EP4361320A1 - Electrochemical substitution under vacuum of oxide layers on light metals - Google Patents
Electrochemical substitution under vacuum of oxide layers on light metals Download PDFInfo
- Publication number
- EP4361320A1 EP4361320A1 EP23196066.7A EP23196066A EP4361320A1 EP 4361320 A1 EP4361320 A1 EP 4361320A1 EP 23196066 A EP23196066 A EP 23196066A EP 4361320 A1 EP4361320 A1 EP 4361320A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- workpiece
- sealing
- pores
- treatment according
- voltage
- 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.)
- Pending
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- 229910052751 metal Inorganic materials 0.000 title claims abstract description 17
- 239000002184 metal Substances 0.000 title claims abstract description 17
- 150000002739 metals Chemical class 0.000 title description 3
- 238000006467 substitution reaction Methods 0.000 title 1
- 239000011148 porous material Substances 0.000 claims abstract description 55
- 238000007789 sealing Methods 0.000 claims abstract description 46
- 239000000126 substance Substances 0.000 claims abstract description 30
- 239000007789 gas Substances 0.000 claims abstract description 12
- 239000007864 aqueous solution Substances 0.000 claims abstract description 7
- 238000010669 acid-base reaction Methods 0.000 claims abstract description 5
- 239000007788 liquid Substances 0.000 claims abstract description 5
- 239000012535 impurity Substances 0.000 claims abstract description 3
- 125000000524 functional group Chemical group 0.000 claims description 3
- LSNNMFCWUKXFEE-UHFFFAOYSA-M Bisulfite Chemical class OS([O-])=O LSNNMFCWUKXFEE-UHFFFAOYSA-M 0.000 claims description 2
- 150000001242 acetic acid derivatives Chemical class 0.000 claims description 2
- 150000001252 acrylic acid derivatives Chemical class 0.000 claims description 2
- 150000004645 aluminates Chemical class 0.000 claims description 2
- 229910001410 inorganic ion Inorganic materials 0.000 claims description 2
- 239000012948 isocyanate Substances 0.000 claims description 2
- 150000002513 isocyanates Chemical class 0.000 claims description 2
- 150000002891 organic anions Chemical class 0.000 claims description 2
- 150000004760 silicates Chemical class 0.000 claims description 2
- 125000003178 carboxy group Chemical class [H]OC(*)=O 0.000 claims 1
- 150000003440 styrenes Chemical class 0.000 claims 1
- 239000000178 monomer Substances 0.000 description 21
- 238000000034 method Methods 0.000 description 17
- 239000000243 solution Substances 0.000 description 12
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 12
- 239000003566 sealing material Substances 0.000 description 9
- 238000001556 precipitation Methods 0.000 description 8
- 238000006116 polymerization reaction Methods 0.000 description 6
- 238000000576 coating method Methods 0.000 description 5
- 239000000956 alloy Substances 0.000 description 4
- 229910045601 alloy Inorganic materials 0.000 description 4
- 238000002048 anodisation reaction Methods 0.000 description 4
- 238000007743 anodising Methods 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 4
- 239000011248 coating agent Substances 0.000 description 4
- 238000005868 electrolysis reaction Methods 0.000 description 4
- 150000003839 salts Chemical class 0.000 description 4
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 3
- 238000004220 aggregation Methods 0.000 description 3
- 230000002776 aggregation Effects 0.000 description 3
- 239000001257 hydrogen Substances 0.000 description 3
- 229910052739 hydrogen Inorganic materials 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- 238000007745 plasma electrolytic oxidation reaction Methods 0.000 description 3
- 229920000642 polymer Polymers 0.000 description 3
- NIXOWILDQLNWCW-UHFFFAOYSA-M Acrylate Chemical compound [O-]C(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-M 0.000 description 2
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- 229910052782 aluminium Inorganic materials 0.000 description 2
- 150000001450 anions Chemical class 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 239000000919 ceramic Substances 0.000 description 2
- 239000008367 deionised water Substances 0.000 description 2
- 229910021641 deionized water Inorganic materials 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000005530 etching Methods 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 239000001307 helium Substances 0.000 description 2
- 229910052734 helium Inorganic materials 0.000 description 2
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 239000002244 precipitate Substances 0.000 description 2
- 230000005588 protonation Effects 0.000 description 2
- 239000000376 reactant Substances 0.000 description 2
- 238000003860 storage Methods 0.000 description 2
- 230000032258 transport Effects 0.000 description 2
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 1
- 206010020751 Hypersensitivity Diseases 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 150000001298 alcohols Chemical class 0.000 description 1
- 230000007815 allergy Effects 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- WPKYZIPODULRBM-UHFFFAOYSA-N azane;prop-2-enoic acid Chemical compound N.OC(=O)C=C WPKYZIPODULRBM-UHFFFAOYSA-N 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 150000001642 boronic acid derivatives Chemical class 0.000 description 1
- 230000000711 cancerogenic effect Effects 0.000 description 1
- 150000007942 carboxylates Chemical class 0.000 description 1
- 231100000315 carcinogenic Toxicity 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 238000005524 ceramic coating Methods 0.000 description 1
- 239000000460 chlorine Substances 0.000 description 1
- 229910052801 chlorine Inorganic materials 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 239000000356 contaminant Substances 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 230000005684 electric field Effects 0.000 description 1
- 239000003792 electrolyte Substances 0.000 description 1
- 238000001962 electrophoresis Methods 0.000 description 1
- 239000012467 final product Substances 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 229910001385 heavy metal Inorganic materials 0.000 description 1
- 150000002431 hydrogen Chemical class 0.000 description 1
- -1 hydroxide ions Chemical class 0.000 description 1
- 238000010348 incorporation Methods 0.000 description 1
- 230000000977 initiatory effect Effects 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 239000000615 nonconductor Substances 0.000 description 1
- 150000002902 organometallic compounds Chemical class 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 239000000565 sealant Substances 0.000 description 1
- 235000011121 sodium hydroxide Nutrition 0.000 description 1
- 239000011343 solid material Substances 0.000 description 1
- 125000003011 styrenyl group Chemical class [H]\C(*)=C(/[H])C1=C([H])C([H])=C([H])C([H])=C1[H] 0.000 description 1
- 150000003871 sulfonates Chemical class 0.000 description 1
- 238000004381 surface treatment Methods 0.000 description 1
- 238000005496 tempering Methods 0.000 description 1
- 150000007944 thiolates Chemical class 0.000 description 1
- FAQYAMRNWDIXMY-UHFFFAOYSA-N trichloroborane Chemical compound ClB(Cl)Cl FAQYAMRNWDIXMY-UHFFFAOYSA-N 0.000 description 1
- 238000009489 vacuum treatment Methods 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
- C25D11/18—After-treatment, e.g. pore-sealing
- C25D11/20—Electrolytic after-treatment
-
- 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
-
- 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
- C25D11/26—Anodisation of refractory metals or alloys based thereon
-
- 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
- C25D11/30—Anodisation of magnesium or alloys based thereon
Definitions
- the present invention relates to a sealing treatment of a porous oxide layer on a light metal workpiece according to claim 1 and a gas-tight light metal workpiece according to claim 8.
