US20020157961A1 - Anodizing process, with low environmental impact, for a woodpiece of aluminum or aluminum alloys - Google Patents
Anodizing process, with low environmental impact, for a woodpiece of aluminum or aluminum alloys Download PDFInfo
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- US20020157961A1 US20020157961A1 US10/078,693 US7869302A US2002157961A1 US 20020157961 A1 US20020157961 A1 US 20020157961A1 US 7869302 A US7869302 A US 7869302A US 2002157961 A1 US2002157961 A1 US 2002157961A1
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- workpiece
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- aluminum
- anodizing
- acid
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Links
- 238000000034 method Methods 0.000 title claims abstract description 26
- 238000007743 anodising Methods 0.000 title claims abstract description 19
- 229910000838 Al alloy Inorganic materials 0.000 title claims abstract description 10
- 229910052782 aluminium Inorganic materials 0.000 title claims abstract description 8
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 title claims abstract description 8
- 230000007613 environmental effect Effects 0.000 title description 2
- 239000011260 aqueous acid Substances 0.000 claims abstract description 12
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims abstract description 11
- FEWJPZIEWOKRBE-JCYAYHJZSA-N Dextrotartaric acid Chemical compound OC(=O)[C@H](O)[C@@H](O)C(O)=O FEWJPZIEWOKRBE-JCYAYHJZSA-N 0.000 claims abstract description 9
- FEWJPZIEWOKRBE-UHFFFAOYSA-N Tartaric acid Natural products [H+].[H+].[O-]C(=O)C(O)C(O)C([O-])=O FEWJPZIEWOKRBE-UHFFFAOYSA-N 0.000 claims abstract description 9
- 235000011002 L(+)-tartaric acid Nutrition 0.000 claims abstract description 8
- 239000001358 L(+)-tartaric acid Substances 0.000 claims abstract description 8
- FEWJPZIEWOKRBE-LWMBPPNESA-N L-(+)-Tartaric acid Natural products OC(=O)[C@@H](O)[C@H](O)C(O)=O FEWJPZIEWOKRBE-LWMBPPNESA-N 0.000 claims abstract description 8
- 238000011282 treatment Methods 0.000 claims description 22
- 235000011149 sulphuric acid Nutrition 0.000 claims description 10
- 239000001117 sulphuric acid Substances 0.000 claims description 10
- 239000004411 aluminium Substances 0.000 claims description 6
- 238000004140 cleaning Methods 0.000 claims description 6
- 238000007789 sealing Methods 0.000 claims description 6
- 239000000243 solution Substances 0.000 description 18
- 238000000576 coating method Methods 0.000 description 11
- 239000011248 coating agent Substances 0.000 description 10
- 238000007654 immersion Methods 0.000 description 7
- KRVSOGSZCMJSLX-UHFFFAOYSA-L chromic acid Substances O[Cr](O)(=O)=O KRVSOGSZCMJSLX-UHFFFAOYSA-L 0.000 description 6
- 238000005260 corrosion Methods 0.000 description 6
- 230000007797 corrosion Effects 0.000 description 6
- AWJWCTOOIBYHON-UHFFFAOYSA-N furo[3,4-b]pyrazine-5,7-dione Chemical compound C1=CN=C2C(=O)OC(=O)C2=N1 AWJWCTOOIBYHON-UHFFFAOYSA-N 0.000 description 6
- 239000002253 acid Substances 0.000 description 5
- 239000003973 paint Substances 0.000 description 5
- 239000010935 stainless steel Substances 0.000 description 4
- 239000011975 tartaric acid Substances 0.000 description 4
- PNEYBMLMFCGWSK-UHFFFAOYSA-N Alumina Chemical compound [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 239000003651 drinking water Substances 0.000 description 3
- 235000020188 drinking water Nutrition 0.000 description 3
- 239000002699 waste material Substances 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- 150000001875 compounds Chemical class 0.000 description 2
- 230000003750 conditioning effect Effects 0.000 description 2
- 239000008367 deionised water Substances 0.000 description 2
- 229910021641 deionized water Inorganic materials 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 1
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000007767 bonding agent Substances 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 239000011651 chromium Substances 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 238000009661 fatigue test Methods 0.000 description 1
- 238000009863 impact test Methods 0.000 description 1
- 239000002440 industrial waste Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000003595 mist Substances 0.000 description 1
- 238000005554 pickling Methods 0.000 description 1
- 239000011780 sodium chloride Substances 0.000 description 1
- 235000002906 tartaric acid Nutrition 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
- 231100000331 toxic Toxicity 0.000 description 1
- 230000002588 toxic effect Effects 0.000 description 1
- 230000002110 toxicologic effect Effects 0.000 description 1
- 231100000027 toxicology Toxicity 0.000 description 1
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
- C25D11/06—Anodisation of aluminium or alloys based thereon characterised by the electrolytes used
Definitions
- the present invention relates to an anodizing process for a workpiece (such as, for example, a part or a component of a system) of aluminium or aluminium alloys, this definition being intended to comprise pure or almost pure aluminium, as well as combinations thereof in all percentages with other elements.
