Journal articles: 'Aluminum oxide coating'

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Filip, Ryszard, Maryana Zagula-Yavorska, Maciej Pytel, Jolanta Romanowska, Mateusz Maliniak, and Jan Sieniawski. "The Oxidation Resistance of Nonmodified and Zr-Modified Aluminide Coatings Deposited by the CVD Method." Solid State Phenomena 227 (January 2015): 361–64. http://dx.doi.org/10.4028/www.scientific.net/ssp.227.361.

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The aim of the present work was to determine the influence of chemical composition of the protective coating on the oxidation resistance of the protected alloy. Zirconium modified and nonmodified aluminide coatings were deposited on the MAR M200 nickel superalloy by the CVD method. The oxidation tests were conducted at 1100°C into 23 hour in the air. The chemical composition (EDS) analysis was performed. The kinetic of oxidation of zirconium modified and nonmodified aluminide coatings was similar. Oxides inclusions called pegs were observed on the surface of oxidized aluminide coating. HfO2 oxide is more stable than Al2O3 oxide, hafnium atoms can replace aluminum atoms in Al2O3 oxides. This phenomena let to stabilize NiAl phase and increase of oxidation resistance of aluminide coating.

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Yu, Mei, Wu Jiang, Jian Hua Liu, and Song Mei Li. "Black Anodized Thermal Control Coating on LY12 Aluminum Alloy." Advanced Materials Research 233-235 (May 2011): 2166–71. http://dx.doi.org/10.4028/www.scientific.net/amr.233-235.2166.

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The black thermal control coatings were prepared by etching anodic oxide film and coloring with an organic ATT dyestuff on the LY12 aluminum alloy. The anodic oxide film on aluminum alloy was formulated in 20% aqueous solution of sulfuric acid in galvanostatic conditions. The microstructure of the anodized coating was studied by scanning electronic microscope (SEM). Open circuit potential (OCP) was applied to study the etching of porous oxide layers in the immerging acid solution. The influence of coloring on the optical properties of the coating was investigated. Results showed that the solar absorptance and infrared emittance increased by increasing coloring times.

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Wen, Yu Qing, Hui Min Meng, Wei Shang, and Xiu Juan Jiang. "Electrochemical Characteristics of the Rare Earth Compound Coating on 6061 Aluminum Alloy." Applied Mechanics and Materials 71-78 (July 2011): 2361–65. http://dx.doi.org/10.4028/www.scientific.net/amm.71-78.2361.

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The composite coatings were prepared on aluminum alloy by anodizing and chemical conversion method. The coatings consisted of a anodic oxide coating and a rare earth conversion coating. The surface morphology and composition of the composite coatings were analyzed by scanning electron microscopy (SEM) and energy dispersive X-rays (EDX). The electrochemical properties of the different samples were researched by Potentiodynamic polarisation and electrochemical impedance spectroscopy in a 3.5-wt.% NaCl solution. The results showed that corrosion current density of the sample with composite coatings was 3.611×10-9 A·cm-2, impedance was 6.107×105 Ω·cm-2. The composite coatings had better corrosion resistance than the sample with anodic oxide film and the aluminum alloy substrate.

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Chan, K. S., N. S. Cheruvu, and G. R. Leverant. "Coating Life Prediction Under Cyclic Oxidation Conditions." Journal of Engineering for Gas Turbines and Power 120, no. 3 (July 1, 1998): 609–14. http://dx.doi.org/10.1115/1.2818189.

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The hot gas path section components of land based turbines require materials with superior mechanical properties and good hot corrosion and oxidation resistance. These components are generally coated with either a diffusion coating (aluminide or platinum aluminide) or with an overlay coating (MCrAlY) to provide additional hot corrosion and/or oxidation protection. These coatings degrade due to inward and outward diffusion of elements during service. Outward diffusion of aluminum results in formation of a protective oxide layer on the surface. When the protective oxide spalls, Aluminum in the coating diffuses out to reform the oxide layer. Accelerated oxidation and failure of coating occur when the Al content in the coating is insufficient to reform a continuous alumina film. This paper describes development of a coating life predictions model that accounts for both oxidation and oxide spallation under thermal mechanical loading as well as diffusion of elements that dictate the end of useful life. Cyclic oxidation data for aluminide and platinum aluminide coatings were generated to determine model constants. Applications of this model for predicting cyclic oxidation life of coated materials are demonstrated. Work is underway to develop additional material data and to qualify the model for determining actual blade and vane coating refurbishment intervals.

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Lukauskaitė, Raimonda, Algirdas Vaclovas Valiulis, and Olegas Černašėjus. "Investigation of Cathodic Cleaning Processes of Aluminum Alloy." Solid State Phenomena 220-221 (January 2015): 684–92. http://dx.doi.org/10.4028/www.scientific.net/ssp.220-221.684.

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On covering aluminum and its alloys with coatings resistant to high-temperature corrosion and attrition, abundant technological problems arise. The key problem is a removal of the film of aluminum oxide Аl2O3 from the aluminum substrate. This permanent, chemically continuous film of oxide reduces adhesion between the substrate and the coating. For improving cohesion of the coating with the substrate, an appropriate pre-treatment of aluminum is required. In the paper, cleaning of aluminum alloy AW 5754 by electric discharge is investigated. This method is considered one of most environmentally friendly methods of surface cleaning. The impact of the parameters of aluminum alloy cathodic cleaning on the surface cleaning width, its roughness and free energy of the surface were examined. In addition, the topography, microstructure and chemical composition of the surface of cleaned aluminum alloy were estimated.

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Monteiro, Sergio Neves, Fabio de Oliveira Braga, Flavio James Tommasini, Artur Camposo Pereira, Andre Ben Hur da Silva Figueiredo, and Fernanda Santos da Luz. "Selective Copper Oxide Coating on Aluminum Panels for Solar Heating Absorption." Materials Science Forum 930 (September 2018): 619–24. http://dx.doi.org/10.4028/www.scientific.net/msf.930.619.

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The efficiency of heating absorption of aluminum sheets coated with copper oxide, CuO, was evaluated in solar panels. Coatings were produced by means of two techniques: vacuum metallic deposition and copper nitrate vaporization onto a pre-heated aluminum sheet. The optical and thermal efficiency of the coatings were evaluated through measurements of the spectral reflectance and surface temperature. The nature of the coating layer was investigated by macro examination. It was found that vacuum deposition presented superior optical efficiency and better adherence. By contrast, coatings produced from vapor are more uniform with higher concentration of CuO.

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Shmorgun, V. G., A. I. Bogdanov, O. V. Slautin, and V. P. Kulevich. "PHASE COMPOSITION OF OXIDE FILMS FORMED ON THE SURFACE OF THE FE-CR-AL SYSTEM COATINGS." IZVESTIA VOLGOGRAD STATE TECHNICAL UNIVERSITY, no. 6(241) (June 29, 2020): 14–18. http://dx.doi.org/10.35211/1990-5297-2020-6-241-14-18.

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The phase composition of the oxide films on the surface of the Fe-Cr-Al system coatings is studied using glancing angle X-ray diffraction. It is shown that at 900 °С the formed oxide films consist of αAlO and (FeCr)O, to which FeAlO oxide is added during long-term exposure. An increase in temperature to 1100 °C intensifies the growth of oxide films, and an increase in the aluminum content ensures a stable growth of αAlO and FeAlO oxides. When the aluminum content in the coating is more than 10 at. % at large exposure times, metastable alumina δAlO is formed, the formation of which is associated with a decrease in the concentration of chromium in thin surface layers.

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Cao, Mei, Zhong Cheng Guo, Xia Cui, and Su Qiong He. "The Study on the Surface Morphology of Al/SnO₂-Sb₂O₃ or SnO₂-Sb₂O₃-MnO₂/PbO₂ Electrode Material." Advanced Materials Research 97-101 (March 2010): 1805–8. http://dx.doi.org/10.4028/www.scientific.net/amr.97-101.1805.