- the surface treatment of light metal workpieces is known from the state of the art, in which the surface's resistance is increased by, for example, anodic oxidation or the creation of ceramic phases on the surface of the metal. These surface oxide layers also form a high ohmic resistance in the dry state.
- the oxide layers have pores that are particularly permeable to gases such as hydrogen or helium.
- gases such as hydrogen or helium.
- the pore size is very small and can be closed by so-called hot water sealing in boiled deionized water through the formation of bohemite.
- the chemical structure of the oxide layer is changed in the process.
- hot water sealing is very energy-intensive.
- the pores of the oxide layers produced by anodization are not sealed tightly. This is why they can only be used in vacuum technology under low vacuum conditions.
- JP-H11 274008 A is a process for sealing porous, oxidic structures on a metal surface.
- the workpiece is immersed in a solution under reduced atmospheres at a reactor pressure so that the pores are filled with the solution and the gas contained therein is displaced.
- the solution transports a monomer into the pores, which is then subjected to an electrochemical or chemical-oxidative polymerization reaction in order to fill the pores with the resulting polymer.
- This process is carried out in two stages: vacuum treatment and then polymerization.
- the US 2021/180203 A1 discloses the controlled introduction of a dissolved monomeric organometallic compound into the interior of a pore of an oxide layer by means of electrophoresis or electropermeation. The monomer is then polymerized by heat treatment.
- the present invention has the object of providing a particularly efficient method for sealing porous structures in the oxide layer of metallic workpieces, which selectively fills the interior of the pores in a gas-tight manner, i.e. in particular filling without coating the porous structure on its outer surface or coating it from the outside.
- impurities in particular liquids and/or gases, are removed from the pores of the workpiece under negative pressure.
- any metal or any oxide layer can be used on a metallic workpiece that is capable of forming a stable bond with the metal surface underneath.
- the workpiece is placed in an aqueous solution of a charged, i.e. ionic, monomeric sealing substance.
- the monomer is preferably present as a solution of its salt or acid.
- the solution therefore preferably contains the monomer exclusively in ionic form.
- a voltage is applied to the workpiece, by means of which the sealing substance is displaced/stored in the pores of the workpiece, and the sealing substance in the pores is subjected to an acid-base reaction, whereby the monomer (sealing substance) is precipitated as such, i.e. not by polymerization in the pore.
- the interior of the pore(s) can be filled particularly completely and efficiently with solid material, since even during precipitation of the monomer in the pore, a fluid exchange with the solution surrounding the workpiece can continue. This allows monomer-free solution to escape from the pore and be displaced by monomer-containing solution.
- the applied electric field can be used for this purpose, for example.
- This process increases the total amount of precipitable material that can be conveyed into a single pore.
- the degree/extent of filling the pores is limited to the concentration dependency of the monomer in the solution.
- the charged monomers are particles which are able to form higher-order structures, in particular agglomerates or aggregates, and/or which can represent precipitation products which preferably clump together.
- the monomer itself can also be formed from subunits and/or smaller monomers.
- the monomer can be polymerizable.
- Both the monomer and the polymer can have a fundamentally inorganic and/or organic structure/basic structure.
- the monomers are preferably significantly smaller than the average pore diameter, which is beneficial for the monomers to penetrate into the pores. However, this is regularly the case due to the size ratios of water-soluble substances and pores in oxide layers on light metals.
- Light metals can be in particular: Al, Mg, Ti and their alloys. Basically, any (light) metal/alloy is suitable that forms stable oxide layers and is stable in aqueous solutions, i.e. does not dissolve in water to form hydrogen, for example.
- the acid-base reaction according to the present invention can be provided selectively in the pores. This allows the precipitation of monomer locally in the pore.
- the provision of protons or hydroxide ions can be provided, for example, by electrolysis of water.
- the method according to the invention benefits from the fact that a limited conductivity can be provided within the pores of the oxide layer, outside the oxide layer whose insulating properties come into play.
- the reactions of the sealing substance embedded in the pores of the oxide layer ultimately aim at the precipitation, clumping or other aggregation of the sealing substance in the pores in order to seal them stably and permanently and can be caused by the applied voltage itself or by reactants which can be generated, for example, by the applied voltage.
- the reaction can be brought about, for example, by electrolysis of water, electrolysis of additives such as alcohols.
- negative pressure is a pressure reduced compared to the local atmospheric pressure, which is preferably reduced by 0.1 to 0.7 bar.
- the treatment of the workpiece may include the incorporation of the sealing material and/or the protonation/precipitation/aggregation of the sealing material and/or the subsequent heat treatment of the workpiece with the sealing material incorporated.
- gas residues or reaction gases By applying a negative pressure to the workpiece when it is in the aqueous solution of the sealing substance or is provided with sealing material, gas residues or reaction gases, for example, can be removed and the components of the sealing substance can penetrate into the pores and react/agglomerate/precipitate there in a targeted manner so that the pores are completely sealed and permanently closed.
- the charged monomeric sealing material is preferably a water-soluble anion which precipitates in the pores through protonation and/or aggregation, thereby permanently and completely closing them.
- the anion is preferably particularly hard, meaning it can only be deprotonated under special conditions, which prevents the formation of water-soluble salts of the protonated and/or precipitated and/or aggregated sealing material under normal operating conditions of the workpieces.
