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Ryosuke O. Suzuki - One of the best experts on this subject based on the ideXlab platform.
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Advanced hard anodic alumina coatings via etidronic acid Anodizing
Surface & Coatings Technology, 2017Co-Authors: Tatsuya Kikuchi, Shungo Natsui, Akimasa Takenaga, Ryosuke O. SuzukiAbstract:Abstract Advanced hard anodic alumina coatings measuring Hv = 610–769 on the Vickers hardness scale were obtained on an aluminum surface via aluminum Anodizing using a new electrolyte, etidronic acid. The ordered porous alumina was fabricated by two-step etidronic acid Anodizing at 260 V under self-ordering conditions, and pore-widening was carried out to control the porosity of the porous alumina. The Vickers hardness of the ordered porous alumina increased with decreasing diameter of the pores and porosity. Aluminum specimens were also anodized by the constant-current method under various concentrations, temperatures, and current densities. The Vickers hardness increased with decreasing concentration and temperature because chemical dissolution of the anodic oxide during Anodizing was suppressed. A hard porous alumina measuring Hv = 610 was obtained by Anodizing in a 0.05 M etidronic acid solution at 278 K and 5 Am − 2 . Subsequent thermal treatment caused the dehydration and corresponding hardening of the porous alumina, and a higher porous alumina hardness of Hv = 769 was successfully achieved by thermal treatment at 873 K for 12 h.
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Superhydrophilic and superhydrophobic aluminum alloys fabricated via pyrophosphoric acid Anodizing and fluorinated SAM modification
Journal of Alloys and Compounds, 2017Co-Authors: Ryunosuke Kondo, Daiki Nakajima, Shungo Natsui, Tatsuya Kikuchi, Ryosuke O. SuzukiAbstract:The fabrication of superhydrophilic and superhydrophobic aluminum alloys was achieved by pyrophosphoric acid Anodizing and SAM (self-assembled monolayer) modification. The Anodizing of three kinds of aluminum alloys, including 3004, 1N30, and 8021, in a concentrated pyrophosphoric acid solution resulted in the formation of numerous anodic alumina nanofibers. In addition, insoluble intermetallic compounds contained in the alloy matrix were exposed to the surface with increasing Anodizing time, and nanofiber-tangled intermetallic particles also formed on the surface during Anodizing. These anodized aluminum alloys exhibited a superhydrophilic behavior measuring less than 4° in the contact angle, and this superhydrophilicity was maintained via the long-term Anodizing process. The nanofiber-covered aluminum alloys were immersed in fluorinated phosphonic acid SAM/ethanol solutions, thereby modifying SAMs on the anodic alumina nanofibers. The contact angle of the SAM-modified aluminum alloys increased with the immersion time and temperature of the SAM solution, and the surface was drastically shifted to superhydrophobicity, measuring more than 150°, from superhydrophilicity. However, exceeding 10 min in the Anodizing process caused the contact angle to decrease and the gradual disappearance of hydrophobicity due to the formation of many hydrophilic intermetallic particles on the surface. The short-term pyrophosphoric acid Anodizing and subsequent SAM modification are useful for the formation of various superhydrophilic and superhydrophobic aluminum alloys.
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Self-ordered Porous Alumina Fabricated via Phosphonic Acid Anodizing
Electrochimica Acta, 2016Co-Authors: Shunta Akiya, Shungo Natsui, Tatsuya Kikuchi, Norihito Sakaguchi, Ryosuke O. SuzukiAbstract:Self-ordered periodic porous alumina with an undiscovered cell diameter was fabricated via electrochemical Anodizing in a new electrolyte, phosphonic acid (H3PO3). High-purity aluminum plates were anodized in phosphonic acid solution under various operating conditions of voltage, temperature, concentration, and Anodizing time. Phosphonic acid Anodizing at 150-180 V caused the self-ordering behavior of porous alumina, and an ideal honeycomb nanostructure measuring 370-440 nm in cell diameter was successfully fabricated on the aluminum substrate. Conversely, disordered porous alumina grew at below 140 V, and Anodizing at above 190 V caused local thickening due to oxide burning. Two-step phosphonic acid Anodizing allows the fabrication of high aspect ratio ordered porous alumina. HPO32-anions originated from the electrolyte were incorporated into the porous oxide during Anodizing. Consequently, a double-layered porous alumina consisting of a thick outer layer containing incorporated HPO32-anions, and a thin inner layer without anions was constructed via phosphonic acid Anodizing.