- a workpiece such as, for example, a part or a component of a system
- aluminium or aluminium alloys this definition being intended to comprise pure or almost pure aluminium, as well as combinations thereof in all percentages with other elements.
- this process makes use of the above-mentioned workpiece as the anode of an electrolytic cell in the presence of an aqueous acid solution in order to form on the surface of the workpiece a coating of aluminium oxide.
- This coating results in better properties concerning the resistance to corrosion and the adhesion of paints, bonding agents and other organic coatings suitable for improving the appearance or the resistance to corrosion of the finished workpiece.
- this acid solution substantially comprises sulphuric acid at high concentrations or chromic acid, the latter being the compound mainly used in the field of aeronautics.
- the problem addressed by the present invention is to provide an anodizing process having a lesser toxicological impact on the environment in comparison with the known types, avoiding the use of chromic acid whilst nevertheless obtaining anodized workpieces having properties which are at least equivalent to those of workpieces obtained by conventional means.
- the process according to the invention has the advantage of eliminating, or in any case greatly reducing, the production of industrial waste, in particular waste containing compounds of chromium, without causing the formation of other waste materials having particular toxic or dangerous properties.
- the process according to the invention further has the advantage of having a cycle time which is approximately 40% short of that of the analogous process which makes use of chromic acid, producing anodized workpieces having properties at least equivalent if not superior. Consequently, the process according to the invention allows a considerable reduction in running costs to be obtained in that it results in lower costs for the treatment of the waste and involves a substantially lower rate of consumption for the different chemicals used for replenishing the baths, which have an operational life greater than those used in known processes.
- the aqueous acid solution of the process according to the invention preferably contains from 20 to 80 g sulphuric acid and from 30 to 120 g L(+)-tartaric acid per liter of solution.
- the aqueous solution is maintained, during the anodizing treatment, at a temperature of between ambient temperature and 120° C. and, more preferably, between 25 and 35° C.
- the electrolytic cell in which the process according to the invention is carried out, is preferably subjected to a voltage of between 1 and 120 V and, more preferably, of between 10 and 30 V.
- the process according to the invention advantageously has a duration of between 5 and 120 minutes and, preferably, of between 5 and 30 minutes.
- the anodizing process is generally preceded by a cleaning and/or deoxidizing treatment of the workpiece to be anodized and can be followed by a sealing treatment and, optionally, rinsing for the anodized workpiece.
- these treatments are of conventional type and completely compatible with the present invention and can be selected at will from treatments known to this end by the person skilled in the art.
- the workpiece advantageously has, upon completion of the anodizing treatment, an oxidized surface coating having a thickness of between a few micrometers and several tens of micrometers.
- a workpiece (of a 2000-series aluminium alloy having dimensions of 150 ⁇ 100 ⁇ 1 mm) was first subjected in a conventional manner to cleaning and deoxidizing treatments, such as de- greasing by immersion for approximately 10 minutes, rinsing by immersion in drinking water for approximately 3 minutes, pickling/deoxidation by immersion for approximately 10 minutes and rinsing by immersion in drinking water, preferably followed by further rinsing by immersion in deionized water for a total of approximately 3 minutes.