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SnO2–Sb2O3 or SnO2-Sb2O3-MnO2/ PbO2 electrode on aluminum substrate were prepared by thermal decomposition、electroless plating and electrodeposition .The surface morphology of coatings were investigated by using scanning electron microscope(SEM). The results show the effects of composition of solution and thermal oxidation temperature on the microstructures of the coating were considerable. The structure of oxide coating become refined with the thermal de- composition temperature increasing. The oxide coating without Mn is coarser than those with Mn. The surface of α-PbO2 and β-PbO2 deposited on the oxide coatings without Mn prepared at 450°C are compact and even, the electrocatalyst of the electrode is optimumest.

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Malinina, G. A., V. S. Denisova, St S. Solntsev, and M. L. Vaganova. "INVESTIGATION OF THE EFFECT OF OXIDE ADDITIVES ON THE PROPERTIES OF HEAT-RESISTANT GLASS-CRYSTAL COATING." Proceedings of VIAM, no. 5 (2021): 87–95. http://dx.doi.org/10.18577/2307-6046-2021-0-5-87-95.

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Experimental compositions of coatings based on SiO2–Al2O3–MgO matrix glass and modifying additives are considered. A number of refractory metal oxides were selected as modifying additives. The influence of these additives on the properties of the coating melt, such as the spreadability and the wetting edge angle, as well as the oxidability of the resulting compositions, is studied. It was found that the experimental coating modified with aluminum oxide has the best protective properties. The introduction of modifying additives in quantities of more than 5 % is considered inappropriate.

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Vaidya, K. J., and L. F. Francis. "Processing of calcium metaphosphate-based glass-ceramic coatings on alumina." Journal of Materials Research 11, no. 1 (January 1996): 100–109. http://dx.doi.org/10.1557/jmr.1996.0013.

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Dense, crystalline, glass-ceramic coatings containing calcium metaphosphate and aluminum phosphate were prepared on aluminum oxide substrates by a three-step method. The processing involved glass (40 mol% CaO, 10 mol% Al2O3, 50 mol% P2O5) formation, deposition of a glass particle coating, and heat treatment to sinter the glass and crystallize the phosphates. Sintering and microstructure evolution were influenced by wet coating thickness, heat-treatment temperature, time, and heating rate. Heat treatment for 1 h at 725 °C using a 50 °C/min heating rate was found to give a dense, crack-free coating. The resultant coating microstructure has spherulitic morphology (0.3 μm size) with aluminum phosphate in the center of the spherulite. The hardness of the fully crystallized glass-ceramic coating was ∼5.2 GPa.

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Villarreal, Iván, Miguel Aldás, Victor Hugo Guerrero-Barragan, Nelly María Rosas-Laverde, and Alexis Debut. "CaO stabilized ZrO2 coating intended to reduce corrosion on steel and aluminum substrates." Superficies y Vacío 30, no. 2 (June 15, 2017): 14–20. http://dx.doi.org/10.47566/2017_syv30_1-020014.

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In this work, we studied the anticorrosive properties of sol-gel nanostructured calcium stabilized zirconia coatings, deposited onto 304 stainless steel and commercial aluminum substrates by dip-coating and spin-coating. During the ceramic oxide synthesis, zirconium oxychloride octahydrate was used as precursor and calcium acetate monohydrate was used as stabilizer of the cubic zirconia structure, in a precursor/stabilizer molar ratio of 0.84/0.16. The gel films deposited on steel and aluminum were heat treated at 550 y 600 °C during 5 and 10 min, respectively, and the adherence of the resulting ceramic films was evaluated. Continuous coatings were obtained that reached average thicknesses between 2 y 3 mm when deposited on stainless steel, and between 1.5 y 1.6 on aluminum, depending on the coating method. The corrosion resistance of the best-adhered coatings was evaluated during 500 h in a saline chamber, according to ASTM B117-11. All the substrate-coating combinations showed a very good corrosion resistance. For the two substrate types, the films deposited by dip-coating showed higher corrosion resistance than the ones deposited by spin-coating. The anticorrosive protective effect of the coatings was better for the aluminum substrates, compared to the stainless-steel substrates.

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Yin, Yu Jun, Shu Hua Li, Da Wei Shen, Yuan Yuan Zu, and Chang Zheng Qu. "Effects of Al₂O₃ Nanoparticles on Microstructure and Performance of Ceramic Coatings by Micro-Arc Oxidation." Key Engineering Materials 537 (January 2013): 92–96. http://dx.doi.org/10.4028/www.scientific.net/kem.537.92.

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A dense ceramic oxide coating approximately 45 µm thick was prepared on a Ly12 aluminum alloy by micro-arc oxidation in an alkali-phosphate electrolytic solution. Coating thickness and surface roughness (Ra) were measured after the coating had been synthesized. The effects of Al2O3 Nanoparticles in electrolyte on phase composition, microstructure and microhardness of the micro-arc oxidation ceramic coatings on Ly12 aluminum alloy were investigated by means of XRD, SEM and hardness experimentation. The results show that the ceramic coatings become more dense and its microhardness increased by adding Al2O3 Nanoparticles in electrolyte. In addition, the roughness of the micro-arc oxidation ceramic coatings is obviously improved by addition of Al2O3 Nanoparticles.

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13

Gusev, V. M., O. Yu Elagina, and A. G. Buklakov. "Improving the properties of plasma heat-resistant coatings by means of spraying materials that reacting with exothermic effects." Physics and Chemistry of Materials Treatment 2 (2021): 51–55. http://dx.doi.org/10.30791/0015-3214-2021-2-51-55.

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The quality of heat-resistant coatings deposited by flame spraying is largely determined by the adhesion of the coating to the surface of the part. One of the ways to increase adhesion is to deposition intermediate layers of thermosetting powders between the base material and the coating. In this work, two versions of heat-protective coatings are investigated — a two-layer coating consisting of an Al – Ni sublayer (20 – 80 wt. %) and a main ZrO2 layer, and a single-layer coating sprayed from an aluminum-clad zirconium oxide powder (20 ZrO2 – 80 Al, wt. % ). The method of differential thermal analysis was used to determine the temperature ranges and values of the exothermic effects of oxidation and redox reactions during heating of Al – Ni and ZrO2 clad powders. A significant exothermic effect was found during oxidation of the aluminum cladding shell in the temperature range of 360 °C and a stronger thermal effect due to the redox reaction at a temperature of 920 °C. The microstructure and microhardness of the obtained coatings have been studied, and their thermal conductivity and adhesion have been assessed. The resistance of the coatings during thermal cycling tests has been determined. It has been established that thermal protective coatings made of aluminum-clad zirconium oxide powder have the best characteristics under thermal cycling conditions. A higher level of adhesion and thermal cyclic resistance of such coatings are due to an increase in the enthalpy of aluminum-clad ZrO2 powders due to exothermic reactions and the presence of a metal binder.

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Cheruvu, N. S., K. S. Chan, and G. R. Leverant. "Cyclic Oxidation Behavior of Aluminide, Platinum Modified Aluminide, and MCrAlY Coatings on GTD-111." Journal of Engineering for Gas Turbines and Power 122, no. 1 (October 20, 1999): 50–54. http://dx.doi.org/10.1115/1.483174.

