[go: up one dir, main page]
More Web Proxy on the site http://driver.im/

EP4450682A1 - Verfahren zur reaktiven imprägnierung einer anodischen aluminiumoxidbeschichtung - Google Patents

Verfahren zur reaktiven imprägnierung einer anodischen aluminiumoxidbeschichtung Download PDF

Info

Publication number
EP4450682A1
EP4450682A1 EP23168208.9A EP23168208A EP4450682A1 EP 4450682 A1 EP4450682 A1 EP 4450682A1 EP 23168208 A EP23168208 A EP 23168208A EP 4450682 A1 EP4450682 A1 EP 4450682A1
Authority
EP
European Patent Office
Prior art keywords
nanopores
anodic
coating
anodized
electrolyte
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
Application number
EP23168208.9A
Other languages
English (en)
French (fr)
Inventor
Svajus Joseph Asadauskas
Tadas Matijo ius
Gedvidas Bikulius
Sigitas Jankauskas
Rimantas Ramanauskas
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Valstybinis Moksliniu Tyrimu Institutas Fiziniu ir Technologijos Mokslu Centras
Original Assignee
Valstybinis Moksliniu Tyrimu Institutas Fiziniu ir Technologijos Mokslu Centras
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Valstybinis Moksliniu Tyrimu Institutas Fiziniu ir Technologijos Mokslu Centras filed Critical Valstybinis Moksliniu Tyrimu Institutas Fiziniu ir Technologijos Mokslu Centras
Priority to EP23168208.9A priority Critical patent/EP4450682A1/de
Publication of EP4450682A1 publication Critical patent/EP4450682A1/de
Pending legal-status Critical Current