- cleaning and deoxidizing treatments such as de- greasing by immersion for approximately 10 minutes, rinsing by immersion in drinking water for approximately 3 minutes, pickling/deoxidation by immersion for approximately 10 minutes and rinsing by immersion in drinking water, preferably followed by further rinsing by immersion in deionized water for a total of approximately 3 minutes.
- the workpiece was then used as the anode of an electrochemical cell, in which the cathode was constituted by corrosion-resistant steel of the type AISI 321 and having a surface area equal to or greater than that to be oxidized and in the presence of an aqueous acid solution containing 45 g sulphuric acid and 80 g L(+)-tartaric acid per liter of solution and was maintained at a temperature of between 30 and 35° C. The workpiece was kept completely immersed in the acid solution.
- the electrical voltage was increased from an initial value of 0 V to a value of 18 V at a rate in the order of 3.6 V/min.
- the final voltage value was maintained for 25 minutes, producing on the workpiece, upon completion of the anodizing treatment, an oxidized coating having a thickness of approximately 5 ⁇ m.
- the anodized workpiece was then subjected to treatments which are conventional per se, such as rinsing with drinking water, preferably followed by further rinsing with deionized water for an overall immersion time of approximately 3 minutes and sealing by immersion for approximately 45 minutes.
- treatments which are conventional per se, such as rinsing with drinking water, preferably followed by further rinsing with deionized water for an overall immersion time of approximately 3 minutes and sealing by immersion for approximately 45 minutes.
- the workpiece was then dried with air, in particular at a low temperature, if good properties of adhesiveness were required for the oxide.
- a workpiece (of a 7000-series aluminium alloy having dimensions of 150 ⁇ 100 ⁇ 1 mm) was first subjected in a conventional manner to cleaning and deoxidizing treatments, similar to those described with reference to Example 1.
- the workpiece was then used as the anode of an electrochemical cell, in which the cathode was constituted by corrosion-resistant steel of the type AISI 321 and having a surface area equal to or greater than that to be oxidized and in the presence of an aqueous acid solution containing 45 g sulphuric acid and 80 g L(+)-tartaric acid per liter of solution and was maintained at a temperature of between 30 and 35° C. The workpiece was kept completely immersed in the acid solution.
- the electrical voltage was increased from an initial value of 0 V to a value of 15 V at a rate in the order of 3 V/min.
- the final voltage value was maintained for 25 minutes, producing on the workpiece, upon completion of the anodizing treatment, an oxidized coating having a thickness of approximately 5 ⁇ m.
- a workpiece (of a plated aluminium alloy or pure aluminium having dimensions of 150 ⁇ 100 ⁇ 1 mm) was first subjected, in a conventional manner, to cleaning and deoxidizing treatments, similar to those described with reference to Example 1.
- the workpiece was then used as the anode of an electrochemical cell, in which the cathode was constituted by corrosion-resistant steel of the type AISI 321 and having a surface area equal to or greater than that to be oxidized and in the presence of an aqueous acid solution containing 45 g sulphuric acid and 80 g L(+)-tartaric acid per liter of solution and was maintained at a temperature of between 30 and 35° C. The workpiece was kept completely immersed in the acid solution.
- the electrical voltage was increased from an initial value of 0 V to a value of 15 V at a rate in the order of 3 V/min.
- the final voltage value was maintained for 25 minutes, producing on the workpiece, upon completion of the anodizing treatment, an oxidized coating having a thickness of approximately 5 ⁇ m.
- a workpiece (of a plated aluminium alloy or a pure aluminium having dimensions of 150 ⁇ 100 ⁇ 1 mm) was first subjected in a conventional manner to cleaning and deoxidizing treatments, similar to those described with reference to Example 1.
- the workpiece was then used as the anode of an electrochemical cell, in which the cathode was constituted by corrosion-resistant steel of the type AISI 321 and having a surface area equal to or greater than that to be oxidized and in the presence of an aqueous acid solution containing 65 g chromic acid and was maintained at a temperature of between 35 and 40° C.
- the workpiece was kept completely immersed in the acid solution.