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fabrication of self ordered porous alumina via etidronic acid Anodizing and structural color generation from submicrometer scale dimple array
Electrochimica Acta, 2015Co-Authors: Tatsuya Kikuchi, Osamu Nishinaga, Shungo Natsui, Ryosuke O. SuzukiAbstract:Abstract Highly ordered anodic porous alumina with a large-scale cell diameter was successfully fabricated via Anodizing in a new electrolyte, etidronic acid (1-hydroxyethane-1,1-diphosphonic acid). High-purity aluminum specimens were anodized in a 0.3 M etidronic acid solution under constant current density and voltage conditions. Etidronic acid Anodizing at 210 to 270 V at the appropriate temperature caused the anodic porous alumina to exhibit self-ordering behavior, and periodic nanostructures measuring 530 to 670 nm in cell diameter were fabricated on the aluminum substrate. The self-ordering voltage and the corresponding cell diameter could be increased without burning by systematically increasing the stepwise voltage. Two-step etidronic acid Anodizing without nanoimprinting can easily yield the formation of highly ordered anodic porous alumina with a large-scale cell diameter. A submicrometer-scale dimple array fabricated via etidronic acid Anodizing and subsequent selective oxide dissolution gave rise to bright structural color with a rainbow distribution.
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Optimum Exploration for the Self-Ordering of Anodic Porous Alumina Formed via Selenic Acid Anodizing
Journal of The Electrochemical Society, 2015Co-Authors: Shunta Akiya, Shungo Natsui, Tatsuya Kikuchi, Ryosuke O. SuzukiAbstract:Improvements of the regularity of the arrangement of anodic porous alumina formed by selenic acid Anodizing were investigated under various operating conditions. The oxide burning voltage increased with the stirring rate of the selenic acid solution, and the high applied voltage without oxide burning was achieved by vigorously stirring the solution. The regularity of the porous alumina was improved as the Anodizing time and surface flatness increased. Conversely, the purity of the 99.5–99.9999 wt% aluminum specimens without second phases of metals and metallic compounds was not affected by the regularity of the porous alumina formed by selenic acid Anodizing. The porous alumina was also self-ordered on/around a defect, such as a grain boundary, under self-ordering high voltage Anodizing conditions. A highly ordered cell arrangement measuring 111 nm in diameter was successfully fabricated over the whole aluminum surface by selenic acid Anodizing using a 99.999 wt% aluminum plate at 273 K and 46 V for 24 h under vigorous stirring conditions
Tatsuya Kikuchi - One of the best experts on this subject based on the ideXlab platform.
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Advanced hard anodic alumina coatings via etidronic acid Anodizing
Surface & Coatings Technology, 2017Co-Authors: Tatsuya Kikuchi, Shungo Natsui, Akimasa Takenaga, Ryosuke O. SuzukiAbstract:Abstract Advanced hard anodic alumina coatings measuring Hv = 610–769 on the Vickers hardness scale were obtained on an aluminum surface via aluminum Anodizing using a new electrolyte, etidronic acid. The ordered porous alumina was fabricated by two-step etidronic acid Anodizing at 260 V under self-ordering conditions, and pore-widening was carried out to control the porosity of the porous alumina. The Vickers hardness of the ordered porous alumina increased with decreasing diameter of the pores and porosity. Aluminum specimens were also anodized by the constant-current method under various concentrations, temperatures, and current densities. The Vickers hardness increased with decreasing concentration and temperature because chemical dissolution of the anodic oxide during Anodizing was suppressed. A hard porous alumina measuring Hv = 610 was obtained by Anodizing in a 0.05 M etidronic acid solution at 278 K and 5 Am − 2 . Subsequent thermal treatment caused the dehydration and corresponding hardening of the porous alumina, and a higher porous alumina hardness of Hv = 769 was successfully achieved by thermal treatment at 873 K for 12 h.
