Journal articles: 'Aluminum oxide – Analysis'

1

Zudov, A. I. "Thermodepolarization Analysis of Aluminum — Anodic Aluminum Oxide Electret Systems." Russian Physics Journal 48, no. 8 (August 2005): 848–53. http://dx.doi.org/10.1007/s11182-005-0211-1.

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Jamaludin, Shamsul Baharin, Josef Hadipramana, Mohd Fitri Mohd Wahid, Kamarudin Hussin, and Azmi Rahmat. "Microstructure and Interface Analysis of Glass Particulate Reinforced Aluminum Matrix Composite." Advanced Materials Research 795 (September 2013): 578–81. http://dx.doi.org/10.4028/www.scientific.net/amr.795.578.

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A characterization of microstructure and interface was made on the composites Al-4 % Cu reinforced with 15 wt. % glass particulate. The composite was fabricated by powder metallurgy followed by solution treatment and artificial ageing. The microstructures of the composite showed that the glass particulates were in-homogenously distributed in the matrix and segregated near copper. The aluminum oxide layer was found between aluminum, copper and glass particulate. Micro cracks were observed in the aluminum oxide layer and at the interface between aluminum oxide layer and aluminum. Hardness increased as ageing time increased. Interface behavior and aging time influenced the hardness of the composite.

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Paparazzo, E. "XPS analysis of iron aluminum oxide systems." Applied Surface Science 25, no. 1-2 (February 1986): 1–12. http://dx.doi.org/10.1016/0169-4332(86)90021-8.

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4

Kurdi, B. N., and D. G. Hall. "Analysis of electromagnetic modes of aluminum–aluminum-oxide–gold tunnel junctions." Physical Review B 34, no. 6 (September 15, 1986): 3980–87. http://dx.doi.org/10.1103/physrevb.34.3980.

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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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Jung, Y. W., J. S. Byun, D. H. Woo, and Y. D. Kim. "Ellipsometric analysis of porous anodized aluminum oxide films." Thin Solid Films 517, no. 13 (May 2009): 3726–30. http://dx.doi.org/10.1016/j.tsf.2008.12.051.

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7

Kim, Mira, Yeongwoo Kim, Hakyoung Lee, Chan-Young Park, Won-Ki Lee, Taeho Kang, and Kwon Taek Lim. "Analysis of Polymer Hybrid-coated Anodic Aluminum Oxide." Molecular Crystals and Liquid Crystals 622, no. 1 (November 22, 2015): 120–24. http://dx.doi.org/10.1080/15421406.2015.1105037.

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8

Graham, Mike J. "Modern Analytical Techniques in High Temperature Oxidation and Corrosion." Materials Science Forum 522-523 (August 2006): 61–68. http://dx.doi.org/10.4028/www.scientific.net/msf.522-523.61.

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Modern analytical techniques are useful to characterize oxide films and to study oxide growth processes. This paper will summarize some of our work on the high temperature oxidation of both metals and semiconductors. Systems considered include binary III-V semiconductors, e.g. GaAs, which unlike silicon does not normally form high-quality native oxide. For GaAs, the influence of deuterium in the substrate and surface platinum have been evaluated with respect to oxide growth. Both aluminum-containing alloys (FeCrAl and NiAl) and semiconductors (AlGaAs, InAlAs and InAlP) are included. The objective is to produce good quality protective and insulating aluminum-containing oxides. In these studies, the application of several modern surface- analytical techniques, particularly Auger electron spectroscopy, X-ray photoelectron spectroscopy and secondary ion mass spectrometry, complemented by other techniques, e.g. transmission electron microscopy and X-ray analysis provides useful information on the chemical composition of the oxides and leads to a better understanding of oxidation and corrosion phenomena. In the case of AlGaAs and InAlP, thermal oxidation produces aluminum-containing oxides that have good insulating characteristics which makes the oxide films potentially useful for some device applications.

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Baca-Arroyo, Roberto. "Synthesis of an Aluminum Oxide-Based Functional Device Engineered by Corrosion/Oxidation Process." Crystals 10, no. 9 (August 21, 2020): 734. http://dx.doi.org/10.3390/cryst10090734.

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A disordered aluminum oxide grown on recycled aluminum sheets was synthesized by a corrosion/oxidation process. First, aluminum sheets recovered from unusable beverage cans were mechanically polished and dried in air atmosphere. Second, corrosion and oxidation into the aqueous solutions were the synthesis stages to produce aluminum oxide. Phase formation and electrical conduction of aluminum-oxide layers were validated by X-ray diffraction analysis and current–voltage plots at room temperature. An aluminum oxide-based structure operating under unusual principles at an extended lifetime resulted when an aluminum-oxide layer was inserted between two aluminum electrodes. This was attributed to an unusual electrical conduction. Some suggested models from the circuit theoretic properties are discussed here for potential usefulness for the aluminum oxide synthesized, as an environmental-friendly material that can be further useful into a sustainable scenario.

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Xamidov, Anvar, Farhodjon Hoshimov, Shavkat Mamatkulov, Khakimjan Butanov, Mirakhmat Yunusov, and Olim Ruzimuradov. "Catalytic Activity of Ni, Co, Mo Supported Anodic Aluminum Oxide Nanocomposites." Bulletin of Chemical Reaction Engineering & Catalysis 15, no. 3 (November 10, 2020): 845–52. http://dx.doi.org/10.9767/bcrec.15.3.8480.845-852.