- the electrical voltage was increased from an initial value of 0 V to a value of 40 V at a rate in the order of 5 V/min.
- the final voltage value was maintained for 45 minutes, producing on the workpiece, upon completion of the anodizing treatment, an oxidized coating having a thickness of approximately 3 ⁇ m.
- aqueous acid solution could contain, in addition to sulphuric acid and tartaric acid, any other components or combinations of components which are compatible with those substances.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Cleaning And De-Greasing Of Metallic Materials By Chemical Methods (AREA)
- Catalysts (AREA)
- Exhaust Gas Treatment By Means Of Catalyst (AREA)
Abstract
The process for anodizing a workpiece of aluminum or aluminum alloys provides for the use of the workpiece as the anode of an electrolytic cell in the presence of an aqueous acid solution which contains from 10 to 200 g sulfuric acid and from 5 to 200 g L(+)-tartaric acid.
Description
- The present invention relates to an anodizing process for a workpiece (such as, for example, a part or a component of a system) of aluminium or aluminium alloys, this definition being intended to comprise pure or almost pure aluminium, as well as combinations thereof in all percentages with other elements.
- In greater detail, this process makes use of the above-mentioned workpiece as the anode of an electrolytic cell in the presence of an aqueous acid solution in order to form on the surface of the workpiece a coating of aluminium oxide.
- This coating results in better properties concerning the resistance to corrosion and the adhesion of paints, bonding agents and other organic coatings suitable for improving the appearance or the resistance to corrosion of the finished workpiece.
- Conventionally, this acid solution substantially comprises sulphuric acid at high concentrations or chromic acid, the latter being the compound mainly used in the field of aeronautics.
- The problem addressed by the present invention is to provide an anodizing process having a lesser toxicological impact on the environment in comparison with the known types, avoiding the use of chromic acid whilst nevertheless obtaining anodized workpieces having properties which are at least equivalent to those of workpieces obtained by conventional means.
- This problem is solved according to the invention by an anodizing process of the type indicated in the introduction to the present description and characterized in that the aqueous acid solution contains from 10 to 200 g sulphuric acid and from 5 to 200 g L(+)-tartaric acid per liter of solution.
- The process according to the invention has the advantage of eliminating, or in any case greatly reducing, the production of industrial waste, in particular waste containing compounds of chromium, without causing the formation of other waste materials having particular toxic or dangerous properties.
- The process according to the invention further has the advantage of having a cycle time which is approximately 40% short of that of the analogous process which makes use of chromic acid, producing anodized workpieces having properties at least equivalent if not superior. Consequently, the process according to the invention allows a considerable reduction in running costs to be obtained in that it results in lower costs for the treatment of the waste and involves a substantially lower rate of consumption for the different chemicals used for replenishing the baths, which have an operational life greater than those used in known processes.
- The aqueous acid solution of the process according to the invention preferably contains from 20 to 80 g sulphuric acid and from 30 to 120 g L(+)-tartaric acid per liter of solution.
- Again preferably, the aqueous solution is maintained, during the anodizing treatment, at a temperature of between ambient temperature and 120° C. and, more preferably, between 25 and 35° C.
- The electrolytic cell, in which the process according to the invention is carried out, is preferably subjected to a voltage of between 1 and 120 V and, more preferably, of between 10 and 30 V.
- The process according to the invention advantageously has a duration of between 5 and 120 minutes and, preferably, of between 5 and 30 minutes.
- The anodizing process is generally preceded by a cleaning and/or deoxidizing treatment of the workpiece to be anodized and can be followed by a sealing treatment and, optionally, rinsing for the anodized workpiece. In principle, these treatments are of conventional type and completely compatible with the present invention and can be selected at will from treatments known to this end by the person skilled in the art.
- The workpiece advantageously has, upon completion of the anodizing treatment, an oxidized surface coating having a thickness of between a few micrometers and several tens of micrometers.
- There now follow, merely by way of non-limiting, illustrative example, examples of the anodizing process according to the invention, as well as a comparative example performed by conventional techniques.