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Superhydrophilic and superhydrophobic aluminum alloys fabricated via pyrophosphoric acid Anodizing and fluorinated SAM modification
Journal of Alloys and Compounds, 2017Co-Authors: Ryunosuke Kondo, Daiki Nakajima, Shungo Natsui, Tatsuya Kikuchi, Ryosuke O. SuzukiAbstract:The fabrication of superhydrophilic and superhydrophobic aluminum alloys was achieved by pyrophosphoric acid Anodizing and SAM (self-assembled monolayer) modification. The Anodizing of three kinds of aluminum alloys, including 3004, 1N30, and 8021, in a concentrated pyrophosphoric acid solution resulted in the formation of numerous anodic alumina nanofibers. In addition, insoluble intermetallic compounds contained in the alloy matrix were exposed to the surface with increasing Anodizing time, and nanofiber-tangled intermetallic particles also formed on the surface during Anodizing. These anodized aluminum alloys exhibited a superhydrophilic behavior measuring less than 4° in the contact angle, and this superhydrophilicity was maintained via the long-term Anodizing process. The nanofiber-covered aluminum alloys were immersed in fluorinated phosphonic acid SAM/ethanol solutions, thereby modifying SAMs on the anodic alumina nanofibers. The contact angle of the SAM-modified aluminum alloys increased with the immersion time and temperature of the SAM solution, and the surface was drastically shifted to superhydrophobicity, measuring more than 150°, from superhydrophilicity. However, exceeding 10 min in the Anodizing process caused the contact angle to decrease and the gradual disappearance of hydrophobicity due to the formation of many hydrophilic intermetallic particles on the surface. The short-term pyrophosphoric acid Anodizing and subsequent SAM modification are useful for the formation of various superhydrophilic and superhydrophobic aluminum alloys.
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Self-ordered Porous Alumina Fabricated via Phosphonic Acid Anodizing
Electrochimica Acta, 2016Co-Authors: Shunta Akiya, Shungo Natsui, Tatsuya Kikuchi, Norihito Sakaguchi, Ryosuke O. SuzukiAbstract:Self-ordered periodic porous alumina with an undiscovered cell diameter was fabricated via electrochemical Anodizing in a new electrolyte, phosphonic acid (H3PO3). High-purity aluminum plates were anodized in phosphonic acid solution under various operating conditions of voltage, temperature, concentration, and Anodizing time. Phosphonic acid Anodizing at 150-180 V caused the self-ordering behavior of porous alumina, and an ideal honeycomb nanostructure measuring 370-440 nm in cell diameter was successfully fabricated on the aluminum substrate. Conversely, disordered porous alumina grew at below 140 V, and Anodizing at above 190 V caused local thickening due to oxide burning. Two-step phosphonic acid Anodizing allows the fabrication of high aspect ratio ordered porous alumina. HPO32-anions originated from the electrolyte were incorporated into the porous oxide during Anodizing. Consequently, a double-layered porous alumina consisting of a thick outer layer containing incorporated HPO32-anions, and a thin inner layer without anions was constructed via phosphonic acid Anodizing.
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fabrication of self ordered porous alumina via etidronic acid Anodizing and structural color generation from submicrometer scale dimple array
Electrochimica Acta, 2015Co-Authors: Tatsuya Kikuchi, Osamu Nishinaga, Shungo Natsui, Ryosuke O. SuzukiAbstract:Abstract Highly ordered anodic porous alumina with a large-scale cell diameter was successfully fabricated via Anodizing in a new electrolyte, etidronic acid (1-hydroxyethane-1,1-diphosphonic acid). High-purity aluminum specimens were anodized in a 0.3 M etidronic acid solution under constant current density and voltage conditions. Etidronic acid Anodizing at 210 to 270 V at the appropriate temperature caused the anodic porous alumina to exhibit self-ordering behavior, and periodic nanostructures measuring 530 to 670 nm in cell diameter were fabricated on the aluminum substrate. The self-ordering voltage and the corresponding cell diameter could be increased without burning by systematically increasing the stepwise voltage. Two-step etidronic acid Anodizing without nanoimprinting can easily yield the formation of highly ordered anodic porous alumina with a large-scale cell diameter. A submicrometer-scale dimple array fabricated via etidronic acid Anodizing and subsequent selective oxide dissolution gave rise to bright structural color with a rainbow distribution.