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Cyclic oxidation behavior of aluminide, platinum modified aluminide, and MCrAlY coatings has been investigated at three temperatures. Aluminide and platinum modified coatings were deposited on GTD 111 material using an outward diffusion process. CoCrAlY coating was applied on GTD-111 by Electron Beam Physical Vapor Deposition (EB-PVD). The oxidation behavior of these coatings is characterized by weight change measurements and by the variation of β phase present in the coating. The platinum modified aluminide coating exhibited the highest resistance to oxide scale spallation (weight loss) during cyclic oxidation testing. Metallographic techniques were used to determine the amount of β phase and the aluminum content in a coating as a function of cycles. Cyclic oxidation life of these coatings is discussed in terms of the residual β and aluminum content present in the coating after exposure. These results have been used to calibrate and validate a coating life model (COATLIFE) developed at the Material Center for Combustion Turbines (MCCT). [S0742-4795(00)00801-2]

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Egorkin, Vladimir S., Ivan M. Medvedev, Sergey L. Sinebryukhov, Igor E. Vyaliy, Andrey S. Gnedenkov, Konstantine V. Nadaraia, Nikolaj V. Izotov, Dmitriy V. Mashtalyar, and Sergey V. Gnedenkov. "Atmospheric and Marine Corrosion of PEO and Composite Coatings Obtained on Al-Cu-Mg Aluminum Alloy." Materials 13, no. 12 (June 17, 2020): 2739. http://dx.doi.org/10.3390/ma13122739.

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Wrought Al-Cu-Mg aluminum alloy (D16) was treated by bipolar plasma electrolytic oxidation to create a base plasma electrolytic oxidation (PEO)-coating with corrosion protection and mechanical properties superior to bare alloy’s natural oxide layer. Additional protection was provided by the application of polymer, thus creating a composite coating. Electrochemical and scratch tests, scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction studies were performed. Degradation of coatings in the marine atmosphere and seawater was evaluated. The composite polymer-containing coating provided better corrosion protection of aluminum alloy compared to the PEO-coating, although seawater affected both. During the atmospheric exposure, the PEO-coating provided reasonably good protection, and the composite coating showed excellent performance.

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Grote, Fabian, Huaping Zhao, and Yong Lei. "Self-supported carbon coated TiN nanotube arrays: innovative carbon coating leads to an improved cycling ability for supercapacitor applications." Journal of Materials Chemistry A 3, no. 7 (2015): 3465–70. http://dx.doi.org/10.1039/c4ta05905k.

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Innovative carbon coating on nano-porous anodic aluminum oxide templates enables coatings on dense self-supported nanostructured arrays in a reverse manner for applications in energy devices (e.g., supercapacitors).

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Egorkin, Vladimir S., Ulyana V. Kharchenko, Nikolay V. Izotov, Igor E. Vyaliy, Andrey S. Gnedenkov, Dmitry K. Tolkanov, Andrey K. Runov, Alexander N. Minaev, Sergey L. Sinebryukhov, and Sergey V. Gnedenkov. "Morphology and Chemical Composition of Organic Coatings Formed Atop PEO-Layers." Solid State Phenomena 312 (November 2020): 325–29. http://dx.doi.org/10.4028/www.scientific.net/ssp.312.325.

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The plasma electrolytic oxidation (PEO) process was used to form an oxide layer on an Al5754 aluminum alloy for subsequent application of organic coating. The effect of the oxidation time on the morphology and anticorrosion properties of PEO-coatings was investigated. The oxide layer possess low apparent porosity and provides high adhesion to the paint. The resulting composite coating (CC) is characterized by high barrier properties in chloride solution.

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Chiba, Makoto, Chinami Yamada, Haruka Okuyama, Minori Sugiura, Sven Pletincx, Hilke Verbruggen, Atsushi Hyono, Iris De Graeve, Herman Terryn, and Hideaki Takahashi. "Development of novel surface treatments for corrosion protection of aluminum: self-repairing coatings." Corrosion Reviews 36, no. 1 (February 23, 2018): 55–64. http://dx.doi.org/10.1515/corrrev-2017-0056.

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AbstractTwo types of self-repairing coatings for the protection of Al and its alloys are reviewed: (1) organic coatings with capsules containing repairing agent and (2) porous anodic oxide films with inhibitor solution stored in the pores of the oxide film. First, polyurethane microcapsules containing liquid surface-repairing agents were synthesized and polyurethane coating with the capsules was painted on Al alloy specimens. After mechanical damage to the coating, self-repairing occurred by the reaction of water vapor in the air with the repairing agents released from the capsules. Second, porous-type anodic oxide films were formed on Al alloys, and the pores of the anodic oxide films were filled with inhibitor solutions, followed by application of a covering polyurethane layer. Inhibitors released from the pores efficiently protected the Al alloy substrate from corrosion arising from induced mechanical damage.

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Auzins, Krisjanis, Aleksejs Zolotarjovs, Ivita Bite, Katrina Laganovska, Virginija Vitola, Krisjanis Smits, and Donats Millers. "Production of Phosphorescent Coatings on 6082 Aluminum Using Sr0.95Eu0.02Dy0.03Al2O4-δ Powder and Plasma Electrolytic Oxidation." Coatings 9, no. 12 (December 16, 2019): 865. http://dx.doi.org/10.3390/coatings9120865.

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In this study, a new approach for producing phosphorescent aluminum coatings was studied. Using the plasma electrolytic oxidation (PEO) process, a porous oxide coating was produced on the Al6082 aluminum alloy substrate. Afterwards, activated strontium aluminate (SrAl2O4: Eu2+, Dy3+) powder was filled into the cavities and pores of the PEO coating, which resulted in a surface that exhibits long-lasting luminescence. The structural and optical properties were studied using XRD, SEM, and photoluminescence measurements. It was found that the treatment time affects the morphology of the coating, which influences the amount of strontium aluminate powder that can be incorporated into the coating and the resulting afterglow intensity.

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Goleus, V., and A. Salei. "Effect of Transition Metals Oxide Additives on the Properties of Mixed-Alkali Glass for Electric Insulating Coatings on Aluminum." Фізика і хімія твердого тіла 20, no. 3 (October 18, 2019): 300–305. http://dx.doi.org/10.15330/pcss.20.3.300-305.

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In order to reduce the cost of the thick-film technology of microcircuits and heating elements, as well as to expand its areas of use, it became necessary to expand the range of materials that, along with ceramics and steel, can also be used as substrates for these products. One of these advanced materials is aluminum. Electrically insulated coatings on metals are subjected to repeated heating and cooling while their produce and use, which promotes the creation of temperature stresses in the coating and leads to their chipping. Therefore, in order to improve the water resistance and adhesion strength of electrical insulation coatings on aluminum, CuO, ZrO2 and Bi2O3 additives were examined. There was found an increase in water resistance with a simultaneous increase in the adhesion strength of the enamel coating with an aluminum substrate with the addition of not more than 3 pts. wt. of copper oxide (II), up to 1 pts. wt. of zirconium oxide (IV), and up to 4 pts. wt. of bismuth oxide (III) w.r.t. 100 pts. wt. of glass.

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Wang, Yun, Ji Kang Yan, Guo You Gan, Jing Hong Du, and Jian Hong Yi. "Thermodynamic Analysis of Aluminum Oxide-Coated Titanium Didoxide." Advanced Materials Research 412 (November 2011): 410–14. http://dx.doi.org/10.4028/www.scientific.net/amr.412.410.

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In order to improve the dispersion of TiO2, use the surface coating technology to form the aluminium ion film on the surface of TiO2, so as to achieve the aim of modification. Use the aqueous solution sedimentary drying method to make the alumina coating experiment under as certain technical condition, use the test like the scanning electron microscopy and transmission electron microscope, etc to analyze the coating powder’s dispersive and coating situation. The paper started from the angle of ion sedimentary reaction equilibrium, made the thermodynamics analysis on the coating on the surface of TiO2 and got the [Al]T-pH relationship diagram about the aluminium ion, and then confirm the PH extent for the aluminium ion’s completed sedimentation. The result indicated that, when the PH value reached from 8 to 12, the aluminium ion would completely precipitate.

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Pietrzyk, Bożena, Daniel Kucharski, Łukasz Kołodziejczyk, Sebastian Miszczak, and Mateusz Fijalkowski. "Comparison of Mechanical and Barrier Properties of Al2O3/TiO2/ZrO2 Layers in Oxide–Hydroxyapatite Sandwich Composite Coatings Deposited by Sol–Gel Method on Ti6Al7Nb Alloy." Materials 13, no. 3 (January 21, 2020): 502. http://dx.doi.org/10.3390/ma13030502.