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Nanostructured catalysts based on porous aluminum oxide (PAO) and some 3d metals, such as: nickel, cobalt, and molybdenum, have been obtained by anodic oxidation and impregnation. The synthesis of porous aluminum oxide with a highly ordered pore structure with pore sizes of 50 nm and a thickness of 50 µm is carried out by the method of two-stage anodic oxidation. The catalysts are obtained by impregnation of 3d metals into nanosized pores of aluminum oxide. The obtained catalysts based on nickel and porous Al2O3 are studied by scanning electron microscopy (SEM-EDX). The results of SEM-EDX analysis shows that a spongy structure with filament sizes of 100 nanometers containing particles of 3d metals formed on the surface of the aluminum oxide matrix. The results are presented on the activity of nickel and heterogenic cobalt and molybdenum nanoparticles in the reaction of hydrogenation of hexene to hexane. The results show that the yield temperature of the hexane is decreased and the yield of hexane is observed at 200 °C with Ni/Al2O3 catalysts, and a similar yield of hexane mass is achieved at temperatures higher than 250 °C with Co-Mo/Al2O3 and traditional nickel catalysts on kieselguhr. Copyright © 2020 BCREC Group. All rights reserved

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11

Li, Yang, Yu Lin Zheng, Zhuo Yi Lin, Zhi Liu Hu, and Jian Min Zeng. "Quantitative Analysis of Inclusions in Aluminum." Advanced Materials Research 476-478 (February 2012): 453–56. http://dx.doi.org/10.4028/www.scientific.net/amr.476-478.453.

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Three inclusion detection methods: image analysis, colorimetry and flux rinsing were compared aiming at the removal of solid oxide inclusions in molen aluminum in this paper. The testing results obtained from the comparative experiments indicate that the content of inclusions in aluminum can be detected quantitatively and quickly using the three methods. Image analysis is more intuitionistic, but testing value is a little larger; colorimetriy and flux rinsing method are of high accuracy, but testing values are estimated to be a little lower.

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12

Ju, Y., T. N. Farris, and S. Chandrasekar. "Theoretical Analysis of Heat Partition and Temperatures in Grinding." Journal of Tribology 120, no. 4 (October 1, 1998): 789–94. http://dx.doi.org/10.1115/1.2833780.

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A theoretical analysis is presented of heat partition and surface temperatures for the grinding of hardened steel with both aluminum oxide and CBN wheels. The numerical predictions of the model are shown to agree with experimental results available in the literature. It is found that heat partition varies over a wide range depending on grinding conditions. Also, heat partition is a strong function of position inside the grinding zone. The presence of the fluid inside the grinding zone can reduce the heat flux into the workpiece and the workpiece temperature significantly. For typical grinding of steel with CBN wheels, or creep feed grinding of steel with aluminum oxide or CBN wheels, it is possible to keep the fluid active and therefore to reduce thermal damage. However, the analysis suggests that the fluid may not be effective inside the grinding zone, in the conventional grinding of steel with aluminum oxide, due to boiling.

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13

Watanabe, Ryuzo, Duk Sun Choi, and Akira Kawasaki. "Gas Chromatographic Analysis of Degassing of Aluminum and Aluminum Alloy Powders." Materials Science Forum 534-536 (January 2007): 809–12. http://dx.doi.org/10.4028/www.scientific.net/msf.534-536.809.

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Gas release behavior from aluminum and Al 7075 alloy powders during heating in argon was investigated by in-situ gas chromatography. Water vapor, hydrogen, carbon mono-oxide were detected as individual evolution spectra against heating temperature and time. The mechanisms of water and hydrogen evolutions were studied in detail for the determination of effective degassing condition. The adsorbed water and aluminum hydrate on the particle surfaces were considered to be the sources for the released water. Hydrogen peaks were formed from released gases through the reaction of aluminum and magnesium with adsorbed and hydrated water, and from liberated hydrogen that would have been excessively occluded during atomization. For the alloy powder magnesium was found to lower the hydrogen evolution temperature to enhance overall hydrogen release.

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14

Ishii, Tadao. "Thermal characterization of iron oxide and aluminum oxide powders by emanation thermal analysis." Thermochimica Acta 93 (September 1985): 469–72. http://dx.doi.org/10.1016/0040-6031(85)85118-2.

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15

Bharadwaj, Gaurav. "Performance Analysis of FPSC using hybrid nanofluid of Aluminum oxide and Titanium oxide." IOP Conference Series: Materials Science and Engineering 1116, no. 1 (April 1, 2021): 012012. http://dx.doi.org/10.1088/1757-899x/1116/1/012012.

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16

Cai, L., and P. Sheng. "Analysis of Laser Evaporative and Fusion Cutting." Journal of Manufacturing Science and Engineering 118, no. 2 (May 1, 1996): 225–34. http://dx.doi.org/10.1115/1.2831015.

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This paper presents an analytical description of the evaporative and fusion laser cutting process. The model incorporates the effects of heat conduction, phase change, beam divergence, surface absorption and plasma absorption (for fusion cutting of metals) to estimate the geometry of the cutting front for given process parameters, material properties and workpiece geometry. Model estimates for kerf shape were developed for continuous-wave CO2 laser cutting of polymethyl-methacrylate (PMMA), aluminum oxide and 304 stainless steel. Comparison of model estimates with experimental results showed good agreement for cutting front geometries for PMMA, good kerf width agreement for aluminum oxide and model underestimation of kerf profile for 304 stainless steel. Results for the comparison of predicted and measured profile and centerline angles of inclination are also presented.