Links

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
    • C25D11/24—Chemical after-treatment
    • C25D11/246—Chemical after-treatment for sealing layers
    • 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 a method of preparation of wear-resistant anodic coating on aluminum articles, such as bearings, casings, fasteners, frames, rails and similar.
  • anodic coatings contain porous, coarsely crystalline aluminum oxide, which often forms long vertical nanotubes, protruding continuously from the surface to the substrate.
  • anodic coatings might be additionally treated after electrochemical oxidation to impregnate with dyes, then seal the nanopore openings and prevent the absorption of undesired materials from the environment.
  • the anodic coating adheres strongly to the aluminum substrate, thus making the substrate more abrasion-resistant.
  • anodic coatings are not resistant to long-term mechanical stress of varying intensity, which results in premature wear and major damage to the coating.
  • a typical industrial practice involves hard anodizing (Type III) in an electrolyte, based on sulfuric acid, until a relatively thick anodic coating is produced - 10 to 100 ⁇ m or thicker. It is also important to select a suitable alloy, because not every alloy can be successfully anodized. Some of them, like those of 2000 series aluminum alloys have inclusions of various compositions, which respond to electrochemical reactions in a different manner and might severely distort the formation process of anodic coating. Others produce a distinct phase separation between the substrate and anodic coating, which makes the surface prone to cracking and crumbing. Industrially, aluminum alloys of 5000, 6000 and 7000 series are often selected for anodizing.
  • anodic coating is immersed into a hot solution of alkali or some polymers, which leads to hydroxide buildup on the top of the nanopores.
  • sealed hard anodic coating does not always provide sufficient improvement in friction and wear resistance, even at high thickness.
  • the sealing stage might be replaced with the deposition of barrier lubricants on the surface of anodic coating.
  • a polymeric barrier layer is formed by spraying/wiping a dispersion of fluoropolymers onto the anodized part or its portion, which needs resistance against friction and wear. Immersion into a fluoropolymer dispersion is also possible, followed by various procedures to remove excess liquid, such as dripping, shaking, blow-drying, wiping, etc.
  • the anodized parts must be heated to over 310°C.
  • Such heating is needed for the continuous phase of the dispersion to evaporate and for the dispersed particles of fluoropolymer to congeal into a continuous layer.
  • some polymer molecules can penetrate into the nanopores, but such penetration is limited, because their molecular size approaches that of the nanopore diameter.
  • Another complication is the need to process the layer of fluoropolymer thermo-mechanically before it cools down, such as rubbing it with a cloth while hot. This might require many engineering issues to be resolved during the manufacture because manual operations might be difficult to eliminate.
  • US patent No. US4,784,732 discloses a method covering electrochemical parameters for producing anodic coating, followed by the deposition of a barrier lubricant layer on the top.
  • silicones and fluoropolymers can be infused into the nanopores of 1000 series aluminum alloy, anodized in oxalic acid with subsequent etching in phosphoric acid as disclosed in Sakuraba, K. et. al. "Slippery Liquid-Infused Porous Surfaces on Aluminum for Corrosion Protection with Improved Self-Healing Ability" published in ACS Applied Materials & Interfaces, 2021, vol. 13, no. 37, pp. 45089-45096, Edition of American Chemical Society . Chen, L. et. al.
  • the present invention is dedicated to overcoming the above shortcomings and for producing further advantages over prior art.
  • the invention is a method for reactive impregnation of anodic alumina coating for making a low-wear anodized aluminum articles.
  • Embodiments of the invention comprise four essential stages for producing wear-resistant anodic coatings.
  • an aluminum article is anodized in an acidic electrolyte to produce anodic coatings with open nanopores using conventional Type III or similar hard anodizing procedures. These procedures are well known to those skilled in the art.
  • the obtained coating thickness is 5 - 100 ⁇ m and an internal diameter of nanopores is 5 - 50 nm. Alloys, electrolytes, and anodizing conditions (current density, temperatures, durations, etc.) are selected accordingly to achieve the declared characteristics of nanopores and capable to induce chemical reactions of impregnated compounds within the nanopores.
  • the blotting stage is the next step after anodizing when the fresh anodic coating is dried off.
  • Actual blotting or wiping is optional and can be replaced by vibrating, heating, or blowing air. If the anodized surface is flat, like in laboratory specimens, simple blotting against a lint-free cloth is sufficient to achieve the needed extent of drying.
  • the article After the blotting stage the article has to be transferred to the impregnation stage without allowing its surface to dry out completely, i.e., the article is dried off so that it retains at least 10% of water by volume within the nanopores.
  • the residual water along with the electrolyte makes it possible for the impregnated material to undergo hydrolysis and other reactions within the nanopores.