- Anodizing a 2000-Series Aluminium Alloy with Sulphuric-Tartaric Acid
- A workpiece (of a 2000-series aluminium alloy having dimensions of 150×100×1 mm) was first subjected in a conventional manner to cleaning and deoxidizing treatments, such as de- greasing by immersion for approximately 10 minutes, rinsing by immersion in drinking water for approximately 3 minutes, pickling/deoxidation by immersion for approximately 10 minutes and rinsing by immersion in drinking water, preferably followed by further rinsing by immersion in deionized water for a total of approximately 3 minutes.
- The workpiece was then used as the anode of an electrochemical cell, in which the cathode was constituted by corrosion-resistant steel of the type AISI 321 and having a surface area equal to or greater than that to be oxidized and in the presence of an aqueous acid solution containing 45 g sulphuric acid and 80 g L(+)-tartaric acid per liter of solution and was maintained at a temperature of between 30 and 35° C. The workpiece was kept completely immersed in the acid solution.
- The electrical voltage was increased from an initial value of 0 V to a value of 18 V at a rate in the order of 3.6 V/min. The final voltage value was maintained for 25 minutes, producing on the workpiece, upon completion of the anodizing treatment, an oxidized coating having a thickness of approximately 5 μm.
- The anodized workpiece was then subjected to treatments which are conventional per se, such as rinsing with drinking water, preferably followed by further rinsing with deionized water for an overall immersion time of approximately 3 minutes and sealing by immersion for approximately 45 minutes. The workpiece was then dried with air, in particular at a low temperature, if good properties of adhesiveness were required for the oxide.
- The properties of this oxide are indicated in Table I.
- A workpiece (of a 7000-series aluminium alloy having dimensions of 150×100×1 mm) was first subjected in a conventional manner to cleaning and deoxidizing treatments, similar to those described with reference to Example 1.
- The workpiece was then used as the anode of an electrochemical cell, in which the cathode was constituted by corrosion-resistant steel of the type AISI 321 and having a surface area equal to or greater than that to be oxidized and in the presence of an aqueous acid solution containing 45 g sulphuric acid and 80 g L(+)-tartaric acid per liter of solution and was maintained at a temperature of between 30 and 35° C. The workpiece was kept completely immersed in the acid solution.
- The electrical voltage was increased from an initial value of 0 V to a value of 15 V at a rate in the order of 3 V/min. The final voltage value was maintained for 25 minutes, producing on the workpiece, upon completion of the anodizing treatment, an oxidized coating having a thickness of approximately 5 μm.
- The anodized workpiece was then subjected to rinsing and sealing treatments, which are conventional per se, similar to those described with reference to Example 1.
- The properties of the oxide coating obtained are indicated in Table I.
- A workpiece (of a plated aluminium alloy or pure aluminium having dimensions of 150×100×1 mm) was first subjected, in a conventional manner, to cleaning and deoxidizing treatments, similar to those described with reference to Example 1.
- The workpiece was then used as the anode of an electrochemical cell, in which the cathode was constituted by corrosion-resistant steel of the type AISI 321 and having a surface area equal to or greater than that to be oxidized and in the presence of an aqueous acid solution containing 45 g sulphuric acid and 80 g L(+)-tartaric acid per liter of solution and was maintained at a temperature of between 30 and 35° C. The workpiece was kept completely immersed in the acid solution.
- The electrical voltage was increased from an initial value of 0 V to a value of 15 V at a rate in the order of 3 V/min. The final voltage value was maintained for 25 minutes, producing on the workpiece, upon completion of the anodizing treatment, an oxidized coating having a thickness of approximately 5 μm.
- The anodized workpiece was then subjected to rinsing and sealing treatments, which are conventional per se, similar to those described with reference to Example 1.
- The properties of the oxide coating obtained are indicated in Table I.
- A workpiece (of a plated aluminium alloy or a pure aluminium having dimensions of 150×100×1 mm) was first subjected in a conventional manner to cleaning and deoxidizing treatments, similar to those described with reference to Example 1.
- The workpiece was then used as the anode of an electrochemical cell, in which the cathode was constituted by corrosion-resistant steel of the type AISI 321 and having a surface area equal to or greater than that to be oxidized and in the presence of an aqueous acid solution containing 65 g chromic acid and was maintained at a temperature of between 35 and 40° C. The workpiece was kept completely immersed in the acid solution.