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17

Ma, Hongzhou, Zhixian Wang, Yaoning Wang, and Dingding Wang. "Phase transformation involved in the reduction process of magnesium oxide in calcined dolomite by ferrosilicon with additive of aluminum." Green Processing and Synthesis 9, no. 1 (February 11, 2020): 164–70. http://dx.doi.org/10.1515/gps-2020-0017.

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AbstractMetal magnesium is mainly produced from the calcined dolomite by the silicothermic production. However, in this process, the reduction temperature is higher while the reaction speed is slow, which results in higher energy consumption and serious environmental problems. In this paper, adding aluminum into the ferrosilicon reducing agent is expected to lower the reaction temperature so as to solve the problems above. The phase transition involved in the whole reduction process including with and without aluminum addition were investigated in details by theoretical calculation and experimental research. The influence of aluminum on the magnesium oxide reduction path was analysis to clarify the internal mechanism. The results show that aluminum added into the ferrosilicon would first react with magnesium oxide to form magnesium vapor and alumina under vacuum pressure of 10 Pa when the temperature rises to 720°C. Then, calcium aluminate would be formed by the reaction of aluminum oxide and calcium oxide. Once the temperature reaches 1150°C, silicon begins to reduce the magnesium oxide to create the silicon oxide that will finally react with calcium oxide to form calcium silicate. When the temperature rises above 1150°C, both the aluminum and silicon will participate in the reduction of magnesium oxide. In the process of heating up, the mixture of aluminum, ferrosilicon and calcined dolomite forms Mg2Al4Si5O18 and Ca3Al2(OH)12 phase with the components in calcined dolomite. Mg2Al4Si5O18 and Ca3Al2(OH)12 phase finally form Ca12Al14O33 phase. The interaction between aluminum and ferrosilicon in the mixture is less; the mixture of aluminum and ferrosilicon first forms Al3FeSi2 phase, and finally has the trend of forming Al4.5FeSi phase. There is a great difference between the phase transformation of aluminum in the mixture of aluminum, ferrosilicon and calcined dolomite and that of aluminum in the mixture of aluminum and ferrosilicon.

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18

Ivashutenko, Aleksander S., Nikita V. Martyushev, E. M. Vodopyanov, and Eugene P. Naiden. "The Analysis of Microstructure and the Properties of the Metallic-Matrix Composite on the Basis of the Copper and Aluminum Oxide." Applied Mechanics and Materials 770 (June 2015): 151–55. http://dx.doi.org/10.4028/www.scientific.net/amm.770.151.

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The article is devoted to the analysis of the possibilities to obtain gradient materials by the method of spark plasma sintering. Pure copper powders consisting of particles with the average particle size 100 microns and the nanodispersed powder of aluminum oxide were used in this study. Two powder compositions - pure copper powder and a mixture of copper powder and aluminum oxide powder were sintered:. As a result of the sintering process a sample with a double-area structure has been formed with a well-defined boundary between these areas. After sintering the copper powder porosity remained at the initial level. But having been mixed and sintered, the aluminum oxide powder particles agglomerated up to the average particle size of 80 – 100 microns.

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Ivashutenko, Aleksander S., Nikita V. Martyushev, E. M. Vodopyanov, and Valeriy P. Bezborodov. "The Analysis of Microstructure and the Properties of the Metallic-Matrix Composite on the Basis of the Copper and Aluminum Oxide." Applied Mechanics and Materials 770 (June 2015): 76–80. http://dx.doi.org/10.4028/www.scientific.net/amm.770.76.

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The article is devoted to the analysis of the possibilities to obtain gradient materials by the method of spark plasma sintering. Pure copper powders consisting of particles with the average particle size 100 microns and the nanodispersed powder of aluminum oxide were used in this study. Two powder compositions - pure copper powder and a mixture of copper powder and aluminum oxide powder were sintered:. As a result of the sintering process a sample with a double-area structure has been formed with a well-defined boundary between these areas. After sintering the copper powder porosity remained at the initial level. But having been mixed and sintered, the aluminum oxide powder particles agglomerated up to the average particle size of 80 – 100 microns.

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20

Thirumalaisamy, T. K., K. J. Lakshmi Sri, and R. Saravanan. "Local Structural Analysis of Al₂O₃, Cr:Al₂O₃ and V:Al₂O₃ Using Powder XRD." Materials Science Forum 671 (January 2011): 131–52. http://dx.doi.org/10.4028/www.scientific.net/msf.671.131.

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The electron density distribution and the local structure of aluminum oxide (Al2O3), chromium doped aluminum oxide (Cr:Al2O3) and vanadium doped aluminum oxide (V:Al2O3) have been studied. Powder X-ray data set of Al2O3 , Cr:Al2O3 and V:Al2O3 is analyzed in terms of cell parameters, thermal vibration parameters, 1D, 2D and 3 Dimensional electron density distributions. The bonding between the atoms using the maximum entropy method (MEM) and bond length distribution using pair distribution function (PDF) has been analyzed. The particle size of Al2O3 , Cr:Al2O3 and V:Al2O3 is also analyzed using XRD and SEM.

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21

Cofer, Wesley R., G. Garland Lala, and James P. Wightman. "Analysis of mid-tropospheric space shuttle exhausted aluminum oxide particles." Atmospheric Environment (1967) 21, no. 5 (January 1987): 1187–96. http://dx.doi.org/10.1016/0004-6981(87)90246-0.