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Optimum Exploration for the Self-Ordering of Anodic Porous Alumina Formed via Selenic Acid Anodizing
Journal of The Electrochemical Society, 2015Co-Authors: Shunta Akiya, Shungo Natsui, Tatsuya Kikuchi, Ryosuke O. SuzukiAbstract:Improvements of the regularity of the arrangement of anodic porous alumina formed by selenic acid Anodizing were investigated under various operating conditions. The oxide burning voltage increased with the stirring rate of the selenic acid solution, and the high applied voltage without oxide burning was achieved by vigorously stirring the solution. The regularity of the porous alumina was improved as the Anodizing time and surface flatness increased. Conversely, the purity of the 99.5–99.9999 wt% aluminum specimens without second phases of metals and metallic compounds was not affected by the regularity of the porous alumina formed by selenic acid Anodizing. The porous alumina was also self-ordered on/around a defect, such as a grain boundary, under self-ordering high voltage Anodizing conditions. A highly ordered cell arrangement measuring 111 nm in diameter was successfully fabricated over the whole aluminum surface by selenic acid Anodizing using a 99.999 wt% aluminum plate at 273 K and 46 V for 24 h under vigorous stirring conditions
Shungo Natsui - One of the best experts on this subject based on the ideXlab platform.
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Advanced hard anodic alumina coatings via etidronic acid Anodizing
Surface & Coatings Technology, 2017Co-Authors: Tatsuya Kikuchi, Shungo Natsui, Akimasa Takenaga, Ryosuke O. SuzukiAbstract:Abstract Advanced hard anodic alumina coatings measuring Hv = 610–769 on the Vickers hardness scale were obtained on an aluminum surface via aluminum Anodizing using a new electrolyte, etidronic acid. The ordered porous alumina was fabricated by two-step etidronic acid Anodizing at 260 V under self-ordering conditions, and pore-widening was carried out to control the porosity of the porous alumina. The Vickers hardness of the ordered porous alumina increased with decreasing diameter of the pores and porosity. Aluminum specimens were also anodized by the constant-current method under various concentrations, temperatures, and current densities. The Vickers hardness increased with decreasing concentration and temperature because chemical dissolution of the anodic oxide during Anodizing was suppressed. A hard porous alumina measuring Hv = 610 was obtained by Anodizing in a 0.05 M etidronic acid solution at 278 K and 5 Am − 2 . Subsequent thermal treatment caused the dehydration and corresponding hardening of the porous alumina, and a higher porous alumina hardness of Hv = 769 was successfully achieved by thermal treatment at 873 K for 12 h.