  • the impregnation stage covers the essential process of impregnating an anodized article with a liquid or liquefied material, which penetrates the nanopores of said anodic coating and reacts with the residual electrolyte and water.
  • the impregnating media is liquid, therefore, if any solid compounds are employed, the temperature should be high enough to melt them.
  • the liquid does not have to be fully homogeneous, it can constitute an emulsion or colloidal solution, or even have several liquid phases.
  • Drying stage involves heating and drying the impregnated anodic coating for two purposes: 1) to drive the reaction between the liquid and residual electrolyte within the nanopores and 2) to prevent nanopore sealing. Water evaporates on its own from the impregnated anodic coating.
  • a low-wear coating is prepared in four stages, starting with an aluminum substrate.
  • the substrate, surface for coating can be pure aluminum or its cast, forged, rolled, or wrought alloy.
  • the anodization, surface for coating is prepared, type III Hard anodizing is carried out for the prepared surface and the anodized surface is rinsed with deionized water.
  • the obtained coating thickness is from 5 to 100 ⁇ m and internal diameter of nanopores in the coating is from 5 to 50 nm.
  • the nanopores cannot provide a sufficient reservoir for the reaction with the impregnated material and residual electrolyte. If the anodic coating is thicker than 100 ⁇ m, the brittleness becomes excessive and the nanopores are too deep for the compounds, produced during the reaction to migrate into the friction zone. Nanopores of less than 5 nm might limit the penetration of impregnating compounds and chemical reactions with the residual electrolyte. On the contrary, wide nanopores from 50 nm to several hundred nanometers have insufficient mechanical resistance and load-carrying capacity leading to major surface damage and wear debris formation.
  • the anodized surface is dried off to retain some deionized water within nanopores of obtained anodic coating.
  • the anodic coatings retain at least 10% of original deionized water contents in nanopores before being immersed into impregnating liquid or liquefied material.
  • Actual blotting or wiping is optional and can be replaced by vibrating, heating, or blowing air. If the anodized surface is flat, like in laboratory specimens, simple blotting against a lint-free cloth is sufficient to achieve the needed extent of drying.
  • amphiphilic compounds may contain 50-100% wt. of molecules with one, two or three alkyl chains, whose chain length is from C6 to C24 with or without methyl or ethyl pendants or double bonds. Said molecules have a moiety or several such moieties, capable of oxidizing or hydrolyzing in the presence of residual acid within the nanopores of said anodic coatings.
  • the molecules should also contain a functional group, capable of engaging into oxidation and/or hydrolysis reactions with the residual electrolyte deionized water and electrolyte within the nanopores of obtained anodic coating.
  • the residual water along with the electrolyte makes it possible for the impregnated material to undergo hydrolysis and other reactions within the nanopores.
  • these molecules must have such alkyl chains, which would impart lubricating properties to the compounds, freshly formed by combining with the residual electrolyte within the nanopores.
  • Molecules with phosphite, sulfide and/or ester functional groups and one, two or three alkyl chains assure the most effective interaction with the residual electrolyte and dramatically increase the wear resistance of anodic alumina coatings.
  • the impregnation stage covers the essential process of impregnating the anodized article with a liquid or liquefied material, which penetrates the nanopores of said anodic coating and reacts with the residual electrolyte and water.
  • the impregnating media is liquid, therefore, if any solid compounds are employed, the temperature should be high enough to melt them.
  • the liquid does not have to be fully homogeneous, it can constitute an emulsion or colloidal solution, or even have several liquid phases. Solid particles, even if nanosized, are not likely to contribute to the reactions within nanopores. Most nanoparticles would be too large to migrate into the nanopores, but even if they are smaller than the internal diameter of the nanopore, they would still agglomerate and block the passage into the inner part of the nanopore.
  • nanoparticles in the impregnation solution is beneficial to wear resistance.
  • the nanoparticles can adhere to the surface of anodic coatings and then participate in the subsequent processes in the friction zone. Impregnation of the anodic coatings with nanoparticle dispersions might lead to appreciable wear resistance. The continuous phase of such dispersion can still penetrate the nanopores and induce reactions with the residual electrolyte.
  • the impregnated anodic coating is completely dried to complete the reactions with the residual deionized water and electrolyte.
  • Complete drying the impregnated anodic coating drive reaction between the impregnation material in liquid form and residual electrolyte within the nanopores and to prevent nanopore sealing.
  • the compounds within the open nanopores are free to migrate into the friction zone thus reducing wear of the anodized aluminum surface.
  • the impregnated article is stored under humid conditions, the excessive humidity is likely to result in hydroxide formation on the top of the nanopores.