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In this study, coatings of different oxides (TiO2, Al2O3, ZrO2) and hydroxyapatite (HAp) as well as sandwich composite hydroxyapatite with an oxides sublayer (oxide+HAp) were deposited on Ti6Al7Nb alloy using the sol–gel dip-coating method. The coatings were characterized in terms of morphology (optical microscope), surface topography (AFM), thickness (ellipsometry), and crystal structure (XRD/GIXRD). The mechanical properties of the coatings—hardness, Young’s modulus, and adhesion to the substrate—were examined using nanoindentation and scratch tests. The barrier properties of the coatings against the migration of aluminum ions were examined by measuring their concentration after soaking in Hank’s balanced salt solution (HBSS) with the use of optical emission spectrometry of inductively coupled plasma (ICPOES). It was found that all the oxide and HAp coatings reduced the permeation of Al ions from the Ti6Al7Nb alloy substrate. The best features revealed an Al2O3 layer that had excellent barrier properties and the best adhesion to the substrate. Al2O3 as a sublayer significantly improved the properties of the sandwich composite HAp coating.

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Susilawati, Susilawati, Aris Doyan, Lalu Muliyadi, and Syamsul Hakim. "Growth of Tin Oxide Thin Film by Aluminum and Fluorine Doping Using Spin Coating Sol-Gel Techniques." Jurnal Penelitian Pendidikan IPA 6, no. 1 (October 14, 2019): 1. http://dx.doi.org/10.29303/jppipa.v6i1.264.

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Abstract: The growth of tin oxide thin film by Aluminum doping and Fluorine has been carried out with the sol-gel spin coating technique. The growth aims to determine the quality of the thin layer formed based on variations in doping aluminum and fluorine. The basic ingredients used were SnCl2.2H2O, while the doping materials used were Al (Aluminium) and F (Fluorine) with variations in dopant concentrations (0, 5, 10, 15, 20 and 25)%. The growth of a thin layer using measured glass (10x10x 3) mm as a substrate. The growth of thin films includes substrate preparation, sol-gel making, thin film making, and heating processes. The growth of thin layer was dripped on a glass substrate with sol-gel spin coating technique at 1 M sol concentration and treated with maturation for 24 hours. The next step is making a thin layer using a spin coater at a speed of 2000 rpm for 3 minutes. After that, the substrate is heated in an oven at 100°C for 60 minutes. The results showed that the transparency level of the tin oxide layer increases with increasing amounts of doping Aluminum and fluorine. Key words: Aluminum, Fluorine, Sol-gel, Spin Coating, Thin Film, Tin Oxide

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Lou, Hao-Ren, Dah-Shyang Tsai, and Chen-Chia Chou. "Correlation between Defect Density and Corrosion Parameter of Electrochemically Oxidized Aluminum." Coatings 10, no. 1 (December 27, 2019): 20. http://dx.doi.org/10.3390/coatings10010020.

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It has been recognized that a connection may exist between defects of oxide coating and its corrosion protection. Such a link has not been substantiated. We prepare two coatings of anodized aluminum oxide (AAO) and plasma electrolytic oxidation (PEO), and analyze them with Mott-Schottky plots and potentiodynamic polarization scans. The as-grown and annealed AAO coatings exhibit both p-type and n-type semiconductor behaviors. Polarization resistance of the AAO coating increases from (1.8 ± 1.7) × 108 to (4.3 ± 0.5) × 108 Ω·cm2, while corrosion current decreases from (6.1 ± 3.6) × 10−7 to (2.3 ± 0.9) × 10−7 A·cm−2, as annealing temperature increases from room temperature to 400 °C. The parameter analysis on AAO indicates a positive correlation between corrosion current and donor density, a negative correlation between polarization resistance and donor density. The attempt on correlating corrosion potential gives rise to considerable deviation from a linear fit. The results suggest protection of AAO hinges on its donor density, not acceptor. On the PEO coatings, only the n-type behavior is observed. Intriguingly, the donor density of PEO coating is influenced by the annealing temperature of its pre-anodized layer. The most resistant PEO coating, with pre-anodized and 400 °C annealed AAO, exhibits polarization resistance (2.1 ± 0.4) × 109 Ω·cm2 and corrosion current (1.7 ± 0.4) × 10−8 A·cm−2.

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Lou, Bai Yang, Guo Zhu, Pei Hua Li, and Han Shan Dong. "Study on Corrosion Wear Behavior of 70 Aluminum Alloy Anodic Oxide Coating." Advanced Materials Research 652-654 (January 2013): 1735–38. http://dx.doi.org/10.4028/www.scientific.net/amr.652-654.1735.

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In vitriolic electrolyte, DC power supply is used on 7075 aluminum alloy to have anodic oxidation treatment then let the oxidized samples have a treatment of electroless plating. Surface morphology of the coating and performance of corrosion wear are studied by means of scanning electron microscope (SEM) and friction and wear experimental machine. The results show that unsealed oxide coating have many holes and cracks, which are extremely badly-distributed; corrosion resistance of the oxide coatings which have the treatment of electroless plating have improved, having lower coefficient of friction and better performance of corrosion wear; besides; coefficient of friction of the samples in water is higher than that in salt water, its wear amount is less.

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He, Yan Hong, Zhen Duo Cui, Xian Jin Yang, Sheng Li Zhu, Zhao Yang Li, and Yan Qin Liang. "Corrosion Behavior and Microstructure of Pd Ions Doped Cerium Conversion Coating on AA2219-T87 Aluminum Alloy." Advanced Materials Research 1090 (February 2015): 79–83. http://dx.doi.org/10.4028/www.scientific.net/amr.1090.79.

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In this paper, Pd ions doped cerium conversion coating (CeCC/Pd) was deposited on AA2219-T87 aluminum alloy by electroplating. The microstructure and composition of the coating were characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS). Corrosion behavior of AA2219-T87 aluminum alloy with the coating was investigated in 3.5wt.% NaCl solution at the room temperature. XRD and XPS results indicate the existence of cerium-oxide and palladium-oxide in the CeCC/Pd. Polarization curves show that the CeCC/Pd exhibits excellent corrosion resistance. The corrosion current density of the CeCC/Pd decreases by two orders of magnitude compared with the CeCC. The improvement of corrosion resistance would be attributed to the small grain size, good compactness and adhesive strength of the composite coatings.

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Opsal Bakke, Aina, Arne Nordmark, Lars Arnberg, and Yanjun Li. "Interfacial microstructure formation in A356/steel compound castings using metal coating." MATEC Web of Conferences 326 (2020): 06005. http://dx.doi.org/10.1051/matecconf/202032606005.

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Compound castings between aluminum and steel have great potential for applications in the automotive industry. However, due to large differences in thermal and mechanical properties between steel and aluminum, and the formation of stable aluminum oxides at the interface, it is difficult to form high strength metallic bonding between the two metals. In this work, A356/steel compound castings were produced through a gravity casting process. Various metal coatings, including galvanizing, aluminizing and brass-coating, were applied on the steel inserts to ensure that the A356 aluminum melt could react sufficiently with an oxide-free steel surface, resulting in a high-quality metallurgical bond. The reaction layer formed between the alloys was investigated using Optical Microscopy (OM), Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDS). In addition, Vickers Micro-hardness was measured across the aluminum-steel interface. Results showed that metallurgical bonding could be achieved with all three coatings. However, for the brass-coated components only local bonding areas were found. In the aluminized and galvanized components, thick reaction layers consisting of binary Al-Fe and ternary Al-Fe-Si phases formed in the aluminum-steel interface. Between the A356 aluminum and aluminized layer, nearly no reaction layer formed. The mechanism for the formation of the various intermetallic phases at the reaction layers are discussed.