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Superhydrophilic and superhydrophobic aluminum alloys fabricated via pyrophosphoric acid Anodizing and fluorinated SAM modification
Journal of Alloys and Compounds, 2017Co-Authors: Ryunosuke Kondo, Daiki Nakajima, Shungo Natsui, Tatsuya Kikuchi, Ryosuke O. SuzukiAbstract:The fabrication of superhydrophilic and superhydrophobic aluminum alloys was achieved by pyrophosphoric acid Anodizing and SAM (self-assembled monolayer) modification. The Anodizing of three kinds of aluminum alloys, including 3004, 1N30, and 8021, in a concentrated pyrophosphoric acid solution resulted in the formation of numerous anodic alumina nanofibers. In addition, insoluble intermetallic compounds contained in the alloy matrix were exposed to the surface with increasing Anodizing time, and nanofiber-tangled intermetallic particles also formed on the surface during Anodizing. These anodized aluminum alloys exhibited a superhydrophilic behavior measuring less than 4° in the contact angle, and this superhydrophilicity was maintained via the long-term Anodizing process. The nanofiber-covered aluminum alloys were immersed in fluorinated phosphonic acid SAM/ethanol solutions, thereby modifying SAMs on the anodic alumina nanofibers. The contact angle of the SAM-modified aluminum alloys increased with the immersion time and temperature of the SAM solution, and the surface was drastically shifted to superhydrophobicity, measuring more than 150°, from superhydrophilicity. However, exceeding 10 min in the Anodizing process caused the contact angle to decrease and the gradual disappearance of hydrophobicity due to the formation of many hydrophilic intermetallic particles on the surface. The short-term pyrophosphoric acid Anodizing and subsequent SAM modification are useful for the formation of various superhydrophilic and superhydrophobic aluminum alloys.
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Self-ordered Porous Alumina Fabricated via Phosphonic Acid Anodizing
Electrochimica Acta, 2016Co-Authors: Shunta Akiya, Shungo Natsui, Tatsuya Kikuchi, Norihito Sakaguchi, Ryosuke O. SuzukiAbstract:Self-ordered periodic porous alumina with an undiscovered cell diameter was fabricated via electrochemical Anodizing in a new electrolyte, phosphonic acid (H3PO3). High-purity aluminum plates were anodized in phosphonic acid solution under various operating conditions of voltage, temperature, concentration, and Anodizing time. Phosphonic acid Anodizing at 150-180 V caused the self-ordering behavior of porous alumina, and an ideal honeycomb nanostructure measuring 370-440 nm in cell diameter was successfully fabricated on the aluminum substrate. Conversely, disordered porous alumina grew at below 140 V, and Anodizing at above 190 V caused local thickening due to oxide burning. Two-step phosphonic acid Anodizing allows the fabrication of high aspect ratio ordered porous alumina. HPO32-anions originated from the electrolyte were incorporated into the porous oxide during Anodizing. Consequently, a double-layered porous alumina consisting of a thick outer layer containing incorporated HPO32-anions, and a thin inner layer without anions was constructed via phosphonic acid Anodizing.
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fabrication of self ordered porous alumina via etidronic acid Anodizing and structural color generation from submicrometer scale dimple array
Electrochimica Acta, 2015Co-Authors: Tatsuya Kikuchi, Osamu Nishinaga, Shungo Natsui, Ryosuke O. SuzukiAbstract:Abstract Highly ordered anodic porous alumina with a large-scale cell diameter was successfully fabricated via Anodizing in a new electrolyte, etidronic acid (1-hydroxyethane-1,1-diphosphonic acid). High-purity aluminum specimens were anodized in a 0.3 M etidronic acid solution under constant current density and voltage conditions. Etidronic acid Anodizing at 210 to 270 V at the appropriate temperature caused the anodic porous alumina to exhibit self-ordering behavior, and periodic nanostructures measuring 530 to 670 nm in cell diameter were fabricated on the aluminum substrate. The self-ordering voltage and the corresponding cell diameter could be increased without burning by systematically increasing the stepwise voltage. Two-step etidronic acid Anodizing without nanoimprinting can easily yield the formation of highly ordered anodic porous alumina with a large-scale cell diameter. A submicrometer-scale dimple array fabricated via etidronic acid Anodizing and subsequent selective oxide dissolution gave rise to bright structural color with a rainbow distribution.