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22

Nie, DengPan, Tao Xue, Yu Zhang, and XiangJun Li. "Synthesis and structure analysis of aluminum doped zinc oxide powders." Science in China Series B: Chemistry 51, no. 9 (August 14, 2008): 823–28. http://dx.doi.org/10.1007/s11426-008-0061-0.

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23

Grishankov, Alexey A., and Gulnara A. Voronova. "Analysis and processing of AFM images of anodic aluminum oxide." Vestnik Тomskogo gosudarstvennogo universiteta. Khimiya, no. 19 (September 1, 2020): 14–20. http://dx.doi.org/10.17223/24135542/19/2.

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24

Toh, S. K., D. G. McCulloch, J. Du Plessis, P. J. K. Paterson, A. E. Hughes, D. Jamieson, B. Rout, J. M. Long, and A. Stonham. "An Investigation of the Native Oxide of Aluminum Alloy 7475-T7651 Using XPS, AES, TEM, EELS, GDOES and RBS." Surface Review and Letters 10, no. 02n03 (April 2003): 365–71. http://dx.doi.org/10.1142/s0218625x0300530x.

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The native oxide on the rolled aerospace aluminum alloy 7475-T7651 was characterized using a variety of different techniques, including X-ray Photoelectron Spectrometry (XPS), Auger Electron Spectrometry (AES), Transmission Electron Microscopy (TEM), Electron Energy Loss Spectrometry (EELS), Glow Discharge Optical Emission Spectrometry (GDOES), and Rutherford Backscattered Spectrometry (RBS). All techniques revealed that the native oxide layer is magnesium-rich and is probably a mixture of magnesium and aluminum–magnesium oxides.1 The oxide layer was found to be of nonuniform thickness due to the rolling process involved during the manufacture of this sheet alloy; this complicates analysis using techniques which have poor spatial resolution. Direct thickness measurement from cross-sectional TEM reveals an oxide thickness which varies between 125 and 500 nm. This large variation in thickness was also evident from GDOES and AES depth profiles as well as the RBS data. Both XPS and RBS also show evidence for the presence of heavy metals in the oxide.

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Karakurkchi, Ann V., Nykolay D. Sakhnenko, Maryna V. Ved’, Ihor S. Luhovskyi, Hryhoriy A. Drobakha, and Maryna V. Mayba. "Features of Plasma Electrolytic Formation of Manganese- and Cobalt-Containing Composites on Aluminum Alloys." Advances in Materials Science and Engineering 2019 (August 7, 2019): 1–13. http://dx.doi.org/10.1155/2019/6381291.

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This paper presents the results of studies on the electrochemical treatment characteristics of aluminum and alloys in alkaline electrolytes. It is shown that the heterogeneity of the alloys composition complicates the formation of the surface oxide layer. To homogenize the treated surface and obtain oxide coatings doped with manganese and cobalt, electrolytes based on KOH and K4P2O7 with the addition of KMnO4 and CoSO4 were used. Plasma electrolytic oxidizing (PEO) in these electrolytes in the range of current densities 5–20 A/dm2 allows to obtain mixed oxide coatings which contained both aluminum oxide matrix and doping metal oxides Al2O3·MnOx and Al2O3·CoOy. It is shown that an increase in the PEO current density and the concentration of manganate- and cobalt(II) ions in the solution leads to an increase the content of dopant metals in the coatings outer layer. The incorporation of manganese and cobalt oxides in the composition of the surface layers was confirmed by the results of X-ray structural analysis. The rational modes of aluminum alloys PEO treatment were substantiated to obtain coatings with manganese and cobalt contents up to 25–40 аt.%. Formed oxide systems have a developed surface and high adhesion to the base metal and show an increased corrosion resistance and catalytic activity. This allows us to view them as promising materials for air- and water-cleaning technologies and internal combustion engine waste gas purification systems.

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Gleizes, Alain N., D. Samélor, Constantin Vahlas, Vincent Sarou-Kanian, Pierre Florian, and Dominique Massiot. "Temperature Dependent 4-, 5- and 6-Fold Coordination of Aluminum in MOCVD-Grown Amorphous Alumina Films: From Local Coordination to Material Properties." Advances in Science and Technology 91 (October 2014): 123–33. http://dx.doi.org/10.4028/www.scientific.net/ast.91.123.

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Aluminum 5-fold coordination coexisting with 4-and 6-fold coordination structurally characterizes amorphous aluminum oxide. For nearly 30 years now,27Al MAS NMR has enabled to detect and later on to quantify this feature thanks to advances in high-resolution instrumentation. The Introduction shortly reviews the results of investigations of 5-coordinate aluminum in amorphous alumina through NMR analysis. Aluminum oxide is not a glass-forming oxide. A convenient way to obtain the amorphous state is by thin film deposition. We present here27Al NMR analysis of a series of thin films of aluminum oxide prepared by metalorganic chemical vapor deposition (MOCVD) in the temperature range 360 ≤ Td≤ 720 °C. In this range, low Tdyield OH-containing films, while high Tdyield nanocrystallites-containing films. The variation of the[4]Al,[5]Al and[6]Al content with Tdis presented and discussed. It is correlated with the Tddependence of mechanical and corrosion protection properties. These properties are optimal when the structural disorder is to the utmost. Al coordination dependence on film thickness and the formation of metallic aluminum during the deposition process are also presented.