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Filonina, Valeriia S., Konstantine V. Nadaraia, Dmitry V. Mashtalyar, Andrey S. Gnedenkov, Igor M. Imshinetsky, Andrey P. German, Igor E. Vyaliy, et al. "Formation of Protective Coatings on AMg3 Aluminum Alloy Using Fluoropolymer Nanopowder." Solid State Phenomena 312 (November 2020): 330–34. http://dx.doi.org/10.4028/www.scientific.net/ssp.312.330.

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The paper presents the results of a study of the protective properties of composite coatings obtained on AMg3 aluminum alloy by plasma electrolytic oxidation (PEO) and subsequent modification of formed oxide layer with superdispersed polytetrafluoroethylene (SPTFE) from a suspension based on isopropyl alcohol. The incorporation of fluoropolymer decreased the porosity of base PEO-coating more than one order of magnitude. Formed composite layers increased wearproof of the samples by more than two orders of magnitude in comparison with PEO-coating. Additionally, polymer-containing coatings has higher adhesion compared to substrate. Formed composite layers possess superhydrophobic properties: contact angle attains 155°.

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Steiger, Rolf, Robert Beer, J. F. Fernandez-Sanchez, and U. E. Spichiger-Keller. "Large Area, Nanoparticulate Metal Oxide Coatings for Consumer Nanotechnologies." Solid State Phenomena 121-123 (March 2007): 1193–98. http://dx.doi.org/10.4028/www.scientific.net/ssp.121-123.1193.

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Large area coatings containing nanoparticulate metal oxides dispersed in polymers are manufactured at high speed (up to 200 m2 /min.) by curtain- or cascade coating on flexible substrates near room temperature. Simultaneously coated multilayers, which may contain different metal oxides, show interesting new properties for industrial applications. Thick (40 $m) coatings with rare-earth doped aluminum oxide nanoparticles have been commercialized for waterfast ink-jet media which are dry to touch after printing, show photo-parity and are very stable towards water, light and environment if appropriate inks are used. Strong capillary forces due to nanoporosity allow instant ink-absorption. Experimental techniques used to develop these materials and results related to imaging parameters are discussed. Thin layers (1-10 $m) of nanoparticulate, nanoporous TiO2 and LiMn2O4, dispersed in non-electroactive polymers such as polyethylene glycols, can be used as electrodes for rechargeable Li-ion batteries with very fast charge-discharge cycles and high power performance. The excellent ion-conducting properties of unsintered, nanoparticulate coatings of these metal oxides were unexpected and allow applications of temperature sensitive substrates and organic addenda. By coating very thin, almost or totally polymer-free layers of highly-porous, monodisperse aluminum-oxides with minimum particle size, display devices with improved optical efficiency were prepared. These layers have a low refractive index thus allowing for higher intensities of light emitted by organic electro-luminescers in OLED’s and PLED’s. This property is useful for mobile devices as phones and PDA’s. A hitherto unknown, photo-catalytic chemical reaction of the classical green emitter tris-(8-hydroxychinolino)-aluminum (Alq3) has been discovered in coatings of such optically efficient devices after exposing them to daylight in air. An efficient blue-emitting species of Alq3 with another stereochemical structure was directly formed within these layers at room temperature by photolysis in ambient atmosphere. Interesting new applications of specially designed, large-area coated and transparent nanostructured matrices on flexible substrates for optical gas sensors are discussed in more detail in this paper.

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Manoj, Aluri, M. M. Basha, S. M. Basha, and M. R. Sankar. "A Review - Black Oxide Coating on Metal Substrates of Steels, Aluminium, Magnesium and Copper." Advances in Science and Technology 106 (May 2021): 46–53. http://dx.doi.org/10.4028/www.scientific.net/ast.106.46.

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Aluminium, magnesium, copper, steels and their alloys are generally used in vast applications like automobile, ship, architecture, aerospace due their properties of high strength to weight ratio, good toughness, ease of recycling and good thermal conductivity. In practical applications, surface treatment is required to meet design requirements and also improves the long-term corrosion resistance and functionality. To enhance surface properties electro deposition, sol-gel, anodization and gas phase deposition are causally used in many industries. For achieving better results, one of the alternative coating has been developed such as black coating to modify the metal substrate properties. These black coating can be prepared by conventional method as well as other methods like micro arc oxidation, plasma electrolytic oxidation and pulse micro arc oxidation techniques. Conventional coloring method shows some disadvantages, for instance, poisonous Cr6+ ions are formed while preparing black oxide coating by conversion of chromium. To avoid such disadvantages, micro arc oxidation, plasma electrolytic oxidation and pulse micro arc oxidation are developed. Based on these techniques, surface properties like long-term corrosion resistance, wear resistance, biocompatibility and decoration are enhanced. Black coatings have high hardness, good bonding with metal substrate, light aging resistance and higher thickness of coating due to strongest absorption ability. This paper mainly focusses the generation of black oxide coating on steel, aluminum, magnesium and copper.

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Chilimoniuk, Paulina, Robert P. Socha, and Tomasz Czujko. "Nanoporous Anodic Aluminum-Iron Oxide with a Tunable Band Gap Formed on the FeAl3 Intermetallic Phase." Materials 13, no. 16 (August 6, 2020): 3471. http://dx.doi.org/10.3390/ma13163471.

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Nanostructured anodic oxide layers on an FeAl3 intermetallic alloy was prepared by two-step anodization in 20 wt.% H2SO4 at 0 °C. The obtained anodic oxide coating was subjected to phase and chemical composition analysis using XPS and XRD techniques. An analysis of the band gap of individual coatings was also performed. The applied parameters of the anodization process were determined, enabling the formation of a nanostructured coating on the FeAl3 intermetallic alloy. Tests were carried out on samples produced at a voltage between 10 V and 22.5 V in 2.5 V steps. The produced coatings were subjected to an annealing process at 900 °C for 2 h in an argon protective atmosphere. Moreover, the influence of the substrate chemical composition on the chemical and phase composition of the anodic oxide are discussed. Band gaps of 2.37 eV at 22.5 V and 2.64 eV at 10 V were obtained directly after the anodizing process. After applying the heat treatment, band gap values of 2.10 eV at 22.5 Vand 2.48 eV for the coating produced at 10 V were obtained.

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Li, Shu Hua, Yu Jun Yin, Da Wei Shen, Yuan Yuan Zu, and Chang Zheng Qu. "Tribological Performance of Ceramic Composite Coatings Obtained through Microarc Oxidation on Ly12 Aluminum Alloy." Key Engineering Materials 537 (January 2013): 7–11. http://dx.doi.org/10.4028/www.scientific.net/kem.537.7.

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A dense ceramic oxide coating approximately 30µm thick was prepared on a Ly12 Al alloy by microarc oxidation in an alkali-silicate electrolytic solution. The morphology and microstructure were analyzed by scanning electron microscope (SEM) and X-ray diffraction (XRD). Coating thickness and surface roughness (Ra) were measured after the coating had been synthesized. The tribological performance of the coatings was evaluated using a dry sand abrasion test and a solid particle erosion test. The results show that microarc oxidation coatings consist of the loose superficial layer and the inner dense layer. Both inner layer and out layer are composed of α-Al2O3 and γ-Al2O3, While the Al6Si2O3 phase is observed only in out loose layer. The average of the microhardness of the coating is 2096Hv.

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Kiseleva, S. K., L. I. Zaynullina, and N. Y. Dudareva. "Influence of the Microstructure Al-12%Si Alloy on the Properties of the Oxide Layer Formed with MAO." Materials Science Forum 870 (September 2016): 481–86. http://dx.doi.org/10.4028/www.scientific.net/msf.870.481.