- the molecules of the sealing substances have functional groups from the family/group of substances of the organic anions, such as acrylates, acetates, isocyanates, carboxylates, thiolates, sulfonates, and/or from the family/group of substances of the inorganic ions, such as silicates, aluminates or borates.
- the organic anions such as acrylates, acetates, isocyanates, carboxylates, thiolates, sulfonates, and/or from the family/group of substances of the inorganic ions, such as silicates, aluminates or borates.
- the water-soluble sealing substances can contain monomers for polymerization reactions which, for example, carry the functional groups mentioned above in their side chains. This ensures that the ionic particles are reliably transported into the interior of the pores by the voltage applied to the workpiece.
- the ions can then be neutralized/protonated and/or precipitated. This can apply to both the organic and the inorganic representatives of the sealing substances.
- the voltage is gradually increased during the treatment of the workpiece.
- the voltage during the storage or reaction of the sealing substances in the pores is preferably between 50 and 300 V. It is expediently provided that the voltage is applied to the workpiece using a direct current. This can reliably ensure the transport of the described monomers into the interior of the oxide layer pores.
- the workpiece can then be thermally treated.
- the workpiece is preferably heated to temperatures between 100°C and 300°C.
- the oxide layer of a light metal workpiece can be sealed reliably, quickly, permanently and effectively.
- a light metal workpiece which has a defined protective oxide layer on its surface, is treated in a reactor with a voltage of 50 to 150 V applied to the workpiece, a current density of 1-4 A/qdm and 0.3-0.9 bar in an aqueous solution of styrene salt.
- the workpiece is poled as an anode.
- the salt of the sulfonic acid is precipitated as a free, insoluble acid and the pores are closed.
- the component can be heat-treated for 15 to 20 minutes at 150°C - 200°C, which causes the selected sealing material to polymerize in the pores.
- neutralized acrylate e.g. ammonium acrylate
- the sealed workpiece is removed from the treatment reactor, rinsed in deionized water and can be tempered at 190°C for 10 minutes to further improve the tightness. Measurements have shown that a particularly high level of gas tightness was achieved even before tempering.
- the resulting workpiece has excellent corrosion protection and can be used, for example, in etching processes using etching gases that include boron trichloride or chlorine.
- the dielectric strength of a 50 ⁇ m hard anodization layer on an AlMgSi1 alloy, which was sealed according to the method according to the invention, is 3000 V.
- a 50 ⁇ m thick hard anodization layer on the same material, which was sealed in hot water, only has a dielectric strength of 1000 V in the dry state.
- a 50 ⁇ m thick hard anodizing layer sealed according to the present invention has a high alkaline resistance. Amperometric measurements show that the hard anodizing layer in 10% caustic soda solution only shows a current flow after 48 hours, while the 50 ⁇ m thick hard anodizing layer sealed in hot water only withstands a current breakdown for 2 hours.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Other Surface Treatments For Metallic Materials (AREA)
Abstract
Dichtungsbehandlung einer porösen Oxidschicht auf einem Leichtmetallwerkstück, bei welchem im Unterdruck Verunreinigungen, insbesondere Flüssigkeiten und/oder Gase, aus den Poren des Werkstücks entfernt werden, das Werkstück in eine wässrige Lösung einer geladenen, monomeren Dichtungssubstanz eingebracht wird, an das Werkstück eine Spannung angelegt wird, mittels welcher die Dichtungssubstanz in die Poren des Werkstücks verlagert wird und die Dichtungssubstanz in den Poren elektrochemisch einer Säure-Base-Reaktion unterzogen wird.Sealing treatment of a porous oxide layer on a light metal workpiece, in which impurities, in particular liquids and/or gases, are removed from the pores of the workpiece under negative pressure, the workpiece is introduced into an aqueous solution of a charged, monomeric sealing substance, a voltage is applied to the workpiece, by means of which the sealing substance is displaced into the pores of the workpiece and the sealing substance in the pores is electrochemically subjected to an acid-base reaction.
Description
Die vorliegende Erfindung betrifft eine Dichtungsbehandlung einer porösen Oxidschicht auf einem Leichtmetallwerkstück gemäß dem Anspruch 1 sowie ein gasdichtes Leichtmetallwerkstück gemäß dem Anspruch 8.The present invention relates to a sealing treatment of a porous oxide layer on a light metal workpiece according to claim 1 and a gas-tight light metal workpiece according to claim 8.
Aus dem Stand der Technik ist die Oberflächenbehandlung von Leichtmetallwerkstücken bekannt, bei welcher die Oberfläche durch beispielsweise anodische Oxidation oder die Erzeugung von keramischen Phasen auf der Oberfläche des Metalls in ihrer Widerstandsfähigkeit erhöht werden. Diese Oberflächenoxidschichten bilden auch einen hohen Ohmschen Widerstand im trockenen Zustand.The surface treatment of light metal workpieces is known from the state of the art, in which the surface's resistance is increased by, for example, anodic oxidation or the creation of ceramic phases on the surface of the metal. These surface oxide layers also form a high ohmic resistance in the dry state.
Die Oxidschichten weisen jedoch Poren auf, welche insbesondere für Gase, wie beispielsweise Wasserstoff oder Helium, durchlässig sind. Die Verwendbarkeit solcher Werkstücke im Bereich der Vakuumtechnik, Gasspeicherung oder elektrischer Isolatoren ist daher eingeschränkt.However, the oxide layers have pores that are particularly permeable to gases such as hydrogen or helium. The usability of such workpieces in the field of vacuum technology, gas storage or electrical insulators is therefore limited.
Aus dem Stand der Technik ist es bekannt, auf der Oxidschicht ein Polymer aufzubringen, welches die Poren oberflächlich abdichten soll. Durch den betriebsgemäßen Verschleiß, welchem die Werkstücke, beispielsweise im Bereich der Vakuumpumpen oder Turbomolekularpumpen ausgesetzt sind, wird diese Beschichtung jedoch abgetragen.It is known from the state of the art to apply a polymer to the oxide layer to seal the pores on the surface. However, this coating is removed due to the wear and tear to which the workpieces are exposed during operation, for example in the area of vacuum pumps or turbomolecular pumps.
