Surface treatment of zinc/aluminium alloys | |
| US4483750A (en) | Process for anodizing highly reflective aluminum materials | |
| CA1134774A (fr) | Anodisation de l'aluminium | |
| US3075896A (en) | Process for coating titanium articles | |
| US3328274A (en) | Method of anodizing aluminum | |
| US2339806A (en) | Surface treatment of aluminum and aluminum alloys | |
| US3531381A (en) | Method of improving the corrosion resistance of oxidized metal surfaces | |
| US3365377A (en) | Method of sealing anodized aluminum | |
| US3578570A (en) | Aluminum capacitor foil | |
| US3836439A (en) | Method for forming a colored oxide coating on surfaces of aluminum or aluminum alloy | |
| US2666023A (en) | Anodic coating of aluminum | |
| US2682503A (en) | Method and material for electrolytically brightening aluminum surfaces | |
| US2107318A (en) | White coating on aluminum | |
| US2092034A (en) | Thermal treatment of aluminous metals | |
| US3787298A (en) | Anodizing aluminum foams | |
| US2430468A (en) | Electroplating silver on aluminum and its alloys | |
| US3565772A (en) | Process for self-colored anodization of aluminum and alloys | |
| US4060462A (en) | Color anodizing of aluminum |