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The quality of coating on the high-silicon aluminum alloy Al-12%Si depending on the initial microstructure of the samples has been investigated. The method of microarc oxidation (MAO) has been used for coating. The quality of coating was evaluated by the thickness and microhardness of the formed layer. The initial microstructure of aluminum alloy samples was varied by distribution of silicon particles in the volume of the matrix solution. The possibility of obtaining a high-hardness protective coating on the alloy Al-12%Si by the MAO method has been shown. The influence of the alloy microstructure on the microhardness and thickness of coatings has been established. It has been shown that the deformation thermal treatment of Al-12%Si alloy samples before MAO leads to deterioration in the quality of the formed layer. A model of the influence of the silicon particles distribution on the quality of the micro-layer has been represented for explanation of the observed effect. The increase of microhardness in coatings with a greater thickness has been revealed.

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Czupryński, A. "Selected Properties Of Thermally Sprayed Oxide Ceramic Coatings." Advances in Materials Science 15, no. 3 (September 1, 2015): 17–32. http://dx.doi.org/10.1515/adms-2015-0012.

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Abstract The article presents the results of the study on exploitation properties of flame sprayed ceramic coatings produced by oxide ceramic material in the form of powder on the aluminum oxide Al2O3 matrix with 3% titanium oxide TiO2 addition and also on the zirconium oxide (ZrO2) matrix with 30% calcium oxide (CaO) on the substrate of unalloyed structural steel of S235JR grade. As a primer powder, metallic powder on the base of Ni-Al-Mo has been applied. Plates with dimensions of 5×200×300 mm and also front surfaces of ∅40×50 mm cylinders have been flame sprayed. Spraying of primer coating has been done using RotoTec 80 torch and external specific coating has been done with CastoDyn DS 8000 torch. Investigations of coating properties are based on metallography tests, phase composition research, measurement of microhardness, coating adhesion to the ground research (acc. to EN 582:1996 standard), abrasive wear resistance (acc. to ASTM G65 standard) and erosion wear resistance (acc. to ASTM G76-95 standard) and thermal stroke study. Performed tests have shown that the flame spraying with 97%Al2O3 powder containing 3% TiO2 and also by the powder based on zirconium oxide (ZrO2) containing 30% calcium oxide (CaO) performed in a wide range of technological parameters allow to obtain high quality ceramic coatings with thickness up to ca. 500 μm on a steel substrate. The primer coating sprayed with the Ni-Al-Mo powder to the steel substrate and external coatings sprayed has the of mechanical bonding character. The coatings are characterized by high adhesion to the substrate and also high erosion and abrasive wear resistance and the resistance for cyclic thermal stroke.

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Hao, Jian Min, Dong Xiao Li, Hong Chen, and Lian Ping Li. "Preparing of Army-Green Ceramic Coating on LY12 Alloy and the Study of Fastness to Ultraviolet Light." Advanced Materials Research 306-307 (August 2011): 746–49. http://dx.doi.org/10.4028/www.scientific.net/amr.306-307.746.

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In this paper, army-green ceramic coating has been obtained by Micro-arc Oxidation, a study of the effects of terminal voltage and colored salt concentration on the thickness, chromaticity and luminance has been made. The performance of anti-aging performance to ultraviolet light of the coatings and anodized oxide film on aluminum by electrolytic coloring was investigated. The thickness, chromaticity ,luminance of the coating were measured .The best sample was obtained at the terminal voltage of 360V and the colored salt concentration of 15g/L, the anti-aging of the army-green coatings to ultraviolet light is apparently better than that of the anodized oxide film by electrolytic coloring.

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Sobolev, Alexander, Israel Wolicki, Alexey Kossenko, Michael Zinigrad, and Konstantin Borodianskiy. "Coating Formation on Ti-6Al-4V Alloy by Micro Arc Oxidation in Molten Salt." Materials 11, no. 9 (September 4, 2018): 1611. http://dx.doi.org/10.3390/ma11091611.

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Micro Arc Oxidation (MAO) is an electrochemical surface treatment process to produce oxide protective coatings on some metals. MAO is usually conducted in an aqueous electrolyte, which requires an intensive bath cooling and leads to the formation of a coating containing impurities that originate in the electrolyte. In the current work, we applied an alternative ceramic coating to the Ti-6Al-4V alloy using the MAO process in molten nitrate salt at a temperature of 280 °C. The obtained coating morphology, chemical and phase composition, and corrosion resistance were investigated and described. The obtained results showed that a coating of 2.5 µm was formed after 10 min of treatment, containing titanium oxide and titanium‒aluminum intermetallic phases. Morphological examination indicated that the coating is free of cracks and contains round, homogeneously distributed pores. Corrosion resistance testing indicated that the protective oxide coating on Ti alloy is 20 times more resistive than the untreated alloy.

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Korzekwa, Joanna, Elżbieta Bociąga, and Dariusz Bochenek. "Investigation of Selected Polymer Composite-Aluminum Oxide Coating Tribological Systems." Materials 13, no. 23 (December 2, 2020): 5491. http://dx.doi.org/10.3390/ma13235491.

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The tribotesting of friction systems requires discussion on proper selection of its conditions and data presentation. System tribology is based, for example, on analysis of the friction contact, the roughness of the cooperating surfaces, and the wear rate of the rubbing elements or coefficient of friction in relation to the sliding distance. Friction pairs, consisting of an aluminum alloy sample with an oxide layer (Al2O3) with and without the addition of inorganic fullerenes like tungsten disulphide (IF-WS2) nanoparticles on its surface cooperating with a counter-sample made of polymer composites prepared on the basis of phenol-formaldehyde resin with different fillers, were tested using a device with a pin-on-plate friction pair system. The results of the experiments showed sufficient durability of the Al2O3 and Al2O3/IF-WS2 oxide coatings in combination with the polymer composite. It was found that resin fillers such as cotton fibers, jute fibers, molybdenum disulphide (MoS2) or graphite (C) influence the friction behavior of the tribological pairs. Although the values of the coefficient of friction obtained in the tests were quite high, their course during the tests ensured stable cooperation of the aluminum coating/polymer composite friction pair on a 15 km distance, under a load of 0.5 MPa. The lowest coefficients of friction were obtained for oxide layers formed on aluminum combined with a polymer composite filled with cotton fibers and graphite. These studies provide information on the tribological properties of commercially available polymer composites cooperating with the produced oxide coatings, supplementing the available literature with the results of research on new, so far unexplored tribological partners. Microscopic investigation of the structure and morphology of the formed surface oxide layers and also microgeometry studies of both the friction elements were used to better understand the obtained research results.

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Rudnik, Ewa, Tomasz Jucha, Lidia Burzynska, and Krzysztof Ćwięka. "Electro- and Electroless Deposition of Ni/SiC and Co/SiC Composite Coatings on Aluminum." Materials Science Forum 690 (June 2011): 377–80. http://dx.doi.org/10.4028/www.scientific.net/msf.690.377.

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Aluminum and its alloys characterize usually poor superficial properties. To improve hardness and wear resistance, aluminum base materials are covered by protective layers. Deposition of metallic coatings on aluminum is accompanied by some difficulties due to tenacious oxide layer present on the substrate surface. Hence, some additional stages are needed to assure good adhesion of the coating to the substrate. In many cases, electrodeposition and electroless methods are competitive for providing deposits with ceramic particles uniformly incorporated within the metal layer. The most extensive studies were carried out on deposition of Ni/SiC composites, but no attempts on Co/SiC coatings deposition on aluminum have been performed. Experiments presented were conducted to develop simply methods for deposition of Ni/SiC and Co/SiC composite coatings on aluminum substrate. The consecutive stages of the hydrometallurgical route were: zincating of aluminum in alkaline solutions, electroless nickel (cobalt) deposition and electrodeposition or electroless deposition of the composite coating. The influence of deposition time and composition of the baths on thickness and composition of the deposits was studied. Microstructure and microhardness of as-plated individual layers were also determined.