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Zhang, Xu Dong, Feng Gao, Xian Zheng Gong, Zhi Hong Wang, and Yu Liu. "Life Cycle Assessment of Erbium Oxide and Scandium Oxide." Materials Science Forum 944 (January 2019): 1130–36. http://dx.doi.org/10.4028/www.scientific.net/msf.944.1130.

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The demand for rare earths in aluminum alloy industry has experienced substantial growth in recent years. The erbium and scandium are two effective rare earth additives, mainly due to its remarkable improvement to aluminum alloy performance. However, the production process of rare earth has caused significant environmental problems. Hence, the analysis of environmental impacts associated with erbium and scandium processing is gaining importance. In this study, a life cycle analysis on the environment impacts of erbium oxide (Er2O3) and scandium oxide (Sc2O3) was carried out based on life cycle assessment (LCA) method. The life cycle assessment results showed that the production of 1 kg of Er2O3 and Sc2O3 generated 21.7 kg CO2 eq. and 743 kg CO2 eq., respectively. The leaching and purification process accounting for 95% of the overall water usage of Er2O3 production. For Sc2O3, energy and chemical consumption played a key role in reducing environmental impacts. Furthermore, Er2O3 appeared to have less environmental impact than Sc2O3 on most environmental issues. A detailed review of contribution was conducted and recommendations for further research were given.

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Qureshi, Muhammad I., Faheemuddin Patel, Nadhir Al-Baghli, Basim Abussaud, Bassam S. Tawabini, and Tahar Laoui. "A Comparative Study of Raw and Metal Oxide Impregnated Carbon Nanotubes for the Adsorption of Hexavalent Chromium from Aqueous Solution." Bioinorganic Chemistry and Applications 2017 (2017): 1–10. http://dx.doi.org/10.1155/2017/1624243.

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The present study reports the use of raw, iron oxide, and aluminum oxide impregnated carbon nanotubes (CNTs) for the adsorption of hexavalent chromium (Cr(VI)) ions from aqueous solution. The raw CNTs were impregnated with 1% and 10% loadings (weight %) of iron oxide and aluminum oxide nanoparticles using wet impregnation technique. The synthesized materials were characterized using scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). Batch adsorption experiments were performed to assess the removal efficiency of Cr(VI) ions from water and the effects of pH, contact time, adsorbent dosage, and initial concentration of the Cr(VI) ions were investigated. Results of the study revealed that impregnated CNTs achieved significant increase in the removal efficiency of Cr(VI) ions compared to raw CNTs. In fact, both CNTs impregnated with 10% loading of iron and aluminum oxides were able to remove up to 100% of Cr(VI) ions from aqueous solution. Isotherm studies were carried out using Langmuir and Freundlich isotherm models. Adsorption kinetics of Cr(VI) ions from water was found to be well described by the pseudo-second-order model. The results suggest that metallic oxide impregnated CNTs have very good potential application in the removal of Cr(VI) ions from water resulting in better environmental protection.

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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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Wang, Li Xian, Qiang Guo, Guo Liang Pan, and Chun Ying Guo. "Study on Coloring Protective Composite Oxide Film on Aluminum Surface." Advanced Materials Research 311-313 (August 2011): 1789–92. http://dx.doi.org/10.4028/www.scientific.net/amr.311-313.1789.

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This work presents a preparation of composite aluminum anodizing oxide film and its coloring process. When a kind of ultra fine silicon particle with negative charge was doped into the micropores of film by electrochemical method, the obtained composite film has bulk density of 3.53 g•cm-3, cavity ratio of 10.6 % and thickness of over 20 µm. Compared to traditional aluminum anodizing oxide films, the obtained new film gives higher hardness and mechanical properties. XRD analysis showed that silicon particles in composite oxide film were mainly composed of feldspar NaAlSi3O8. Furthermore, a kind of malonamide azo-colorant was introduced into the micropores of composite oxide film by in-situ synthesis to give various colors, where the malonyl group was as a bridge between aluminum oxide film and diazonium group. Properties evluation tests shows that the obtained colored decoration film exhibits high resistance to heat, salt-fog, mold and nature corrosion. Therefore, the composite aluminum anodizing oxide film is a promising candidate for application in stringent condition needing high protection as well as bright color.

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Thangthong, Jariyaporn, and Suksan Prombanpong. "An Analysis of Burn Defect in Hard Anodized Process of AL 3003." Advanced Materials Research 1119 (July 2015): 475–79. http://dx.doi.org/10.4028/www.scientific.net/amr.1119.475.

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The hard anodizing process is performed on aluminum 3003 work-part in order to increase surface hardness and corrosion resistant. Due to the fact that a massive of heat is generated during the process and attributing to burn defect. Burning can be described as an uneven growth and destruction of the oxide layer. The interface between the barrier layer and the aluminum is not smooth on a microscopic scale. Metallic aluminum extends as many small projections into the barrier layer. These intermetallic phases, metallic needles, and/or other impurities transport the electric current easier than the aluminum oxide and as a consequence give rise to a short circuit through the barrier layer in these pores. When the current density concentrates in these pores the temperature will rise at the bottom of the pores and cause burning defect to the work-part. Thus, an analysis of reducing burn defect is implemented using an experimental design technique. It is founded that with an increasing of ramp time, sulfuric acid concentration, and agitation in the hard anodizing process without relaxing current density, burn defects are substantially reduced.