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Optimum Exploration for the Self-Ordering of Anodic Porous Alumina Formed via Selenic Acid Anodizing
Journal of The Electrochemical Society, 2015Co-Authors: Shunta Akiya, Shungo Natsui, Tatsuya Kikuchi, Ryosuke O. SuzukiAbstract:Improvements of the regularity of the arrangement of anodic porous alumina formed by selenic acid Anodizing were investigated under various operating conditions. The oxide burning voltage increased with the stirring rate of the selenic acid solution, and the high applied voltage without oxide burning was achieved by vigorously stirring the solution. The regularity of the porous alumina was improved as the Anodizing time and surface flatness increased. Conversely, the purity of the 99.5–99.9999 wt% aluminum specimens without second phases of metals and metallic compounds was not affected by the regularity of the porous alumina formed by selenic acid Anodizing. The porous alumina was also self-ordered on/around a defect, such as a grain boundary, under self-ordering high voltage Anodizing conditions. A highly ordered cell arrangement measuring 111 nm in diameter was successfully fabricated over the whole aluminum surface by selenic acid Anodizing using a 99.999 wt% aluminum plate at 273 K and 46 V for 24 h under vigorous stirring conditions
G.e. Thompson - One of the best experts on this subject based on the ideXlab platform.
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Features in aluminium alloy grains and their effects on Anodizing and corrosion
Surface and Coatings Technology, 2015Co-Authors: U. Donatus, D. Elabar, G.e. Thompson, T. Hashimoto, S. MorschAbstract:Distinct chemically and mechanically induced features, evident in the grains of the AA5083-O aluminium alloy, and their effects on Anodizing and corrosion have been studied. The grain distinct features are orientation dependent and are ridge-like. These features were found after Anodizing in Barker's reagent and after micro-trimming with a diamond knife (during the ultramicrotomy process). The grain features were also found to have a relationship with the anodic films formed on the alloy. Distinct striations (associated with the formation of the ridge-like features found after Anodizing) were observed on the surface of the alloy after the removal of the anodic layer (using a solution containing 20g Cr2O3+30ml HPO3 in 1l of deionised water at 60°C). Further etched regions, after the removal of the anodic layer, revealed subsurface micro-layers which appear to have significant influence on the corrosion, Anodizing and mechanical (at micro-scale) behaviour of the alloy.
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Optimization of Anodizing cycles for enhanced performance
Surface and Interface Analysis, 2013Co-Authors: M Curioni, T. Gionfini, A. Vicenzo, Peter Skeldon, G.e. ThompsonAbstract:Anodizing of aluminium alloys is often used to improve appearance, corrosion resistance or adhesion with organic coatings, with properties of the oxides tailored by controlling the Anodizing conditions. Some electrolytes can be used in relatively wide ranges of concentration, temperature and potential or current, while others display a narrower operational range. Optimization of the Anodizing process is a non-trivial task, involving the control of voltage and electrolyte nature, concentration and temperature. In this work, potentiodynamic Anodizing is proposed as a tool to characterize rapidly the behaviour of electrolyte/alloy combinations over a wide range of potential. It is shown that each electrolyte/alloy displays a fingerprint response, carrying information on the potential/current intervals suitable for porous oxide growth, on the oxidation behaviour of the second phase material on the alloy surface and on the maximum applicable potential or current. Copyright © 2013 John Wiley & Sons, Ltd.
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role of tartaric acid on the Anodizing and corrosion behavior of aa 2024 t3 aluminum alloy
Journal of The Electrochemical Society, 2009Co-Authors: Michele Curioni, Ekaterina Koroleva, G.e. Thompson, Peter Skeldon, J. FergusonAbstract:Tartaric acid is added to sulfuric acid Anodizing baths to generate porous anodic film that provides corrosion resistance to practical aerospace alloys and reduces the environmental impact of the traditional chromic acid Anodizing process. Here, a fundamental study on the effects of the addition of tartaric acid to the sulfuric acid Anodizing electrolyte has been undertaken. During Anodizing, it was evident that tartaric acid does not significantly affect the mechanism of porous film growth, but it reduces the growth rate of the porous anodic film. After Anodizing, in acidic environments, it may reduce the dissolution rate of a previously formed oxide. Furthermore, it was found that in a nearly neutral, chloride-rich environment, tartaric acid limits the anodic reaction of aluminum dissolution at concentrations in the hundreds of ppm range. The previous suggests that the good anticorrosion performance of alloys anodized in the presence of tartaric acid is due to residues of tartaric acid in the pore solution. © 2009 The Electrochemical Society.