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Xu, Ji Hui, Xin Wang, Jing Wang, and Qiu Ju Zheng. "Study on Technological Process of Cerium-Based Conversion Coating on Aluminum." Advanced Materials Research 79-82 (August 2009): 879–82. http://dx.doi.org/10.4028/www.scientific.net/amr.79-82.879.

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The Cerium-based conversion coating is formed on the industrial aluminum(1060) by using chemical immersion. The microstructures of the conversion coating have been examined by scanning electron microscopy(SEM). The electrochemical measurement result shows that the corrosion resistance of aluminum is significantly improved after the conversion coating was formed. The result of X-ray photoelectron spectroscopy (XPS) shows that the cerium conversion coating mainly consisted of oxide of aluminum, CeO2 and TiO2. The formation mechanism of the Cerium-based conversion coating is investigated.

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Udayashankar, N. K., S. Rajasekaran, and Jagannath Nayak. "The Effect of Protective Coatings on the Oxidation Behavior of 6061Al/SiC Composite at High Temperatures." Advanced Materials Research 383-390 (November 2011): 3949–53. http://dx.doi.org/10.4028/www.scientific.net/amr.383-390.3949.

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This paper analyses the effect of protective coatings on the oxidation behavior of 6061Al/SiC composite material at temperatures ranging from 500 to 800 K. Aluminum and AlCrN coatings are employed as protective coatings in order to improve the oxidation resistance of the composite. SEM, EDAX, XRD and oxidation measurement techniques are used to study the oxidation behavior and to characterize the composite specimens. Oxidation of the composite material without protective coatings is seen to be very rapid during the initial stages of exposure to the high temperatures but subsequently slowed down due to the formation of a protective surface layer of oxide. The oxidation was especially severe above 600 K. The interface between the matrix and reinforcement particles and the grain boundary regions of intermetallic precipitates in the matrix enhance this oxidation process since they provided sites for oxidation initiation. Aluminum coating on the composite obtained by DC magnetron sputtering technique and AlCrN coating obtained by low voltage electron beam evaporation technique reduce the oxidation rate effectively since the interface regions between the matrix and reinforcement, grain boundary regions of the matrix are unexposed to the atmosphere. Aluminum coating provides better oxidation resistance for 6061 Al/SiC composites.

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Lei, Xuefeng, Jiangfeng Xiang, Xiaoling Ma, Chiwei Wang, and Jutang Sun. "Surface modification of aluminum with tin oxide coating." Journal of Power Sources 166, no. 2 (April 2007): 509–13. http://dx.doi.org/10.1016/j.jpowsour.2006.12.105.

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Lukauskaitė, Raimonda, Donatas Šiurkus, and Olegas Černašėjus. "RESEARCH ON THE PROPERTIES OF THERMAL SPRAYED NI-CR-SI-FE-B COATINGS / TERMINIU BŪDU UŽPURKŠTŲ NI-CR-SI-FE-B DANGŲ SAVYBIŲ TYRIMAS." Mokslas - Lietuvos ateitis 6, no. 4 (February 4, 2013): 604–7. http://dx.doi.org/10.3846/mla.2012.101.

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The article deals with the flame sprayed Ni-Cr-Si-Fe-B coating on aluminum alloy substrates. Before the thermal spraying process, aluminum samples were modified applying chemical, mechanical and thermal processing pre-treatment methods. The main aluminum surface treatment was removing an oxide layer from the surface and improving the exploitation properties of nickel-based coatings. The work involved coating microstructure, porosity, adhesion and microhardness tests. The dependence of the estimated exploitation properties of flame spray coatings on aluminum surface preparation methods and technological parameters of spraying has been established. Santrauka Straipsnyje nagrinėjamos liepsniniu būdu ant aliuminio lydinių substratų užpurkštos Ni-Cr-Si-Fe-B dangos. Aliuminio bandiniai prieš terminį purškimą buvo apdoroti cheminiais, mechaniniais ir terminiais būdais. Pagrindinis aliuminio paviršiaus apdorojimo tikslas buvo pašalinti oksidų sluoksnį nuo paviršiaus ir pagerinti nikelio pagrindo dangų eksploatacines savybes. Atlikti dangos mikrostruktūros, porėtumo, adhezijos ir mikrokietumo tyrimai. Nustatyta liepsninio purškimo būdu gautų dangų eksploatacinių savybių priklausomybė nuo aliuminio paviršiaus paruošimo būdų ir purškimo technologinių parametrų.

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Yang, H. S., D. H. Jang, and K. J. Lee. "Aluminum Oxide Formation On Fecral Catalyst Support By Electro-Chemical Coating." Archives of Metallurgy and Materials 60, no. 2 (June 1, 2015): 1503–6. http://dx.doi.org/10.1515/amm-2015-0161.

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Abstract FeCrAl is comprised essentially of Fe, Cr, Al and generally considered as metallic substrates for catalyst support because of its advantage in the high-temperature corrosion resistance, high mechanical strength, and ductility. Oxidation film and its adhesion on FeCrAl surface with aluminum are important for catalyst life. Therefore various appropriate surface treatments such as thermal oxidation, Sol, PVD, CVD has studied. In this research, PEO (plasma electrolytic oxidation) process was applied to form the aluminum oxide on FeCrAl surface, and the formed oxide particle according to process conditions such as electric energy and oxidation time were investigated. Microstructure and aluminum oxide particle on FeCrAl surface after PEO process was observed by FE-SEM and EDS with element mapping analysis. The study presents possibility of aluminum oxide formation by electro-chemical coating process without any pretreatment of FeCrAl.

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Surzhikov, А. P. "COMPOSITION AND STRUCTURE OF COMPOSITE COATINGS BASED ON METAL OXIDES AND POLYTETRAFLUOROETHYLENEDEPOSITED UNDER CONDITIONS OF ELECTRON-INITIATED ENDOTHERMIC PROCESSES." Eurasian Physical Technical Journal 17, no. 2 (December 24, 2020): 31–38. http://dx.doi.org/10.31489/2020no2/31-38.

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In this article features of physicochemical processes initiated by the low-energy electron flow between the components of the target based on nitrates of metals and metals, their influence on the kinetics of the formation of volatile products, the chemical composition and structure of the deposited coatings are established. When electrons act on a mixture of aluminum nitrate and dispersed aluminum, zinc oxide coatings containing zinc nanorods are formed. The impact of the electron flow on a mechanical mixture of powders of iron nitrate and dispersed aluminum is accompanied by explosive evaporation of the target, and a large number of microdroplet formations deposited at the final stage of exothermic reactions in the surface layers of the target are fixed on the surface of the coating containing oxides and metal nanoparticles. The features of the structure and chemical composition of coatings deposited from the volatile products of electron beam dispersion of a mechanical mixture of polytetrafluoroethylene, iron nitrate, and aluminum are determined. It is shown that under such conditions of generation of the gas phase, coatings are formed consisting of a polymer matrix and containing particles of oxide, a free metal, and a certain amount of the initial undecomposed salt. The result of exothermic reactions in the crucible is partial defluorination and increased defectiveness of the molecular structure of the fluoroplastic matrix.

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Sowa, Maciej, Marta Wala, Agata Blacha-Grzechnik, Artur Maciej, Alicja Kazek-Kęsik, Agnieszka Stolarczyk, and Wojciech Simka. "Corrosion Inhibitor-Modified Plasma Electrolytic Oxidation Coatings on 6061 Aluminum Alloy." Materials 14, no. 3 (January 29, 2021): 619. http://dx.doi.org/10.3390/ma14030619.