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Rangel, Rodolfo Maia, Roberto José de Carvalho, and Maurício Leonardo Torem. "Organic matter removal from oil-water emulsions by electrocoagulation - 1: thermodynamic analysis." Rem: Revista Escola de Minas 66, no. 1 (March 2013): 77–83. http://dx.doi.org/10.1590/s0370-44672013000100010.

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A thermodynamic analysis of the organic matter (chemical oxygen demand - COD) removal from synthetic oil-water emulsions by the electrocoagulation process was performed with the objective of determining the most stable ionic species under diverse pH and aluminum concentration conditions and identifying possible removal mechanisms. The analysis suggests that the predominant species during the reactive stage are the amorphous aluminum hydroxide (for the mononuclear speciation of aluminum) and the positively charged trimeric species, Al3(OH)45+ (for the polynuclear speciation of aluminum). The emulsion destabilization probably occurs by charge neutralization, carried out jointly by the polynuclear species and by positively charged aluminum hydroxide. This sorption mechanism is likely to be the primary coagulation mechanism during the reactive stage. The formation of aluminum hydroxide and/or oxide during the stabilization stage may also take place, which indicates the gradual change of the dominant removal mechanism to sweep flocculation.

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Orme, Melissa, and Robert F. Smith. "Enhanced Aluminum Properties by Means of Precise Droplet Deposition." Journal of Manufacturing Science and Engineering 122, no. 3 (September 1, 1999): 484–93. http://dx.doi.org/10.1115/1.1285914.

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The use of molten aluminum droplets is investigated for potential application to precision droplet-based net-form manufacturing (PDM). In the proposed application, final structural components are made from the raw stock in one integrated operation by depositing molten metal droplets, layer after layer, via computer information. This work investigates the feasibility of the proposed technology by investigating the issues associated with generating molten aluminum droplets from capillary stream break-up, and examining the mechanical characteristics of the fabricated aluminum components. New results are presented which illustrate the generation of stable streams of molten aluminum droplets at rates of 24,000 droplets/second for a droplet stream speed of 10.9 m/s, corresponding to throughput rates of 2.3×10−4 kg/s (1.85 lb./hour). The droplets travel 2,500 droplet diameters in an inert environment before impingement with the substrate. Microstructural images are completely devoid of splat boundaries, which have been removed by remelting, and the grain size is approximately uniform throughout the field of view of the image that, in most cases presented, contains easily upwards of 30 splats. Also, it has been found that the presence of aluminum oxide in the melt does not influence the average grain size of the component. An oxide barrier however will encapsulate each grain if the oxides are not removed by filtration in the pre-jetting stage. The presence of aluminum oxide in the melt does not prohibit the removal of the splat boundaries. Mechanical analysis shows that fabrication with molten aluminum droplet deposition results in a 30 percent increase in ultimate tensile strength compared to the raw ingot stock. [S1087-1357(00)02402-3]

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Gertsman, Valéry Y., and Queenie S. M. Kwok. "TEM Investigation of Nanophase Aluminum Powder." Microscopy and Microanalysis 11, no. 5 (September 28, 2005): 410–20. http://dx.doi.org/10.1017/s1431927605050336.

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Nanophase aluminum powder was characterized in a field-emission-gun transmission electron microscope (TEM). Different techniques were used to investigate the structure of the particles, including conventional bright-field and dark-field imaging, scanning transmission electron microscopy (STEM), high-resolution lattice imaging, diffraction studies, energy dispersive X-ray spectroscopy (EDS) analysis and mapping, and electron energy loss spectroscopy (EELS) analysis and mapping. It has been established that the particle cores consist of aluminum single crystals that sometimes contain crystal lattice defects. The core is covered by a passivating layer of aluminum oxide a few nanometers thick. The alumina is mostly amorphous, but evidences of partial crystallinity of the oxide were also found. The thickness of this layer was measured using different techniques, and the results are in good agreement with each other. The particles are agglomerated in two distinct ways. Some particles were apparently bonded together during processing before oxidation. These mostly form dumbbells covered by a joint oxide layer. Also, oxidized particles are loosely assembled into relatively large clusters.

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Deyab, M. A., S. S. Abd El-Rehim, A. Abd El Moneim, and H. H. Hassan. "Improved Corrosion Resistance of Aluminum in 0.5 M HCl Solution using Plasma Electrolytic Oxidation." Zeitschrift für Physikalische Chemie 233, no. 5 (May 27, 2019): 609–25. http://dx.doi.org/10.1515/zpch-2018-1246.

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Abstract In this paper, the plasma electrolytic oxidation (PEO) was used to improve the corrosion resistance of aluminum in 0.5 M HCl solution. Influence of many factors such as the composition of electrolytes, time and inorganic additives on the performance of PEO process have been investigated. The surface morphology of PEO films was inspected using SEM, EDX and XRD analysis. The electrochemical impedance spectroscopy (EIS) and polarization measurements were carried out to evaluate the corrosion resistance of aluminum. The hardness and reduced modulus of aluminum surface at different PEO process time were determined by nanoindenter measurements. The results showed that the best conditions for formation high efficient oxide layer on the aluminum surface during PEO process were carried out in 0.001 M NaOH electrolyte containing 9 × 10−5 M Na2WO4 for 5 min. The PEO process is able to inhibit uniform and pitting corrosion of aluminum in HCl solution. The surface morphology analysis showed that PEO process produce a highly resistant protective oxide layer, mainly composed of orthorhombic crystalline phase of α-Al2O3. This oxide characterized by its greater hardness.