Bei durch Anodisation hergestellten Oxidschichten, beispielsweise auf Aluminium, ist die Porengröße sehr klein und lässt sich durch das sogenannte Heißwassersealing in gekochtem deionisierten Wasser durch Bildung von Bohemit verschließen. Die chemische Struktur der Oxidschicht wird dabei verändert. Heißwassersealing ist jedoch sehr energieintensiv. Trotz Heißwassersealing werden die Poren der durch Anodisation hergestellten Oxidschichten nicht fest verschlossen. Deshalb sind sie in der Vakuumtechnik nur bei geringem Vakuum einsetzbar.In the case of oxide layers produced by anodization, for example on aluminum, the pore size is very small and can be closed by so-called hot water sealing in boiled deionized water through the formation of bohemite. The chemical structure of the oxide layer is changed in the process. However, hot water sealing is very energy-intensive. Despite hot water sealing, the pores of the oxide layers produced by anodization are not sealed tightly. This is why they can only be used in vacuum technology under low vacuum conditions.
Andere Methoden können Schwermetallsalze als Reaktionspartner mit der Oxidschicht enthalten, welche beispielsweise krebserregend sind oder Allergien am finalen Produkt auslösen können. Aber auch bei dieser Methode erfolgt kein vollständiger Verschluss der Poren.Other methods can contain heavy metal salts as reactants with the oxide layer, which can be carcinogenic or cause allergies to the final product. However, this method does not completely seal the pores either.
Bei der sogenannten Plasmaelektrolytischen Oxidation (PEO) [1-3] lassen sich diese keramischen Schichten aufgrund der Struktur und Zusammensetzung erst gar nicht mit heißem Wasser oder Elektrolyten, wie voranstehend beschrieben, sealen.In the so-called plasma electrolytic oxidation (PEO) [1-3], these ceramic layers cannot be sealed with hot water or electrolytes as described above due to their structure and composition.
Aus der
Mit der Lösung wird ein Monomer in die Poren befördert, welches anschließend einer elektrochemischen oder chemisch-oxidativen Polymerisationsreaktion unterzogen wird, um die Poren mit dem entstehenden Polymer zu füllen. Dieser Prozess wird aber in zwei Stufen durchgeführt also Vakuumbehandlung und dann Polymerisation.The solution transports a monomer into the pores, which is then subjected to an electrochemical or chemical-oxidative polymerization reaction in order to fill the pores with the resulting polymer. This process is carried out in two stages: vacuum treatment and then polymerization.
Die
Diese Verfahren haben jedoch den Nachteil, dass die Polymerisationsreaktion über das Innere der Pore hinaus erfolgt, wodurch das Monomer zum einen über Gebühr verbraucht und auch auf der Oberfläche der Oxidschicht entsteht.However, these processes have the disadvantage that the polymerization reaction takes place beyond the interior of the pore, which causes the monomer to be consumed excessively and also to form on the surface of the oxide layer.
Die vorliegende Erfindung stellt sich die Aufgabe, ein besonders effizientes Verfahren zur Versiegelung von porösen Strukturen in der Oxidschicht metallischer Werkstücke bereitzustellen, welches selektiv das innere der Poren Gasdicht befüllt, also insbesondere ein Befüllen ohne Beschichten die poröse Struktur an seiner äußeren Oberfläche bzw. von außen zu beschichten..The present invention has the object of providing a particularly efficient method for sealing porous structures in the oxide layer of metallic workpieces, which selectively fills the interior of the pores in a gas-tight manner, i.e. in particular filling without coating the porous structure on its outer surface or coating it from the outside.
Die Aufgabe wird durch das erfindungsgemäße Verfahren mit den Merkmalen gemäß Anspruch 1 gelöst.The object is achieved by the method according to the invention with the features according to claim 1.
Man erkennt, dass die Erfindung zumindest durch eine Dichtungsbehandlung einer porösen Oxidschicht auf einem Leichtmetallwerkstück verwirklicht ist, bei welchem das Werkstück, insbesondere in einem Reaktor, in eine wässrige Lösung einer geladenen, monomeren Dichtungssubstanz eingebracht wird,
- im und/oder durch einen Unterdruck Verunreinigungen, insbesondere Flüssigkeiten und/oder Gase, aus den Poren des Werkstücks entfernt werden,
- an das Werkstück eine Spannung angelegt wird, mittels welcher die Dichtungssubstanz in die Poren des Werkstücks verlagert wird
- dadurch gekennzeichnet,
- dass die Dichtungssubstanz in den Poren einer Säure-Base-Reaktion unterzogen und dadurch ausgefällt wird. Bevorzugt werden die Reinigung der Poren und die Ausfällung der Dichtungssubstanz in den Poren als Parallelprozesse also gleichzeitig vorgenommen, wobei ein Initiales anlegen eines Vakuums an das Werkstück zu Beginn der Beschichtung, zumindest kurzfristig, der Ausfällung, insbesondere Auskieselung, und/oder Polymerisierung der Dichtungssubstanz in den Poren vorgeschaltet sein.
- in and/or by means of a negative pressure, contaminants, in particular liquids and/or gases, are removed from the pores of the workpiece,
- a voltage is applied to the workpiece, by means of which the sealing substance is displaced into the pores of the workpiece
- characterized,
- that the sealing substance in the pores is subjected to an acid-base reaction and is thereby precipitated. Preferably, the cleaning of the pores and the precipitation of the sealing substance in the pores are carried out as parallel processes, i.e. simultaneously, whereby an initial application of a vacuum to the workpiece at the start of the coating, at least briefly, precedes the precipitation, in particular silicification, and/or polymerization of the sealing substance in the pores.
Bei der erfindungsgemäßen Dichtungsbehandlung einer porösen Oxidschicht auf einem Leichtmetallwerkstück werden im Unterdruck Verunreinigungen, insbesondere Flüssigkeiten und/oder Gase, aus den Poren des Werkstücks entfernt. Grundsätzlich kann jedes Metall, bzw. jede Oxidschicht auf einem metallischen Werkstück verwendet werden, welches in der Lage ist, einen stabilen Verbund mit der darunter befindlichen Metalloberfläche zu bilden.In the sealing treatment of a porous oxide layer on a light metal workpiece according to the invention, impurities, in particular liquids and/or gases, are removed from the pores of the workpiece under negative pressure. In principle, any metal or any oxide layer can be used on a metallic workpiece that is capable of forming a stable bond with the metal surface underneath.