  • the hydroxides may seal the openings and it will become difficult for the compounds within nanopores to migrate into the friction zone.
  • preparation of an aluminum surface comprises etching the aluminum surface in an alkaline solution for example solution of 30 g/L NaOH + 25 g/L Na 3 PO 4 + 75 g/L Na 2 CO 3 for 45 s at 60 °C. After rinsing in deionized (onwards - DI) water the aluminum surface is cleaned for 1-2 min in 30% HNOs and rinsed in DI water again. Then the surface is fixed, for example into a titanium holder, and immersed into a continuously mixed H 2 SO 4 /oxalic a.
  • an alkaline solution for example solution of 30 g/L NaOH + 25 g/L Na 3 PO 4 + 75 g/L Na 2 CO 3 for 45 s at 60 °C.
  • deionized (onwards - DI) water the aluminum surface is cleaned for 1-2 min in 30% HNOs and rinsed in DI water again. Then the surface is fixed, for example into a titanium holder, and immersed into a continuously mixed H 2 SO 4 /o
  • electrolyte (175 g/L H 2 SO 4 + 30 g/L (COOH) 2 ⁇ 2 H 2 O + 55.5 g/L Al 2 (SO 4 ) 3 ⁇ 18 H 2 O) for 70 min at 2 A/dm 2 anodic current density.
  • current density 1.6 - 2.4 A/dm 2
  • electrolyte temperature 14-16°C
  • duration of 67 to 73 min is retained.
  • the coating is preferably 60 ⁇ 10 ⁇ m thick. The anodized surface is immersed into an ultrasonic bath and sonicated in DI water without heat for rinsing.
  • the anodized surface is soaked off from excess water droplets and dried off to retain some moisture in nanopores before the impregnation stage, i.e., the article is dried off so that it retains at least 10% of water by volume within the nanopores.
  • sheet of aluminum alloy 6082 of 96.72% wt., where contents of the alloy are 1.10 wt.% Si, 1.02 wt.% Mg, 0.61 wt.% Mn, 0.54 wt.% Fe, and sheet of aluminum alloy 7075 of 87.39% wt., where contents of the alloy are 7.74 wt.% Zn, 2.80 wt.% Mg, 2.08 wt.% Cu, with a thickness of 1.5 ⁇ 0.5 mm were used for coating.
  • the aluminum alloy sheets were laser cut to produce 16 ⁇ 1 mm outside diameter (OD) discs from these sheets and subject them to surface preparation and subsequent anodizing.
  • the anodized discs were immersed into 170 W ultrasonic bath, model VTUSC3 Velleman, Belgium, and sonicated at full power for 5 to 10 min in DI water without heat for rinsing.
  • the discs in the blotting stage were placed onto lint-free absorbent paper to soak off the excess water droplets and to dried off to retain some moisture in nanopores before the impregnation stage, i.e. the article is dried off so that it retain at least 10% of water by volume within the nanopores.
  • Employed anodization parameters and established properties of the obtained coatings are listed in Table 1. Table 1.
  • the main anodization parameters i.e., electrolyte composition, processing characteristics, etc., and measured properties of obtained anodic coatings before subsequent impregnation stage of sheet of aluminum alloy 6082 and sheet of aluminum alloy 7075.
  • Anodization parameters Values Anodic coating properties Values Sulfuric acid 175 g/L Nanopore density on 6082 1040 ⁇ 120 pores/ ⁇ m 2 Aluminum sulfate 55 g/L Nanopore density on 7075 1290 ⁇ 100 pores/ ⁇ m 2 Oxalic acid 30 g/L Avg nanopore ID on 6082 20 nm Current density 2 A/cm 2 Avg nanopore ID on 7075 15 nm DC voltage 15 V Roughness, Ra on 6082 1.49 ⁇ 0.14 ⁇ m Temperature 15°C Roughness, Ra on 7075 1.13 ⁇ 0.13 ⁇ m Achieved thickness 60 ⁇ m Hardness on 6082 4.8 ⁇ 0.5 GPa Duration 60 min Hardness on 7075 4.1 ⁇ 0.4 GPa
  • the discs were dried off, i.e. the article is dried off so that it retain at least 10% of water by volume within the nanopores, before immersing them into any of the materials, used for impregnation, except for polytetrafluoroethylene (PTFE).
  • PTFE polytetrafluoroethylene
  • the anodized discs with PTFE layers were used as a control material for assessing the tribological performance of anodic coatings, impregnated in claimed liquids.
  • the fluoropolymer-based DryFilm RA/IPA dispersion from DuPont (USA) was employed. This dispersion is among the state-of-the-art commercial PTFE dispersions, which are frequently used on commercial anodized items to build a top barrier layer of low friction and good resistance to wear.
  • Impregnation with PTFE was based on procedures often employed industrially in anodizing plants, utilizing fully dried anodic coatings. The dispersion contained 25% wt.
  • PTFE particles suspended in isopropanol by auxiliary surfactants (CAS N° 65530-85-0 , 24938-91-8 and 9002-84-0).
  • auxiliary surfactants CAS N° 65530-85-0 , 24938-91-8 and 9002-84-0. The dispersion was agitated well before each use to achieve full homogeneity and applied as is.
  • the discs for impregnating with PTFE were fully dried by storing them in a desiccator for at least one day.
  • the dry anodized discs were immersed for 15 minutes at room temperature into the said PTFE dispersion without agitation, then removed and suspended vertically in the air for 30 min. Afterwards, a thermo-mechanical process was performed to improve the adherence of the polymer to the anodic coating.
  • the discs with dried off i.e. the article is dried off so that it retain at least 10% of water by volume within the nanopores
  • anodic coatings were immersed into a heated liquid or liquefied material.
  • a series of materials were tested as immersion media.
  • Technical grade oleic a. of 70% purity was acquired from StanChem (Poland), dilauryl sulfide of 98% purity, methyl oleate of 90% purity and stearic a.