- The electrical voltage was increased from an initial value of 0 V to a value of 40 V at a rate in the order of 5 V/min. The final voltage value was maintained for 45 minutes, producing on the workpiece, upon completion of the anodizing treatment, an oxidized coating having a thickness of approximately 3 μm.
- The anodized workpiece was then subjected to rinsing and sealing treatments, which are conventional per se, similar to those described with reference to Example 1.
- The properties of the oxide coating obtained are indicated in Table I.
TABLE I Prior art Chromic acid Prior art INVENTION Property Test method (Example 4) Sulphuric acid (Examples 1, 2, 3) Weight of oxide ASTM B 137 >32 mg/dm2 >32 mg/dm2 >40 mg/dm2 Corrosion resistance Tests in saline mist ac- No corrosion points after No corrosion points after No corrosion points after cording to Iso 7253 exposure for 500 hours exposure for 500 hours exposure for 750 hours Impact test according to No detachment of paint or ASTM D 2794 only slight cracking of paint NOT APPLICABLE No detachment of paint Paint adhesion Adhesion without condi- tioning according to ISO 100% adhesion 90% adhesion 100% adhesion 2409 Adhesion after condition- ing in water for 14 days 100% adhesion 80% adhesion 100% adhesion according to ISO 2409 Influence of oxide on Fatigue tests on cylindrical Reduction in fatigue cycles Reduction in fatigue cy- fatigue life of base test pieces at frequency of not greater than 25% Unsatisfactory cles not greater than 15% metal 10-140 Hz, ratio R:0.1 - A comparison of the results of the tests carried out on the workpieces of the Examples according to the invention and the Example for comparative purposes establishes that the process according to the invention produces oxides having properties which are superior to those of the oxides obtained with conventional processes. Furthermore, the process according to the invention offers environmental advantages associated with the different types of product used, and has a duration which is substantially shorter.
- Of course, without altering the principle of the invention, the details of implementation and the embodiments can vary extensively in relation to the description, which is given purely by way of example, without in any way departing from the scope thereof. In particular, the aqueous acid solution could contain, in addition to sulphuric acid and tartaric acid, any other components or combinations of components which are compatible with those substances.
Claims (7)
1. Process for anodizing a workpiece of aluminium or aluminium alloys, which provides for the use of the workpiece as the anode of an electrolytic cell in the presence of an aqueous acid solution,
wherein the aqueous acid solution contains from 10 to 200 g sulphuric acid and from 5 to 200 g L(+)-tartaric acid.
2. Process according to claim 1 , wherein the aqueous acid solution contains from 20 to 80 g sulphuric acid and from 30 to 120 g L(+)-tartaric acid per liter of solution.
3. Process according to either of the preceding claims, wherein the solution is maintained, during the anodizing treatment, at a temperature of between ambient temperature and 120° C., and preferably between 25 and 35° C.
4. Process according to claim 1 , wherein the electrolytic cell is subjected to a voltage of between 1 and 120 V, and preferably of between 10 and 30 V.
5. Process according to claim 1 , wherein it has a duration of between 5 and 120 minutes, and preferably of between 5 and 30 minutes.
6. Process according to claim 1 , wherein it is preceded by a cleaning, deoxidizing and rinsing treatment for the workpiece to be anodized.