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Anodizing of Aluminum under Nonsteady Conditions
Journal of The Electrochemical Society, 2009Co-Authors: M Curioni, Peter Skeldon, G.e. ThompsonAbstract:Porous anodic alumina is used in nanotechnology, electronics, and corrosion protection with the film morphology tuned by appropriate selection of Anodizing electrolyte and Anodizing voltage or current. Specifically, tailored potential-time or current-time regimes involving an initial voltage ramp may be used to modify the porous oxide morphology for improved corrosion resistance or nanotechnology applications. In this work, a fundamental study was performed on superpure aluminum to understand the processes of initiation and growth of the porous anodic oxide during Anodizing under potentiodynamic conditions. The current-potential response comprises an initial current plateau followed by a region of quasi-exponential dependence of current on applied potential. The first region was associated with initial thickening of the air-formed oxide, and the subsequent quasi-exponential region was related to the establishment of porous anodic film growth. Phenomena related to cell reorganization associated with the continuous variation in the Anodizing potential during the growth were examined by direct transmission electron microscopy of ultramicrotomed sections and stripped porous anodic films and compared with anodic oxides generated under steady potential conditions. © 2009 The Electrochemical Society.
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Role of Tartaric Acid on the Anodizing and Corrosion Behavior of AA 2024 T3 Aluminum Alloy
Journal of The Electrochemical Society, 2009Co-Authors: M Curioni, Ekaterina Koroleva, G.e. Thompson, Peter Skeldon, J. FergusonAbstract:Tartaric acid is added to sulfuric acid Anodizing baths to generate porous anodic film that provides corrosion resistance to practical aerospace alloys and reduces the environmental impact of the traditional chromic acid Anodizing process. Here, a fundamental study on the effects of the addition of tartaric acid to the sulfuric acid Anodizing electrolyte has been undertaken. During Anodizing, it was evident that tartaric acid does not significantly affect the mechanism of porous film growth, but it reduces the growth rate of the porous anodic film. After Anodizing, in acidic environments, it may reduce the dissolution rate of a previously formed oxide. Furthermore, it was found that in a nearly neutral, chloride-rich environment, tartaric acid limits the anodic reaction of aluminum dissolution at concentrations in the hundreds of ppm range. The previous suggests that the good anticorrosion performance of alloys anodized in the presence of tartaric acid is due to residues of tartaric acid in the pore solution.
Peter Skeldon - One of the best experts on this subject based on the ideXlab platform.
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Optimization of Anodizing cycles for enhanced performance
Surface and Interface Analysis, 2013Co-Authors: M Curioni, T. Gionfini, A. Vicenzo, Peter Skeldon, G.e. ThompsonAbstract:Anodizing of aluminium alloys is often used to improve appearance, corrosion resistance or adhesion with organic coatings, with properties of the oxides tailored by controlling the Anodizing conditions. Some electrolytes can be used in relatively wide ranges of concentration, temperature and potential or current, while others display a narrower operational range. Optimization of the Anodizing process is a non-trivial task, involving the control of voltage and electrolyte nature, concentration and temperature. In this work, potentiodynamic Anodizing is proposed as a tool to characterize rapidly the behaviour of electrolyte/alloy combinations over a wide range of potential. It is shown that each electrolyte/alloy displays a fingerprint response, carrying information on the potential/current intervals suitable for porous oxide growth, on the oxidation behaviour of the second phase material on the alloy surface and on the maximum applicable potential or current. Copyright © 2013 John Wiley & Sons, Ltd.