Das Werkstück wird in eine wässrige Lösung einer geladenen, also ionischen monomeren Dichtungssubstanz, eingebracht. Hierbei liegt das Monomer vorzugsweise als Lösung seines Salzes oder seiner Säure vor. Die Lösung weist daher das Monomer vorzugsweise ausschließlich in Ionischer Form auf. An das Werkstück ist/wird eine Spannung angelegt, mittels welcher die Dichtungssubstanz in die Poren des Werkstücks verlagert/eingelagert wird, und die Dichtungssubstanz in den Poren wird einer Säure-Base Reaktion unterzogen, wodurch das Monomer (Dichtungssubstanz) als solches, also nicht durch Polymerisation in der Pore ausgefällt wird.The workpiece is placed in an aqueous solution of a charged, i.e. ionic, monomeric sealing substance. The monomer is preferably present as a solution of its salt or acid. The solution therefore preferably contains the monomer exclusively in ionic form. A voltage is applied to the workpiece, by means of which the sealing substance is displaced/stored in the pores of the workpiece, and the sealing substance in the pores is subjected to an acid-base reaction, whereby the monomer (sealing substance) is precipitated as such, i.e. not by polymerization in the pore.
Nach der Erfindung lässt sich das Innere der Pore(n) besonders vollständig und effizient mit Feststoff befüllen, da selbst während des Ausfällens des Monomers in der Pore weiter ein Flüssigkeitsaustausch mit der das Werkstück umgebenden Lösung ermöglich sein kann. Hierdurch kann Monomer-freie Lösung aus der Pore austreten und durch Monomer-haltige Lösung verdrängt werden. Hierfür kann z.B. das angelegte elektrische Feld verwendet werden.According to the invention, the interior of the pore(s) can be filled particularly completely and efficiently with solid material, since even during precipitation of the monomer in the pore, a fluid exchange with the solution surrounding the workpiece can continue. This allows monomer-free solution to escape from the pore and be displaced by monomer-containing solution. The applied electric field can be used for this purpose, for example.
Dieser Vorgang erhöht die Gesamtmenge an ausfällbarem Material das in eine einzelne Pore förderbar ist. Bei einem Verfahren, welches hingegen zunächst die Pore mit einer Monomer-Lösung befüllt, um diese anschließend, z.B. mittels Hitze oder sonstiger Mittel zu Polymerisieren, ohne das erfindungsgemäß vorgesehene Ausfällen des Monomers, ist hinsichtlich des Grads/Umfangs der Befüllung der Poren auf die Konzentrationsabhängigkeit des Monomers in der Lösung beschränkt.This process increases the total amount of precipitable material that can be conveyed into a single pore. In a process which first fills the pore with a monomer solution and then polymerizes it, e.g. by means of heat or other means, without the precipitation of the monomer as provided for in the invention, the degree/extent of filling the pores is limited to the concentration dependency of the monomer in the solution.
Bevorzugte Ausführungsformen gehen aus den abhängigen Ansprüchen hervor.Preferred embodiments emerge from the dependent claims.
Nach der vorliegenden Erfindung handelt es sich bei den geladenen Monomeren um Teilchen, welche in der Lage sind, übergeordnete Strukturen, insbesondere Agglomerate oder Aggregate, auszubilden und/oder die Fällungsprodukte darstellen können, welche vorzugsweise verklumpen. Dabei kann das Monomer selbst auch aus Untereinheiten und/oder kleineren Monomeren gebildet sein. Grundsätzlich kann das Monomer polymerisierbar sein. Sowohl das Monomer als auch das Polymer können einen grundsätzlich anorganischen und/oder organischen Aufbau/eine Grundstruktur aufweisen. Bevorzugt sind die Monomeren deutlich kleiner als der durchschnittliche Porendurchmesser, was einem Eindringen der Monomeren in die Poren zuträglich ist. Dies ist jedoch aufgrund der Größenverhältnisse von wasserlöslichen Substanzen und Poren in Oxidschichten auf Leichtmetallen regelmäßig gegeben.According to the present invention, the charged monomers are particles which are able to form higher-order structures, in particular agglomerates or aggregates, and/or which can represent precipitation products which preferably clump together. The monomer itself can also be formed from subunits and/or smaller monomers. In principle, the monomer can be polymerizable. Both the monomer and the polymer can have a fundamentally inorganic and/or organic structure/basic structure. The monomers are preferably significantly smaller than the average pore diameter, which is beneficial for the monomers to penetrate into the pores. However, this is regularly the case due to the size ratios of water-soluble substances and pores in oxide layers on light metals.
Leichtmetalle können insbesondere sein: Al, Mg, Ti sowie deren Legierungen. Grundsätzlich ist jedes (Leicht)metall/jede -legierung geeignet, welches/welche stabile Oxidschichten bildet und in wässrigen Lösungen stabil ist, sich also z.B. nicht in Wasser unter Bildung von Wasserstoff auflöst.Light metals can be in particular: Al, Mg, Ti and their alloys. Basically, any (light) metal/alloy is suitable that forms stable oxide layers and is stable in aqueous solutions, i.e. does not dissolve in water to form hydrogen, for example.
Die Säure-Base-Reaktion nach der vorliegenden Erfindung kann erfindungsgemäß selektiv in den Poren bereitgestellt sein. Hierdurch lässt sich das Ausfällen von Monomer lokal in der Pore erzielen. Das Bereitstellen von Protonen oder Hydroxidionen kann beispielsweise durch Elektrolyse von Wasser bereitgestellt werden. Hierbei profitiert das erfindungsgemäße Verfahren, dass innerhalb der Poren der Oxidschicht eine eingeschränkte Leitfähigkeit bereitgestellt werden kann, außerhalb der Oxidschicht deren isolierenden Eigenschaften zum Tragen kommen. Die Reaktionen der in die Poren der Oxidschicht eingelagerten Dichtungssubstanz zielen letztlich auf das Ausfällen, Verklumpen oder sonstige Aggregation der Dichtungssubstanz in den Poren zum stabilen und dauerhaften Verschließen derselbigen ab und können durch die angelegte Spannung selbst oder durch Reaktionspartner verursacht werden, welche beispielsweise durch die angelegte Spannung erzeugt werden können. Die Reaktion kann beispielsweise durch Elektrolyse von Wasser, Elektrolyse von Additiven, wie beispielsweise Alkoholen, herbeigeführt werden.The acid-base reaction according to the present invention can be provided selectively in the pores. This allows the precipitation of monomer locally in the pore. The provision of protons or hydroxide ions can be provided, for example, by electrolysis of water. The method according to the invention benefits from the fact that a limited conductivity can be provided within the pores of the oxide layer, outside the oxide layer whose insulating properties come into play. The reactions of the sealing substance embedded in the pores of the oxide layer ultimately aim at the precipitation, clumping or other aggregation of the sealing substance in the pores in order to seal them stably and permanently and can be caused by the applied voltage itself or by reactants which can be generated, for example, by the applied voltage. The reaction can be brought about, for example, by electrolysis of water, electrolysis of additives such as alcohols.