7. Process according to claim 1 , wherein it is followed by a rinsing and sealing treatment for the anodized workpiece.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| ITTO2001A000149 | 2001-02-20 | ||
| IT2001TO000149A ITTO20010149A1 (en) | 2001-02-20 | 2001-02-20 | LOW ECOLOGICAL ANODIZATION PROCEDURE OF A PIECE OF ALUMINUM OR ALUMINUM ALLOYS. |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US20020157961A1 true US20020157961A1 (en) | 2002-10-31 |
Family
ID=11458586
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US10/078,693 Abandoned US20020157961A1 (en) | 2001-02-20 | 2002-02-19 | Anodizing process, with low environmental impact, for a woodpiece of aluminum or aluminum alloys |
Country Status (3)
| Country | Link |
|---|---|
| US (1) | US20020157961A1 (en) |
| EP (1) | EP1233084A3 (en) |
| IT (1) | ITTO20010149A1 (en) |
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20040050709A1 (en) * | 2002-09-17 | 2004-03-18 | The Boeing Company | Accelerated sulfuric acid and boric sulfuric acid anodize process |
| US20070092739A1 (en) * | 2005-10-25 | 2007-04-26 | Steele Leslie S | Treated Aluminum article and method for making same |
| US20070267299A1 (en) * | 2003-01-30 | 2007-11-22 | Yoshiyuki Mitani | Method for Forming Anodic Oxide Layer on Surface of Aluminum or Aluminum Alloy |
| US20090107848A1 (en) * | 2007-10-29 | 2009-04-30 | Pilar Ocon Esteban | Procedure for anodising aluminium or aluminium alloys |
| US20110120873A1 (en) * | 2008-02-08 | 2011-05-26 | Airbus Operations Gmbh | Multifunctional coating of aluminium pieces |
| US20140008236A1 (en) * | 2012-07-04 | 2014-01-09 | Universite De Lorraine | Anodization treatment method for aluminum alloys containing cooper |
| US20160102417A1 (en) * | 2014-10-13 | 2016-04-14 | United Technologies Corporation | Hierarchically structured duplex anodized aluminum alloy |
| WO2016116949A1 (en) | 2015-01-19 | 2016-07-28 | Council Of Scientific & Industrial Research | A process for the preparation of corrosion resistant sealed anodized coatings on aluminum alloy |
| CN110735169A (en) * | 2018-07-18 | 2020-01-31 | 列奥纳多股份公司 | Anodizing method for corrosion protection of aluminum or aluminum alloy elements used in aircraft structures |
| CN119800467A (en) * | 2025-03-13 | 2025-04-11 | 安徽木易科技有限公司 | Method and device for multicolor micro-arc oxidation of alloy surface |
| US12385155B2 (en) | 2022-04-29 | 2025-08-12 | Airbus Operations Gmbh | Methods for anodizing a part surface and subsequently coating the anodized part surface for corrosion protection purposes |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2838754B1 (en) * | 2002-04-22 | 2005-03-18 | Messier Bugatti | METHOD FOR ANODIZING AN ALUMINUM ALLOY PIECE |
| DE10361888B3 (en) * | 2003-12-23 | 2005-09-22 | Airbus Deutschland Gmbh | Anodizing process for aluminum materials |
| DE102004021926A1 (en) | 2004-05-04 | 2005-12-01 | Mtu Aero Engines Gmbh | A method of making a coating and anode for use in such a method |
| CN111112943B (en) * | 2018-10-31 | 2022-04-15 | 江苏瑞尔隆鼎实业有限公司 | Method for machining ABS/ESC valve body for automobile braking system |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| 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 |
| US4430168A (en) * | 1980-04-22 | 1984-02-07 | Empresa Nacional Del Aluminio, S.A. | Process for electrolytically coloring aluminium and the alloys thereof |
| US4806211A (en) * | 1986-05-14 | 1989-02-21 | Swiss Aluminum Ltd. | Aluminum alloy product with uniformly grey, light-fast surface and process for its manufacture |
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| US3382160A (en) * | 1960-03-31 | 1968-05-07 | Asada Tahei | Process for inorganically coloring aluminum |
| CH447758A (en) * | 1965-09-30 | 1967-11-30 | Alusuisse | Process and device for anodic oxidation of aluminum and its alloys |
| DE3265804D1 (en) * | 1981-05-19 | 1985-10-03 | Sankyo Alu Ind | Method of treating a surface of an aluminum to form a pattern thereon |