  • a Micro-PoD TR-20 M63 tribometer (Ducom Instruments Europe B.V., Netherlands) was employed by utilizing a ball-on-disc rotational configuration.
  • two types of 6 mm OD balls were used: 1) bearing steel 100Cr6 (96.5% purity, grade G100, hardness ⁇ 800 HV and roughness Ra 0.100 ⁇ m) and 2) corundum Al 2 O 3 (99.8% purity, grade G16, hardness ⁇ 2900 HV and roughness Ra 0.025 ⁇ m) from RGP International Srl (Italy).
  • the balls were fixed into the holder and pressed under the 50 ⁇ 0.5 N load by a pneumatic piston against the coated specimen, mounted on a rotary part.
  • the rotational motion of 500 rpm was maintained with a 5 ⁇ 0.5 mm radius resulting in a circular track length of 31.4 mm in one revolution, a so-called friction cycle.
  • the average dynamic COF value was calculated automatically as the ratio between friction force and normal load using Winducom 2010 software. The results were presented as COF changes with progressing friction in terms of number of cycles. To ensure good reproducibility, each sample was tested 2 or more times at given conditions and the most representative runs were selected for the comparison between samples.
  • the COF variation throughout the course of the measurement was inspected and the threshold was established by determining the number of friction cycles (i.e. revolutions), after which friction and wear rate began to continuously increase much faster. This threshold coincides with the beginning of severe abrasion; hence it is considered as an abrasion onset.
  • lubricity additives are initially liquid, after such reactions they should form solids or bond to the inner walls of nanopores sufficiently strongly without exiting to the surface under ambient conditions. Therefore, the anodic coating should still be considered as dry coating, despite the impregnation with the aforementioned lubricity additives.
  • Rapeseed oil, trilaurin and dialkyl sebacate were also included as comparative materials to represent esters, which can hydrolyze within nanopores.
  • a fully formulated synthetic engine lubricant 0W-40 in compliance with API SM certification was tested as the comparative material for impregnation.
  • 0W-40 Since the major constituent, over 80% wt., of 0W-40 was a poly alpha olefin basestock, i.e., an alkane, it was not likely to hydrolyze or oxidize to any significant extent. Admittedly, some additives in 0W-40 could react with the residual electrolyte in the nanopores of anodic coating. However, the remaining basestock would be able to resurface and such anodic coating, which was impregnated with unreacted liquid lubricant, could not be considered as a dry surface. After impregnation, a significant portion of 0W-40 lubricant would reside on the top, implying liquid lubrication conditions and rendering the anodic coating visually inferior.
  • Squalane is often employed to simulate paraffinic mineral oil as lubricant basestock, but its performance as an impregnating compound is not as effective on anodized 6082 discs as the PTFE layers.
  • Squalene which has six double bonds, performs nearly as poorly as fully saturated squalane. Their wear resistance clearly exceeds that of PTFE layers only on anodized 7075 discs against corundum. It remains unclear why squalane and squalene become much better under the latter conditions. Since 7075 has 7.74% Zn, additional catalytic effects could take place and induce reactions, which could not take place in 6082 alloys.
  • Typical Anti Wear additives used by lubricant manufacturers, are developed to improve wear resistance under various lubrication regimes. There isn't any dominating compound for reducing wear of alumina. Oleic acid, ZDDP and 2EH-phosphite are widely used to reduce wear of steel. The former two improve wear-resistance of the anodic coatings during the tribotests against steel counter-body but appear to be less effective against the corundum. The performance of the 2EH-phosphite does not appear significantly better than that of PTFE layers.
  • exhibits are only examples and should not be interpreted to restrict the scope of the invention.
  • the information presented comprises particular features in which the exhibits differ, but all exhibits follow method steps for reactive impregnation of anodic alumina coating even though not recited entirely.
  • the discs of 6082 and 7075 alloys were anodized in the electrolyte of sulfuric and oxalic acids, rinsed with water, blotted with a lint-free paper cloth and suspended in the air at room temperature. Within 36 hours after anodization, when the discs retained at least 10% of original water contents, they were immersed into dilauryl succinate at 90°C for 1 hr and suspended in the air at 90°C for 1 hr. After cooling and storing at room temperature for at least 16 hrs, tribotests were performed against corundum balls.
  • the discs of 6082 and 7075 alloys with dilauryl succinate recorded the averages of 3 200 and 6 700 cycles before abrasion, much better than discs with PTFE layers, which recorded 810 and 520 cycles respectively. Tribotests were also performed against steel balls.
  • the discs of 6082 and 7075 alloys with dilauryl succinate recorded the averages of 9 300 and 40 200 cycles before abrasion, whereas those with PTFE layers averaged 250 and 680 respectively.
  • the discs of 6082 and 7075 alloys were anodized in the electrolyte of sulfuric and oxalic acids, rinsed with water, blotted with a lint-free paper cloth and suspended in the air at room temperature. Within 36 hours after anodization, when the discs retained at least 10% of original water contents, they were immersed into trilauryl phosphite at 90°C for 1 hr and suspended in the air at 90°C for 1 hr. After cooling and storing at room temperature for at least 16 hrs, tribotests were performed against corundum balls.