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Iwanciw, J., D. Podorska, and J. Wypartowicz. "Simulation of Oxygen and Nitrogen Removal from Steel by Means of Titanium and Aluminum." Archives of Metallurgy and Materials 56, no. 3 (September 1, 2011): 635–44. http://dx.doi.org/10.2478/v10172-011-0069-x.

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Simulation of Oxygen and Nitrogen Removal from Steel by Means of Titanium and Aluminum Authors' computer program was employed in the simulation of the course of steel refining by means of simultaneously used aluminium and titanium. The mass and chemical composition of liquid steel and non-metallic precipitates, were calculated at constant or variable temperature. The influence of assumed nitrides form on the results of simulation was determined. Nitrides may be considered either as separate phases or as the components of non-metallic solution. The stoichiometry of titanium oxide obtained also influences the results of simulation. Parallel analysis of steel refining was carried out with the use of FactSage program. As a result of calculations the subsequent states of equilibrium between steel and non-metallic phase were determined. It was found that aluminium and titanium nitrides may exist only as the components of oxide-nitride solution, not as separate phases.

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Dill, K. M., R. A. Reed, V. S. Calia, and R. J. Schulz. "Analysis of crystalline phase aluminum oxide particles from solid propellant exhausts." Journal of Propulsion and Power 6, no. 5 (September 1990): 668–71. http://dx.doi.org/10.2514/3.23269.

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Oshida, Yoshiki, Carlos A. Munoz, Mark M. Winkler, Azza Hashem, and Michio Itoh. "Fractal Dimension Analysis of Aluminum Oxide Particle for Sandblasting Dental Use." Bio-Medical Materials and Engineering 3, no. 3 (1993): 117–26. http://dx.doi.org/10.3233/bme-1993-3301.

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Mustafa, Ghazala, Katsumi Sakata, and Setsuko Komatsu. "Proteomic analysis of flooded soybean root exposed to aluminum oxide nanoparticles." Journal of Proteomics 128 (October 2015): 280–97. http://dx.doi.org/10.1016/j.jprot.2015.08.010.

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Załęska-Radziwiłł, Monika, and Nina Doskocz. "DNA changes inPseudomonas putidainduced by aluminum oxide nanoparticles using RAPD analysis." Desalination and Water Treatment 57, no. 3 (January 12, 2015): 1573–81. http://dx.doi.org/10.1080/19443994.2014.996015.

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Roeper, D. F., W. E. O'Grady, and P. M. Natishan. "Modeling the Chloride Ion Attack of Aluminum Oxide by XANES Analysis." ECS Transactions 58, no. 41 (April 24, 2014): 85–91. http://dx.doi.org/10.1149/05841.0085ecst.

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Thapa, Ram, Steven French, Carlos T. Ramos, Jose J. Gutierrez, Mircea Chipara, and Karen Lozano. "Electrorheological Analysis of Colloidal Dispersions of Aluminum Oxide and Silicone Oil." Journal of Nanoscience and Nanotechnology 11, no. 8 (August 1, 2011): 6852–57. http://dx.doi.org/10.1166/jnn.2011.4238.

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Evdokimov, I. I., and V. G. Pimenov. "ICP-AES analysis of aluminum isopropoxide, yttrium, and neodymium oxide nanopowders." Journal of Structural Chemistry 51, S1 (December 2010): 197–202. http://dx.doi.org/10.1007/s10947-010-0213-x.

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Wu, Yanpeng, and Chaoying Zhang. "Analysis of anti-condensation mechanism on superhydrophobic anodic aluminum oxide surface." Applied Thermal Engineering 58, no. 1-2 (September 2013): 664–69. http://dx.doi.org/10.1016/j.applthermaleng.2013.01.048.

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Salam, M. Abdus, and Suriati Sufian. "Hydrogen Adsorption Capacity Investigation of Ni-Co-Al Mixed Oxides." Advanced Materials Research 917 (June 2014): 360–64. http://dx.doi.org/10.4028/www.scientific.net/amr.917.360.

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Micro-mesoporous mixed oxides containing nickel, cobalt and aluminum have been synthesized using conventional coprecipitation method. FESEM and HRTEM analyses demonstrated the flower and hexagonal plate-like nanostructured of mixed oxides. Different mixed oxide formation, homogenous metal dispersion, textural properties were investigated using XRD, ICP-MS and BET (N2 adsorption-desorption) techniques. nanostructured mixed oxides exhibited 2.6 wt% hydrogen adsorption that were studied using temperature programmed reduction-adsorption-desorption (H2-TPR/TPD) and thermogravimetric and differential thermal analysis (TGA-DTA) techniques. Investigation corresponds that morphologies, textural properties and surface energy of mixed oxides are important in hydrogen adsorption.

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Korzekwa, Joanna, Michał Fal, and Aneta Gądek-Moszczak. "DOE Application for Analysis of Tribological Properties of the Al2O3/IF-WS2 Surface Layers." Open Engineering 11, no. 1 (December 20, 2020): 171–81. http://dx.doi.org/10.1515/eng-2021-0012.