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There are many methods for incorporating organic corrosion inhibitors to oxide coatings formed on aluminum alloys. However, typically they require relatively concentrated solutions of inhibitors, possibly generating a problematic waste and/or are time-/energy-consuming (elevated temperature is usually needed). The authors propose a three-step method of oxide layer formation on 6061-T651 aluminum alloy (AAs) via alternating current (AC) plasma electrolytic oxidation (PEO), impregnation with an 8-hydroxyquinoline (8-HQ) solution, and final sealing by an additional direct current (DC) polarization in the original PEO electrolyte. The obtained coatings were characterized by scanning electron microscopy, roughness tests, contact angle measurements, X-ray diffraction, Raman spectroscopy, and X-ray photoelectron spectroscopy. Additionally, corrosion resistance was assessed by potentiodynamic polarization in a NaCl solution. Two types of the coating were formed (A—thicker, more porous at 440 mA cm−2; B—thinner, more compact at 220 mA cm−2) on the AA substrate. The 8-HQ impregnation was successful as evidenced by XPS. It increased the contact angle only for the B coatings and improved the corrosion resistance of both coating systems. Additional DC treatment destroyed superficially adsorbed 8-HQ. However, it served to block the coating pores (contact angle ≈ 80°) which improved the corrosion resistance of the coating systems. DC sealing alone did not bring about the same anti-corrosion properties as the combined 8-HQ impregnation and DC treatment which dispels the notion that the provision of the inhibitor was a needless step in the procedure. The proposed method of AA surface treatment suffered from unsatisfactory uniformity of the sealing for the thicker coatings, which needs to be amended in future efforts for optimization of the procedure.

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SHARIFI, HOSSEIN, MAHMOOD ALIOFKHAZRAEI, GHASEM BRATAI DARBAND, and SUMAN SHRESTHA. "A REVIEW ON ADHESION STRENGTH OF PEO COATINGS BY SCRATCH TEST METHOD." Surface Review and Letters 25, no. 03 (March 8, 2018): 1830004. http://dx.doi.org/10.1142/s0218625x18300046.

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Adhesion strength is one of the important properties that reflects the quality of a plasma electrolytic oxidation (PEO) coating. Scratch testing can be considered as an appropriate technique to evaluate the adhesion strength of PEO coatings on magnesium, titanium, and aluminum substrates. The scratch test is usually performed either under a constant or a progressively increasing normal load, where the critical load is used as a measure of adhesion strength of the coatings. In this review paper, the effect of different factors such as duration of coating processing, electrolyte composition, and processing current density, as well as different additives to the electrolyte bath, was studied on the adhesion strength of PEO coatings formed on magnesium, titanium, and aluminum substrates. It is understood that an optimum increase in process time and input energy leads to a corresponding increase in thickness of the PEO dense oxide layer and, consequently, an increase in critical load and adhesion strength. Moreover, the electrolyte composition and additives were found to affect the coating microstructure and composition and, subsequently, the coating adhesion strength.

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Maximov, M. Yu, A. A. Popovich, and A. M. Rumyantsev. "Influence of Passivation Coatings Synthesized by Atomic Layer Deposition on Li-Ion Batteries Cathode Cycle Life." Advanced Materials Research 1120-1121 (July 2015): 730–34. http://dx.doi.org/10.4028/www.scientific.net/amr.1120-1121.730.

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In this work, we investigated the influence of passivation coating of aluminum oxide on cycle life of lithium-ion batteries. Al2O3 was synthesized by atomic layer deposition directly on the porous electrodes based on LiCoO2. More than 800 charge-discharge cycles were done. No increase of internal resistance due to Al2O3 coating was observed. According to the results, electrodes coated by aluminum oxide have better cycle life.

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Vovk, S. Y., N. O. Ferents, and D. V. Kharyshyn. "RESEARCH ON THE EFFECT OF PROTECTING COATING ON THE FIRE RESISTANCE OF ALUMINUM ALLOY STRUCTURES." Fire Safety, no. 34 (July 19, 2019): 16–20. http://dx.doi.org/10.32447/20786662.34.2019.03.

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Polyfunctional protective coatings based on filled polysiloxane compositions are technological and can be used to increase the fire resistance of metal structural materials due to high thermomechanical properties, which are determined by stable structural and phase composition. The influence of protective coatings on the basis of polysiloxane-filled oxide components on fire resistance of aluminum alloys is investigated in the work. The choice of the initial compositions for fire protection coatings was carried out with the aim of obtaining of expanded heat-insulating heatresistant layer on the surface of an aluminum alloy at temperatures of 473 K and higher. The methods of physico-chemical analysis have established that when heated more than 473 K as a result of thermo oxidative degradation of polysiloxane with the release of gaseous products, there is an expanding coating with the formation of a fire-proof porous heat-insulating layer on the surface of an aluminum alloy. The coefficient of expanding the coating is within the range of 9.8 ... 12.4. The reliability of the use of physicochemical criteria when choosing the component composition of the coating and the effectiveness of the fire protection function is estimated from the results of the test on the aluminum alloy AMG6 and on the model of its thermal conductivity. 20 Пожежна безпека, №34, 2019 A model of thermal conductivity of a protective coating is proposed, which consists of a layer that limits heat transfer through a two-layer wall. When exposed to the aluminum plate of the heat flow, it is heated to the depth of the coating, which leads to its expanding and the formation of a thermal barrier. The dynamics of temperature distribution during a fire on the protective coating of an aluminum alloy is predicted by simulating the heat transfer process in a homogeneous solid by a mathematical model. The theoretical and practical researches have established the dependence of the parameter of heating the protected aluminum alloy to the critical temperature, depending on the thickness of the coating. The presence on the surface of a protected alloy coating, based on the filled polysiloxane, changes the process of heat transfer to its surface, which increases the fire resistance of the structure by 3 ...4 times.

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49

Berbel, Larissa Oliveira, Paulo Rogério Pinto Rodrigues, and Everson do Prado Banczek. "Aluminum Coating Obtained through the Sol-Gel Method to Protect Metallic Surfaces against Corrosion." Materials Science Forum 805 (September 2014): 190–95. http://dx.doi.org/10.4028/www.scientific.net/msf.805.190.

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Before metallic materials are painted, surface pre-treatments are usually applied, these are known as conversion treatments. Such treatments aim to slow the degradation of the organic coating/metallic substrate system in aggressive environments. Amongst the most effective conversion coatings for aluminum and its alloys, is the chromatization. However, the high toxicity of this process waste has led industry to ban the chromatization process from the market and seek new procedures to protect metallic surfaces which, at the same time, present lower toxicity and are efficient to protect against corrosion. This study aims to obtain a coating composed of aluminum oxide on the Al AA 3003 alloy, as a potential method to substitute the chromatization process. A study on the protection properties against corrosion of the base metal, coated with oxide, was developed. Open circuit potential tests, electrochemical impedance spectroscopy, and anodic potentiodynamic polarization curves were carried out in a Na2SO4 0,5 molL-1 solution and pH 4,0. The morphology characterization was performed employing the scanning electronic microscopy (SEM). Results indicated that the new coating presented better behavior than the chromatized samples, suggesting that the former can substitute the chrome coating.

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50

Weirauch, Douglas A., Willy M. Balaba, and Anthony J. Perrotta. "Kinetics of the reactive spreading of molten aluminum on ceramic surfaces." Journal of Materials Research 10, no. 3 (March 1995): 640–50. http://dx.doi.org/10.1557/jmr.1995.0640.

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The spreading kinetics of molten aluminum on ceramic surfaces bearing reactive coatings has been studied through the direct observation of sessile drops, either formed in situ or emplaced at temperature. Analysis of videotapes permitted the assessment of the rate of advance of rapidly spreading droplets. Experimental conditions in this study were chosen to avoid the severe retarding effect of the aluminum oxide film which is typically encountered in aluminum wetting experiments. A variety of reactive coating systems were examined (B, Cu, Ni, Ti, and Ti + B), and the effect of coating amount was assessed. Based upon the experiments of this study, the main effect of the coatings is to drive spreading due to strong exothermic interfacial reactions. The intensity of the interfacial reaction causes the change in free energy per unit area of interface to dominate the rate of movement of the triple line.

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Journal articles on the topic 'Aluminum oxide coating'

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