  • the discs of 6082 and 7075 alloys with trilauryl phosphite recorded the averages of 2 400 and 11 500 cycles before abrasion, much better than discs with PTFE layers, which recorded 810 and 520 cycles respectively. Tribotests were also performed against steel balls.
  • the discs of 6082 and 7075 alloys with trilauryl phosphite recorded the averages of 5 150 and 89 800 cycles before abrasion, whereas those with PTFE layers averaged 250 and 680 respectively.
  • the impregnated coatings appeared dry because lauryl and phosphite moieties, which were formed due to the hydrolysis of trilauryl phosphite, were reacted into solid compounds within the nanopores after oxidation and saponification.
  • Impregnation with trilauryl phosphite delivers much more wear resistance compared to tri-isooctyl phosphite.
  • Lauryl chains are much more beneficial to the lubricating properties of the compounds in the friction zone, compared to shorter chains of isooctyl, which also include ethyl pendants.
  • the discs of 6082 and 7075 alloys were anodized in the electrolyte of sulfuric and oxalic acids, rinsed with water, blotted with a lint-free paper cloth and suspended in the air at room temperature. Within 36 hours after anodization, when the discs retained at least 10% of original water contents, they were immersed into methyl oleate at 90°C for 1 hr and suspended in the air at 90°C for 1 hr. After cooling and storing at room temperature for at least 16 hrs, tribotests were performed against corundum balls.
  • the discs of 6082 and 7075 alloys with methyl oleate recorded the averages of 1 000 and 2 100 cycles before abrasion, being better than discs with PTFE layers, which recorded 810 and 520 cycles respectively. Tribotests were also performed against steel balls.
  • the discs of 6082 and 7075 alloys with methyl oleate recorded the averages of 3 400 and 33 200 cycles before abrasion, whereas those with PTFE layers averaged 250 and 680 respectively.
  • the discs of 6082 and 7075 alloys were anodized in the electrolyte of sulfuric and oxalic acids, rinsed with water, blotted with a lint-free paper cloth and suspended in the air at room temperature. Within 36 hours after anodization, when the discs retained at least 10% of original water contents, they were immersed into dilauryl sulfide at 90°C for 1 hr and suspended in the air at 90°C for 1 hr. After cooling and storing at room temperature for at least 16 hrs, tribotests were performed against corundum balls.
  • the disc of 6082 and 7075 alloys with dilauryl sulfide recorded the averages of 590 and 1 500 cycles before abrasion, being comparable or better than discs with PTFE layers, which recorded 810 and 520 cycles respectively. Tribotests were also performed against steel balls.
  • the discs of 6082 and 7075 alloys with dilauryl sulfide recorded the averages of 20 300 and 2 900 cycles before abrasion, whereas those with PTFE layers averaged 250 and 680 respectively.
  • the impregnated coatings appeared dry because lauryl and sulfide moieties, which were formed due to the hydrolysis of dilauryl sulfide, were reacted into solid compounds within the nanopores after oxidation and saponification.
  • the discs of 6082 and 7075 alloys were anodized in the electrolyte of sulfuric and oxalic acids, rinsed with water, blotted with a lint-free paper cloth and suspended in the air at room temperature. Within 36 hours after anodization, when the discs retained at least 10% of original water contents, they were immersed into isolauryl pentasulfide at 90°C for 1 hr and suspended in the air at 90°C for 1 hr. After cooling and storing at room temperature for at least 16 hrs, tribotests were performed against corundum balls.
  • the discs of 6082 and 7075 alloys with trilauryl phosphite recorded the averages of 1 800 and 3 800 cycles before abrasion, much better than discs with PTFE layers, which recorded 810 and 520 cycles respectively. Tribotests were also performed against steel balls.
  • the discs of 6082 and 7075 alloys with isolauryl pentasulfide recorded the averages of 1 000 and 5 200 cycles before abrasion, whereas those with PTFE layers averaged 250 and 680 respectively.
  • the impregnated coatings appeared dry because isolauryl and sulfide moieties, which were formed due to the hydrolysis of isolauryl pentasulfide, were reacted into solid compounds within the nanopores after oxidation and saponification.
  • the discs of 6082 and 7075 alloys were anodized in the electrolyte of sulfuric and oxalic acids, rinsed with water, blotted with a lint-free paper cloth and suspended in the air at room temperature. Within 36 hours after anodization, when the discs retained at least 10% of original water contents, they were immersed into trilaurin at 90°C for 1 hr and suspended in the air at 90°C for 1 hr. After cooling and storing at room temperature for at least 16 hrs, tribotests were performed against corundum balls.
  • the discs of 6082 and 7075 alloys with trilaurin recorded the averages of 4 000 and 6 300 cycles before abrasion, much better than discs with PTFE layers, which recorded 810 and 520 cycles respectively. Tribotests were also performed against steel balls.
  • the discs of 6082 and 7075 alloys with trilaurin recorded the averages of 7 000 and 4 400 cycles before abrasion, whereas those with PTFE layers averaged 250 and 680 respectively.