Unterdruck ist erfindungsgemäß ein gegenüber dem lokalen Atmosphärendruck verminderter Druck, welcher vorzugsweise um 0,1 bis 0,7 bar verringert wird.According to the invention, negative pressure is a pressure reduced compared to the local atmospheric pressure, which is preferably reduced by 0.1 to 0.7 bar.
Die Behandlung des Werkstücks kann die Einlagerung des Dichtungsmaterials und/oder die Protonierung/Ausfällung/Aggregation des Dichtungsmaterials und/oder die anschließende Wärmebehandlung des Werkstücks mit eingelagertem Dichtungsmaterial umfassen.The treatment of the workpiece may include the incorporation of the sealing material and/or the protonation/precipitation/aggregation of the sealing material and/or the subsequent heat treatment of the workpiece with the sealing material incorporated.
Durch das Anlegen eines Unterdrucks an das Werkstück, wenn dieses in der wässrigen Lösung der Dichtungssubstanz vorliegt bzw. mit Dichtungsmaterial versehen wird, können beispielsweise Gasrückstände oder Reaktionsgase entfernt werden, und die Bestandteile der Dichtungssubstanz können in die Poren so eindringen und dort gezielt reagieren/agglomerieren/ausfällen, so dass die Poren vollständig dicht und dauerhaft verschlossen sind.By applying a negative pressure to the workpiece when it is in the aqueous solution of the sealing substance or is provided with sealing material, gas residues or reaction gases, for example, can be removed and the components of the sealing substance can penetrate into the pores and react/agglomerate/precipitate there in a targeted manner so that the pores are completely sealed and permanently closed.
Vorzugsweise handelt es sich bei dem geladenen monomeren Dichtungsmaterial um ein wasserlösliches Anion, welches durch Protonierung und/oder Aggregierung in den Poren ausfällt und diese somit dauerhaft und vollständig verschließt. Das Anion ist hierbei vorzugsweise von besonderer Härte, kann also nur unter besonderen Bedingungen deprotoniert werden, wodurch die Bildung von wasserlöslichen Salzen des protonierten und/oder ausgefällten und/oder aggregierten Dichtungsmaterials unter betriebsgemäßen Bedingungen der Werkstücke vermieden wird.The charged monomeric sealing material is preferably a water-soluble anion which precipitates in the pores through protonation and/or aggregation, thereby permanently and completely closing them. The anion is preferably particularly hard, meaning it can only be deprotonated under special conditions, which prevents the formation of water-soluble salts of the protonated and/or precipitated and/or aggregated sealing material under normal operating conditions of the workpieces.
Nach einer bevorzugten Weiterbildung der vorliegenden Erfindung ist es vorgesehen, dass die Moleküle der Dichtungssubstanzen funktionelle Gruppen aus der Familie/Stoffgruppe der organischen Anionen, wie beispielsweise der Akrylate, Acetate, Isocyanate, Carboxylate, Thiolate, Sulfonate, und/oder aus der Familie/Stoffgruppe der anorganischen Ionen, wie beispielsweise Silicate, Aluminate oder Borate, aufweisen.According to a preferred development of the present invention, it is provided that the molecules of the sealing substances have functional groups from the family/group of substances of the organic anions, such as acrylates, acetates, isocyanates, carboxylates, thiolates, sulfonates, and/or from the family/group of substances of the inorganic ions, such as silicates, aluminates or borates.
Grundsätzlich können die wasserlöslichen Dichtungssubstanzen Monomere für Polymerisationsreaktionen umfassen, welche z.B. in ihren Seitenketten, die voranstehend genannten funktionellen Gruppen tragen. Hierdurch ist ein durch die an das Werkstück angelegte Spannung verlässlicher Transport der ionischen Teilchen in das Innere der Poren sichergestellt. Anschließend können die Ionen neutralisiert/protoniert und/oder ausgefällt werden. Dies kann sowohl für die organischen als auch für die anorganischen Vertreter der Dichtungssubstanzen gelten.In principle, the water-soluble sealing substances can contain monomers for polymerization reactions which, for example, carry the functional groups mentioned above in their side chains. This ensures that the ionic particles are reliably transported into the interior of the pores by the voltage applied to the workpiece. The ions can then be neutralized/protonated and/or precipitated. This can apply to both the organic and the inorganic representatives of the sealing substances.
Nach einer zweckmäßigen Weiterbildung der vorliegenden Erfindung ist es vorgesehen, dass die Spannung während der Behandlung des Werkstücks sukzessive erhöht wird. Bevorzugt beträgt die Spannung während der Einlagerung oder der Reaktion der Dichtungssubstanzen in den Poren zwischen 50 und 300 V. Zweckmäßigerweise ist es vorgesehen, dass die Spannung unter Verwendung eines Gleichstroms an das Werkstück angelegt wird. Hierdurch kann in verlässlicher Weise der Transport der beschriebenen Monomere in das Innere der Oxidschicht-Poren sichergestellt werden.According to an expedient development of the present invention, it is provided that the voltage is gradually increased during the treatment of the workpiece. The voltage during the storage or reaction of the sealing substances in the pores is preferably between 50 and 300 V. It is expediently provided that the voltage is applied to the workpiece using a direct current. This can reliably ensure the transport of the described monomers into the interior of the oxide layer pores.