| CN1004887B (en) * | 1985-12-16 | 1989-07-26 | 青海省太阳能研究所 | Normal temperature fast anode oxidation method for aluminum-plated film |
| CN1106865A (en) * | 1994-02-04 | 1995-08-16 | 大连星光电磁铁厂 | Aluminium foil anodic oxidation electrolyte solution for electric appliance |
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2001
- 2001-02-20 IT IT2001TO000149A patent/ITTO20010149A1/en unknown
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- 2002-02-15 EP EP02003522A patent/EP1233084A3/en not_active Withdrawn
- 2002-02-19 US US10/078,693 patent/US20020157961A1/en not_active Abandoned
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| 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 |
| US4430168A (en) * | 1980-04-22 | 1984-02-07 | Empresa Nacional Del Aluminio, S.A. | Process for electrolytically coloring aluminium and the alloys thereof |
| US4806211A (en) * | 1986-05-14 | 1989-02-21 | Swiss Aluminum Ltd. | Aluminum alloy product with uniformly grey, light-fast surface and process for its manufacture |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20040050709A1 (en) * | 2002-09-17 | 2004-03-18 | The Boeing Company | Accelerated sulfuric acid and boric sulfuric acid anodize process |
| US20070267299A1 (en) * | 2003-01-30 | 2007-11-22 | Yoshiyuki Mitani | Method for Forming Anodic Oxide Layer on Surface of Aluminum or Aluminum Alloy |
| US20070092739A1 (en) * | 2005-10-25 | 2007-04-26 | Steele Leslie S | Treated Aluminum article and method for making same |
| US7527872B2 (en) | 2005-10-25 | 2009-05-05 | Goodrich Corporation | Treated aluminum article and method for making same |
| US20090107848A1 (en) * | 2007-10-29 | 2009-04-30 | Pilar Ocon Esteban | Procedure for anodising aluminium or aluminium alloys |
| EP2055810A2 (en) * | 2007-10-29 | 2009-05-06 | Airbus Espana, S.L. | Procedure for anodising aluminium or aluminium alloys |
| US9334577B2 (en) * | 2008-02-08 | 2016-05-10 | Airbus Operations Gmbh | Multifunctional coating of aluminium pieces |
| US20110120873A1 (en) * | 2008-02-08 | 2011-05-26 | Airbus Operations Gmbh | Multifunctional coating of aluminium pieces |
| US20140008236A1 (en) * | 2012-07-04 | 2014-01-09 | Universite De Lorraine | Anodization treatment method for aluminum alloys containing cooper |
| US20160102417A1 (en) * | 2014-10-13 | 2016-04-14 | United Technologies Corporation | Hierarchically structured duplex anodized aluminum alloy |
| US10094037B2 (en) * | 2014-10-13 | 2018-10-09 | United Technologies Corporation | Hierarchically structured duplex anodized aluminum alloy |
| US10793966B2 (en) | 2014-10-13 | 2020-10-06 | Raytheon Technologies Corporation | Hierarchically structured duplex anodized aluminum alloy |
| US11299815B2 (en) | 2014-10-13 | 2022-04-12 | Raytheon Technologies Corporation | Hierarchically structured duplex anodized aluminum alloy |
| WO2016116949A1 (en) | 2015-01-19 | 2016-07-28 | Council Of Scientific & Industrial Research | A process for the preparation of corrosion resistant sealed anodized coatings on aluminum alloy |
| US10920332B2 (en) * | 2015-01-19 | 2021-02-16 | Council Of Scientific And Industrial Research | Process for the preparation of corrosion resistance sealed anodized coatings on aluminum alloy |
| CN110735169A (en) * | 2018-07-18 | 2020-01-31 | 列奥纳多股份公司 | Anodizing method for corrosion protection of aluminum or aluminum alloy elements used in aircraft structures |
| US12385155B2 (en) | 2022-04-29 | 2025-08-12 | Airbus Operations Gmbh | Methods for anodizing a part surface and subsequently coating the anodized part surface for corrosion protection purposes |
| CN119800467A (en) * | 2025-03-13 | 2025-04-11 | 安徽木易科技有限公司 | Method and device for multicolor micro-arc oxidation of alloy surface |
Also Published As
| Publication number | Publication date |
|---|---|
| EP1233084A2 (en) | 2002-08-21 |
| EP1233084A3 (en) | 2004-03-31 |
| ITTO20010149A1 (en) | 2002-08-20 |
| ITTO20010149A0 (en) | 2001-02-20 |
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