Landscapes

  • Chemical & Material Sciences (AREA)
  • General Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Lubricants (AREA)
EP23168208.9A 2023-04-17 2023-04-17 Verfahren zur reaktiven imprägnierung einer anodischen aluminiumoxidbeschichtung Pending EP4450682A1 (de)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP23168208.9A EP4450682A1 (de) 2023-04-17 2023-04-17 Verfahren zur reaktiven imprägnierung einer anodischen aluminiumoxidbeschichtung

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP23168208.9A EP4450682A1 (de) 2023-04-17 2023-04-17 Verfahren zur reaktiven imprägnierung einer anodischen aluminiumoxidbeschichtung

Publications (1)

Publication Number Publication Date
EP4450682A1 true EP4450682A1 (de) 2024-10-23

Family

ID=86052402

Family Applications (1)

Application Number Title Priority Date Filing Date
EP23168208.9A Pending EP4450682A1 (de) 2023-04-17 2023-04-17 Verfahren zur reaktiven imprägnierung einer anodischen aluminiumoxidbeschichtung

Country Status (1)

Country Link
EP (1) EP4450682A1 (de)

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB884477A (en) * 1957-12-13 1961-12-13 Reynolds Metals Co Method of coloring metal and article produced thereby
US3567597A (en) 1969-06-11 1971-03-02 Bunker Ramo Method of making a dry lubricant coating
DE2137052A1 (de) * 1971-07-23 1973-04-05 Sigmund Bereday Verfahren zum modifizieren von aluminiumoberflaechen, die modifizierten aluminiumoberflaechen und hiermit versehene aluminiumerzeugnisse, wie schichtstoffe
US4784732A (en) 1986-07-24 1988-11-15 Covino Charles P Electrolytic formation of an aluminum oxide layer
US20030213698A1 (en) 2002-05-09 2003-11-20 Ryosuke Kawagoshi Process for lubrication-treating aluminum or aluminum alloy material
US20050062317A1 (en) 2003-08-04 2005-03-24 Webasto Ag Guide arrangement for displaceable parts of motor vehicle roofs and process for the production thereof
US20050218004A1 (en) 2003-11-26 2005-10-06 Calphalon Corporation Process for making a composite aluminum article
WO2019128210A1 (zh) 2017-12-28 2019-07-04 山东大学 一种提高干摩擦条件下铝合金表面耐磨性的方法
CN113355713A (zh) * 2021-05-14 2021-09-07 张健 一种减摩润滑铝合金

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB884477A (en) * 1957-12-13 1961-12-13 Reynolds Metals Co Method of coloring metal and article produced thereby
US3567597A (en) 1969-06-11 1971-03-02 Bunker Ramo Method of making a dry lubricant coating
DE2137052A1 (de) * 1971-07-23 1973-04-05 Sigmund Bereday Verfahren zum modifizieren von aluminiumoberflaechen, die modifizierten aluminiumoberflaechen und hiermit versehene aluminiumerzeugnisse, wie schichtstoffe
US4784732A (en) 1986-07-24 1988-11-15 Covino Charles P Electrolytic formation of an aluminum oxide layer
US20030213698A1 (en) 2002-05-09 2003-11-20 Ryosuke Kawagoshi Process for lubrication-treating aluminum or aluminum alloy material
US20050062317A1 (en) 2003-08-04 2005-03-24 Webasto Ag Guide arrangement for displaceable parts of motor vehicle roofs and process for the production thereof
US20050218004A1 (en) 2003-11-26 2005-10-06 Calphalon Corporation Process for making a composite aluminum article
WO2019128210A1 (zh) 2017-12-28 2019-07-04 山东大学 一种提高干摩擦条件下铝合金表面耐磨性的方法
CN113355713A (zh) * 2021-05-14 2021-09-07 张健 一种减摩润滑铝合金