Für eine verlässliche Aushärtung des Dichtungsmaterials in den Poren kann das Werkstück anschließend thermisch behandelt werden. Hierbei wird das Werkstück vorzugsweise auf Temperaturen zwischen 100°C bis 300°C erhitzt.To ensure reliable hardening of the sealing material in the pores, the workpiece can then be thermally treated. The workpiece is preferably heated to temperatures between 100°C and 300°C.
Mit dem voranstehend beschriebenen erfindungsgemäßen Verfahren lässt sich die Oxidschicht eines Leichtmetall Werkstücks in verlässlicher Weise und rasch dauerhaft und wirksam verschließen.With the method according to the invention described above, the oxide layer of a light metal workpiece can be sealed reliably, quickly, permanently and effectively.
Anhand der nachfolgenden Ausführungsbeispiele wird die Erfindung näher beschrieben:The invention is described in more detail using the following embodiments:
Ein Leichtmetallwerkstück, welches auf seiner Oberfläche eine festgelegte schützende Oxidschicht trägt, wird in einem Reaktor bei einer an das Werkstück angelegten Spannung von 50 bis 150 V bei einer Stromdichte von 1-4 A/qdm und bei 0,3-0,9 bar in eine wässrige Lösung von Styrol-Salz behandelt. Das Werkstück ist dabei als Anode gepolt.A light metal workpiece, which has a defined protective oxide layer on its surface, is treated in a reactor with a voltage of 50 to 150 V applied to the workpiece, a current density of 1-4 A/qdm and 0.3-0.9 bar in an aqueous solution of styrene salt. The workpiece is poled as an anode.
Durch die Wasserelektrolyse in den Poren des Werkstücks wird das Salz der Sulfonsäure als freie unlösliche Säure ausgefällt, und die Poren werden verschlossen. Um die Beständigkeit des Dichtungsmaterials noch weiter zu erhöhen, kann das Bauteil für 15 bis 20 Minuten bei 150°C - 200°C wärmebehandelt werden, wodurch eine Polymerisation des ausgewählten Dichtungsmaterials in den Poren erfolgt.Through the electrolysis of water in the pores of the workpiece, the salt of the sulfonic acid is precipitated as a free, insoluble acid and the pores are closed. To further increase the durability of the sealing material, the component can be heat-treated for 15 to 20 minutes at 150°C - 200°C, which causes the selected sealing material to polymerize in the pores.
Ein mit 40 µm hartanodisiertes Werkstück aus der Legierung AlSi1MgMn, das in den Behandlungszelle als Anode gepolt ist, wird in der Behandlungszelle unter Vakuum von 0,9 bar bei 100 V und 5 A/qdm 30 Sekunden in einer wässrigen Seallösung aus 100 g/Liter neutralisiertem Acrylat (z.B. Ammoniumacrylat) bei 25°C behandelt. Das negativ geladene Acrylat wandert, während die Spannung angelegt ist, in die Poren des als Anode gepolten Werkstücks.A workpiece made of the alloy AlSi1MgMn, hard-anodized to 40 µm and poled as an anode in the treatment cell, is treated in the treatment cell under a vacuum of 0.9 bar at 100 V and 5 A/qdm for 30 seconds in an aqueous sealing solution of 100 g/liter of neutralized acrylate (e.g. ammonium acrylate) at 25°C. The negatively charged acrylate migrates into the pores of the workpiece poled as an anode while the voltage is applied.
Nach Beenden des Sealprozesses wird das so versiegelte Werkstück der Behandlungsreaktor entnommen, in deionisiertem Wasser gespült und kann zur weiteren Verbesserung der Dichtigkeit 10 Minuten bei 190°C getempert werden. Messungen ergaben, dass eine besonders hohe Gasdichtigkeit, bereits vor dem Tempern erreicht wurde.After the sealing process has been completed, the sealed workpiece is removed from the treatment reactor, rinsed in deionized water and can be tempered at 190°C for 10 minutes to further improve the tightness. Measurements have shown that a particularly high level of gas tightness was achieved even before tempering.
Das resultierende Werkstück weist einen exzellenten Korrosionsschutz auf und kann beispielsweise in Ätzen, deren Ätzgase, die unter anderem Bortrichlorid oder Chlor sind, eingesetzt werden.The resulting workpiece has excellent corrosion protection and can be used, for example, in etching processes using etching gases that include boron trichloride or chlorine.
Messungen im Vakuum zeigen, dass enorm hohe Vakua erreicht werden können und diese über einen langen Zeitraum hinweg stabil vorliegen. Dies lässt sich mit der Dichtheit des Dichtungsmittels in den Poren der Oxidschicht begründen, weil durch die Oxidschicht keine Gase tunneln können. Das gleiche trifft für Bauteile zu, welche unter hohem Druck mit Wasserstoff oder Helium befüllt sind.Measurements in a vacuum show that extremely high vacuums can be achieved and that these remain stable over a long period of time. This can be explained by the tightness of the sealant in the pores of the oxide layer, because no gases can tunnel through the oxide layer. The same applies to components that are filled with hydrogen or helium under high pressure.
Die elektrische Durchschlagfestigkeit einer 50 µm Hartanodisationsschicht auf einer Legierung AlMgSi1, welche nach dem erfindungsgemäßen Verfahren versiegelt wurde, beträgt 3000 V. Im Vergleich dazu weist eine 50 µm dicke Hartanodisationsschicht auf dem gleichen Werkstoff, die im Heißwasser gesealt wurde, nur eine elektrische Durchschlagfestigkeit von 1000 V im trockenen Zustand auf.The dielectric strength of a 50 µm hard anodization layer on an AlMgSi1 alloy, which was sealed according to the method according to the invention, is 3000 V. In comparison, a 50 µm thick hard anodization layer on the same material, which was sealed in hot water, only has a dielectric strength of 1000 V in the dry state.
Eine 50 µm dicke Hartanodisationsschicht, welche nach der vorliegenden Erfindung versiegelt wurde, hat eine hohe alkalische Festigkeit. Amperemetrische Messungen zeigen, dass die in 10%iger Natronlauge befindliche Hartanodisationsschicht einen Stromfluss erst nach 48 Stunden aufweist, während die im Heißwasser gesealte 50 µm dicke Hartanodisationsschicht nur 2 Stunden einem Stromdurchbruch standhält.A 50 µm thick hard anodizing layer sealed according to the present invention has a high alkaline resistance. Amperometric measurements show that the hard anodizing layer in 10% caustic soda solution only shows a current flow after 48 hours, while the 50 µm thick hard anodizing layer sealed in hot water only withstands a current breakdown for 2 hours.