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AbstractThe article presents the effect of the processing parameters on tribological properties of aluminum oxide coatings Al2O3 doped with fullerene-like tungsten disulfide (IF-WS2) by design of experiment (DOE). Anodic oxidation of aluminum alloy was carried out in a ternary solution of SAS (sulfuric, adipic and oxalic acids) with IF-WS2. The thickness, geometric structure of the surface (SGP) and the tribological properties such as friction coefficient of tribological pair: Al2O3/IF-WS2 with polieteroeteroketon filled with graphite, carbon fiber and PTFE (named PEEK/BG) were investigated. The influence of electrolysis time and temperature on the tribological properties of coatings was studied using 2k factorial design. The stabilization of the friction coefficient indicates generation of steady anti-wear and anti-seizure Al2O3/IF-WS2 oxide coatings. DOE suggest i.e. high positive correlation between oxide thickness and time and temperature of the anodizing process.

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Maleki, Ali, Behzad Niroumand, and Mahmood Meratian. "Effects of processing temperature on in-situ reinforcement formation in Al(Zn)/Al2O3(ZnO) nanocomposite." Metallurgical and Materials Engineering 21, no. 4 (December 31, 2015): 283–91. http://dx.doi.org/10.30544/75.

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The aim of present work was to investigate effects of processing temperature on the microstructure of in-situ processed aluminum/alumina composites. A new activated powder injection (API) method was used to synthesize the aluminum matrix composites by displacement reaction between aluminum and zinc oxide. A mechanically activated mixture of aluminum and zinc oxide powder was injected into a vortex of molten aluminum. Three melting temperatures of 680, 730 and 790 °C were selected as the processing temperatures. The composite slurries were solidified under a pressure of 200 MPa. Microstructures of the samples were studied using electron microscopy and image analysis techniques. Refinement of in-situ reinforcements with increasing processing temperature was observed and rationalized.

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Grachev, V. A., and N. D. Turakhodjaev. "Influence of High-Temperature Treatment of Melt on the Composition and Structure of Aluminum Alloy." Archives of Foundry Engineering 17, no. 4 (December 20, 2017): 61–66. http://dx.doi.org/10.1515/afe-2017-0131.

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Abstract The aim of the current study was to examine the structure of an alloy treated at various temperatures up to 2,000-2,100 °C. Among research techniques for studying alloy structure there were the electron and optical microstructure, X-ray structure, and spectral analysis, and for studying the developed furnace geometric parameters the authors employed mathematical modeling method. The research was performed using aluminum smelting gas-fired furnaces and electric arc furnaces. The objects of the study were aluminum alloys of the brand AK7p and AK6, as well as hydrogen and aluminum oxide in the melt. For determining the hydrogen content in the aluminum alloy, the vacuum extraction method was selected. Authors have established that treatment of molten aluminum alloy in contact with carbon melt at high temperatures of 2,000-2,100 °C has resulted in facilitating reduction of hydrogen and aluminum oxide content in the melt by 40- 43% and 50-58%, respectively, which is important because hydrogen and aluminum oxide adversely affect the structure and properties of the alloy. Such treatment contributes to the formation of the extremely fine-grained microstructure of aluminum alloy.

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Скрябин, Максим, and Maxim Skryabin. "Steady oxide film obtaining on surface of piston aluminum alloys at micro-arc oxidation." Science intensive technologies in mechanical engineering 2018, no. 5 (April 19, 2018): 19–26. http://dx.doi.org/10.12737/article_5ad8d290551210.41386001.

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The formation of thin oxide films on piston aluminum alloys through the method of micro-arc oxidation is considered. The mechanism of the formation crystal inclusions and high-temperature structures depending on ion current density in time is described. One of the methods of surface strengthening piston aluminum alloys – micro-arc oxidation is described and analyzed. The mechanisms of oxide layers formation taking into account the impact of alloy elements of piston aluminum alloys are considered. The analysis of porous cells is carried out, basic properties of coatings are investigated.

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de Oliveira, Amanda Sayure Kasuya, Adriana Perpetua Figueiredo Paulista, Ana Ellen Valentim de Alencar, and Tiago Pinheiro Braga. "Gelatin Template Synthesis of Aluminum Oxide and/or Silicon Oxide Containing Micro/Mesopores Using the Proteic Sol-Gel Method." Journal of Nanomaterials 2017 (2017): 1–11. http://dx.doi.org/10.1155/2017/2504796.

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Aluminum oxide and/or silicon oxide-based supports were synthesized by proteic sol-gel method. The characterization was performed through the analysis of TG, XRD, FTIR, SEM, and N2 physisorption. The XRD diffractograms showed an amorphous material profile. TG results indicate the total liberation of the organic and inorganic material in the calcination temperature used, occurring in different mass loss range. This piece of information was reaffirmed by the FTIR spectra, which presented characteristic bands of gelatin structure before calcinations which disappear in the spectrum of the solid after calcinations, indicating the loss of organic matter from gelatin after heat treatment. The spectra exhibited M-O stretching vibration at low wavenumbers after calcinations related to metal oxides. The acquired images by SEM suggest the obtaining of a highly porous material with very different characteristics depending on the composition of the support. The N2 isotherms indicate the presence of a micro/mesoporous oxide with interesting textural properties, particularly for the supports containing aluminum and silicon oxide. The ethanol dehydration results showed greater selectivity to diethyl ether compared to ethylene. From the reaction data, the following order of acid strength was obtained: 2Si-Al > Si-2Al > Si-Al > Al, which is related to the Si-Al ratio.

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Journal articles on the topic 'Aluminum oxide – Analysis'

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