Non-Patent Citations (4)

* Cited by examiner, † Cited by third party
Title
CHEN, L: "Tribology International", vol. 122, 2018, ELSEVIER, article "Enhancing tribological performance by anodizing micro-textured surfaces with nano-MoS coatings prepared on aluminum-silicon alloys", pages: 84 - 95
IΛLU, D: "Chemical Engineering Journal", vol. 368, 2019, ELSEVIER, article "Durable lubricant-infused anodic aluminum oxide surfaces with high-aspect-ratio nanochannels", pages: 138 - 147
SAKURABA, K: "ACS Applied Materials & Interfaces", vol. 13, 2021, AMERICAN CHEMICAL SOCIETY, article "Slippery Liquid-Infused Porous Surfaces on Aluminum for Corrosion Protection with Improved Self-Healing Ability", pages: 45089 - 45096
TADAS MATIJOSIUS ET AL: "Determination of the dye penetration rate in porous aluminum oxide using Raman spectroscopy", COLORATION TECHNOLOGY, WILEY, HOBOKEN, USA, vol. 135, no. 4, 8 May 2019 (2019-05-08), pages 275 - 282, XP072248090, ISSN: 1472-3581, DOI: 10.1111/COTE.12404 *

Similar Documents

Publication Publication Date Title
Martini et al. PEO layers obtained from mixed aluminate–phosphate baths on Ti–6Al–4V: Dry sliding behaviour and influence of a PTFE topcoat
US9914152B2 (en) Polytetrafluoroethylene thin film with polydopamine adhesive layer
KR102633391B1 (ko) 나노-첨가제를 이용한 개량 윤활제
CA2968630C (fr) Procede de traitement superficiel d'une piece en acier par nitruration ou nitrocarburation, oxydation puis impregnation
CN108187990A (zh) 含有石墨烯/二硫化钼的钛及钛合金表面自润滑耐磨涂层的制备方法
Lin et al. Fretting wear of micro-arc oxidation coating prepared on Ti6Al4V alloy
CN107281544A (zh) 一种钛及钛合金表面自润滑耐磨复合涂层及其制备方法
EP4450682A1 (de) Verfahren zur reaktiven imprägnierung einer anodischen aluminiumoxidbeschichtung
Sun et al. Superlubricity of Si 3 N 4 sliding against SiO 2 under linear contact conditions in phosphoric acid solutions
CA2721790A1 (en) Methods for enhancing lubricity of surfaces
CN105648499A (zh) 一种钛合金表面梯度减摩耐磨涂层及其制备方法
Wang et al. Fabrication of self-lubricating coating on aluminum and its frictional behaviour
Rigas et al. Tribological Behavior of High-Strength Aluminum Alloys in Combination with Dry Lubricants at High Forming Temperatures
Sivakumaran et al. The wear characteristics of heat treated manganese phosphate coating applied to AlSi D2 steel with oil lubricant
Tahir et al. Influence of humidity on the tribological performance of graphite reinforced aluminium anodic oxide coating
JP2000117888A (ja) 複層摺動部材ならびにその製造方法
Matijošius et al. Effects of electrolyte and Ti layers on static and dynamic friction of anodized alumina
Wu et al. Novel structured anodic oxide films containing surface layers and porous sublayers showing excellent wear resistance performance
Ilaiyavel et al. Investigation of wear coefficient of manganese phosphate coated tool steel
Erdemir et al. Clean and cost-effective dry boundary lubricants for aluminum forming
Hernández-Sánchez et al. Tribological and Mechanical Behavior of Automotive Crankshaft Steel Superficially Modified Using the Boriding Hardening Process
Hanke et al. Wear Behaviour of Nanoporous Alumina Coatings from Anodic Oxidation
Matijošius et al. Antifrictional Effect of Biobased Fillers on Bioceramic Alumina
CN118685728A (zh) 一种基于热喷涂技术构筑陶瓷基自润滑、高抗磨、强防腐涂层的方法及应用
Skoneczny Analysis of morphology and microstructure of Al 2 O 3 layers

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE

17P Request for examination filed

Effective date: 20240326

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC ME MK MT NL NO PL PT RO RS SE SI SK SM TR