-
[1]
G. P. Wirtz "Ceramic Coatings by Anodic Spark Deposition" Materials & Manufactory Processes 6(1), 87-115 (1991 GP Wirtz "Ceramic Coatings by Anodic Spark Deposition" Materials & Manufacturing Processes 6(1), 87-115 (1991 -
[2]
P. Kurze "Micro Arc / Spark Anodizing - Was ist das?" Oberflächen Polysurfaces 6, 19-23, 2003 P. Kurze "Micro Arc / Spark Anodizing - What is it?" Surfaces Polysurfaces 6, 19-23, 2003 -
[3]
F. Simchen et. al. "Introduction to Plasma Electrolytic Oxidation - An Overview of the Process and Applications" Coatings 2020 F. Simchen et al. al. "Introduction to Plasma Electrolytic Oxidation - An Overview of the Process and Applications" Coatings 2020
Claims (9)
dadurch gekennzeichnet,
dass, gleichzeitig während an das Werkstück eine Spannung angelegt ist, an dem Werkstück ein Unterdruck angelegt ist.Sealing treatment according to claim 1,
characterized,
that , at the same time as a voltage is applied to the workpiece, a negative pressure is applied to the workpiece.
dadurch gekennzeichnet,
dass die Moleküle der Dichtungssubstanzen funktionelle Gruppen aus den Familien der organischen Anionen, wie beispielsweise der substituierten Akrylate und/oder substituierten Acetate und/oder substituierten Styrole und/oder substituierten Isocyanate und/oder Carboxyle und/oder Sulfonsäure und/oder aus der Familie der anorganischen Ionen, wie beispielsweise Silicate, Aluminate, aufweisen.Sealing treatment according to claim 1 or 2,
characterized,
that the molecules of the sealing substances have functional groups from the families of organic anions, such as substituted acrylates and/or substituted acetates and/or substituted styrenes and/or substituted isocyanates and/or carboxyls and/or sulfonic acid and/or from the family of inorganic ions, such as silicates, aluminates.
dadurch gekennzeichnet,
dass die Spannung während der Behandlung des Werkstücks sukzessive erhöht wird.Sealing treatment according to one of claims 1 to 3,
characterized,
that the tension is gradually increased during the treatment of the workpiece.
dadurch gekennzeichnet,
dass die Spannung zwischen 50 und 300 V beträgt.Sealing treatment according to one of claims 1 to 4,
characterized,
that the voltage is between 50 and 300 V.
dadurch gekennzeichnet,
dass die Spannung unter Verwendung eines Gleichstroms an das Werkstück angelegt wird.Sealing treatment according to one of claims 1 to 5,
characterized,
that the voltage is applied to the workpiece using a direct current.
dadurch gekennzeichnet,
dass die Dichtungssubstanz während der elektrochemischen Behandlung in den Poren ausgefällt wird.Sealing treatment according to one of claims 1 to 6,
characterized,
that the sealing substance is precipitated in the pores during the electrochemical treatment.
dadurch gekennzeichnet,
dass die Dichtungssubstanz in der Pore polymerisiert wird.Sealing treatment according to one of claims 1 to 7,
characterized,
that the sealing substance is polymerized in the pore.
dadurch gekennzeichnet,
dass das Werkstück nach Abschluss der elektrochemischen Behandlung, vorzugsweise bei 100°C bis 300°C, wärmebehandelt wird.Sealing treatment according to one of claims 1 to 8,
characterized,
that the workpiece is heat treated after completion of the electrochemical treatment, preferably at 100°C to 300°C.
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Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5834558B2 (en) * | 1981-04-15 | 1983-07-27 | 株式会社フジクラ | Treatment method for anodic oxide film |
US4483751A (en) * | 1981-02-02 | 1984-11-20 | Fujikura Cable Works, Ltd. | Process of treating a nodic oxide film, printed wiring board and process of making the same |
JPS63173313A (en) * | 1987-01-13 | 1988-07-16 | 日本カーリット株式会社 | Solid electrolytic capacitor |
JPH11274008A (en) | 1998-03-25 | 1999-10-08 | Matsushita Electric Ind Co Ltd | Electrolytic capacitor and manufacture thereof |
US20210180203A1 (en) | 2019-12-11 | 2021-06-17 | GM Global Technology Operations LLC | Vacuum impregnation of anodic oxidation coating (aoc) treated surfaces on valve metal substrates |
-
2023
- 2023-09-07 EP EP23196066.7A patent/EP4361320A1/en active Pending
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4483751A (en) * | 1981-02-02 | 1984-11-20 | Fujikura Cable Works, Ltd. | Process of treating a nodic oxide film, printed wiring board and process of making the same |
JPS5834558B2 (en) * | 1981-04-15 | 1983-07-27 | 株式会社フジクラ | Treatment method for anodic oxide film |
JPS63173313A (en) * | 1987-01-13 | 1988-07-16 | 日本カーリット株式会社 | Solid electrolytic capacitor |
JPH11274008A (en) | 1998-03-25 | 1999-10-08 | Matsushita Electric Ind Co Ltd | Electrolytic capacitor and manufacture thereof |
US20210180203A1 (en) | 2019-12-11 | 2021-06-17 | GM Global Technology Operations LLC | Vacuum impregnation of anodic oxidation coating (aoc) treated surfaces on valve metal substrates |
Non-Patent Citations (3)
Title |
---|
F. SIMCHEN: "Introduction to Plasma Electrolytic Oxidation - An Overview of the Process and Applications", COATINGS, 2020 |
G. P. WIRTZ: "Ceramic Coatings by Anodic Spark Deposition", MATERIALS & MANUFACTORY PROCESSES, vol. 6, no. 1, 1991, pages 87 - 115, XP000934359 |
P. KURZE: "Micro Arc / Spark Anodizing - Was ist das?", OBERFLÄCHEN POLYSURFACES, vol. 6, 2003, pages 19 - 23 |
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