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role of tartaric acid on the Anodizing and corrosion behavior of aa 2024 t3 aluminum alloy
Journal of The Electrochemical Society, 2009Co-Authors: Michele Curioni, Ekaterina Koroleva, G.e. Thompson, Peter Skeldon, J. FergusonAbstract:Tartaric acid is added to sulfuric acid Anodizing baths to generate porous anodic film that provides corrosion resistance to practical aerospace alloys and reduces the environmental impact of the traditional chromic acid Anodizing process. Here, a fundamental study on the effects of the addition of tartaric acid to the sulfuric acid Anodizing electrolyte has been undertaken. During Anodizing, it was evident that tartaric acid does not significantly affect the mechanism of porous film growth, but it reduces the growth rate of the porous anodic film. After Anodizing, in acidic environments, it may reduce the dissolution rate of a previously formed oxide. Furthermore, it was found that in a nearly neutral, chloride-rich environment, tartaric acid limits the anodic reaction of aluminum dissolution at concentrations in the hundreds of ppm range. The previous suggests that the good anticorrosion performance of alloys anodized in the presence of tartaric acid is due to residues of tartaric acid in the pore solution. © 2009 The Electrochemical Society.
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Anodizing of Aluminum under Nonsteady Conditions
Journal of The Electrochemical Society, 2009Co-Authors: M Curioni, Peter Skeldon, G.e. ThompsonAbstract:Porous anodic alumina is used in nanotechnology, electronics, and corrosion protection with the film morphology tuned by appropriate selection of Anodizing electrolyte and Anodizing voltage or current. Specifically, tailored potential-time or current-time regimes involving an initial voltage ramp may be used to modify the porous oxide morphology for improved corrosion resistance or nanotechnology applications. In this work, a fundamental study was performed on superpure aluminum to understand the processes of initiation and growth of the porous anodic oxide during Anodizing under potentiodynamic conditions. The current-potential response comprises an initial current plateau followed by a region of quasi-exponential dependence of current on applied potential. The first region was associated with initial thickening of the air-formed oxide, and the subsequent quasi-exponential region was related to the establishment of porous anodic film growth. Phenomena related to cell reorganization associated with the continuous variation in the Anodizing potential during the growth were examined by direct transmission electron microscopy of ultramicrotomed sections and stripped porous anodic films and compared with anodic oxides generated under steady potential conditions. © 2009 The Electrochemical Society.
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Role of Tartaric Acid on the Anodizing and Corrosion Behavior of AA 2024 T3 Aluminum Alloy
Journal of The Electrochemical Society, 2009Co-Authors: M Curioni, Ekaterina Koroleva, G.e. Thompson, Peter Skeldon, J. FergusonAbstract:Tartaric acid is added to sulfuric acid Anodizing baths to generate porous anodic film that provides corrosion resistance to practical aerospace alloys and reduces the environmental impact of the traditional chromic acid Anodizing process. Here, a fundamental study on the effects of the addition of tartaric acid to the sulfuric acid Anodizing electrolyte has been undertaken. During Anodizing, it was evident that tartaric acid does not significantly affect the mechanism of porous film growth, but it reduces the growth rate of the porous anodic film. After Anodizing, in acidic environments, it may reduce the dissolution rate of a previously formed oxide. Furthermore, it was found that in a nearly neutral, chloride-rich environment, tartaric acid limits the anodic reaction of aluminum dissolution at concentrations in the hundreds of ppm range. The previous suggests that the good anticorrosion performance of alloys anodized in the presence of tartaric acid is due to residues of tartaric acid in the pore solution.
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destruction of coating material during spark Anodizing of titanium
Electrochimica Acta, 2006Co-Authors: Endzhe Matykina, G. Doucet, F. Monfort, A. Berkani, Peter Skeldon, G.e. ThompsonAbstract:An investigation has been carried out, using a sequential Anodizing procedure, of the loss of coating species to the electrolyte during spark Anodizing of titanium. Anodic coatings were formed galvanostatically in alkaline silicate electrolyte and then further thickened by re-Anodizing in alkaline phosphate electrolyte. In addition to examination of coating compositions and morphologies following different times of Anodizing in each electrolyte, solution analyses for silicon and titanium were carried out subsequent to Anodizing in the phosphate electrolyte. Significant amounts of both elements were detected, indicative of destruction of the coating at sites of dielectric breakdown in the phosphate electrolyte. The lost coating material is replaced by formation of phosphorus-rich material at the breakdown sites, as evident from elemental mapping of coatings.
