The Experts below are selected from a list of 14382 Experts worldwide ranked by ideXlab platform
Christian Coddet - One of the best experts on this subject based on the ideXlab platform.
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size distribution of particles from individual wires and the effects of nozzle geometry in twin wire arc spraying
Surface & Coatings Technology, 2005Co-Authors: Han Lin Liao, Y L Zhu, Rodolphe Bolot, Christian CoddetAbstract:Abstract By separating particles from the anode and the cathode wires, particle properties of individual electrodes of the arc spray process were investigated. Bimodal size distribution was observed for particles from each single wire. In addition, after atomisation and acceleration, average diameter difference between particles from the anode and cathode becomes quite small and the difference can be reduced by increasing atomising gas pressure and/or by using a closed nozzle system with a converging–diverging orifice (CD/CL). Microstructure analysis indicates that the CD/CL nozzle tends to produce coatings with finer microstructure, lower porosity and Higher Oxide content, while the open nozzle system leads to very coarse coating microstructure with Higher porosity but less Oxide content. CFD analysis of the gas dynamics was performed for different nozzles and led to numerical prediction of splat diameter distribution. Results show a smaller average splat diameter and a narrower splat diameter distribution for the CD/CL nozzle that is in close agreements with the microstructure analysis. It was found that a major disadvantage of the open nozzle system is its relatively longer distance between the wires interception point and the nozzle exit where the gas velocity attains its maximum value.
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correlations between operating conditions microstructure and mechanical properties of twin wire arc sprayed steel coatings
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2003Co-Authors: G Jandin, Han Lin Liao, Zhiqiang Feng, Christian CoddetAbstract:Abstract An experimental design matrix was set up in which carbon steel coatings were deposited with a twin wire arc spray gun (TAFA 9000™), using either compressed air or nitrogen as spraying gas. The coating's mechanical properties were studied. Some correlations were made between these properties, spraying conditions and the microstructure of the deposits. Young's modulus was estimated by the single beam method using finite element modeling. Results show that direct relationships do exist between spray conditions, Oxide content in the coating and microhardness. Young's modulus of the coatings depends on the lamella thickness and the Oxide content. When increasing the compressed air flow rate, Young's modulus increases at first because smaller particles and finer lamellae were made and it decreases later because of a Higher Oxide content. The increase of nitrogen flow rate lowers the Oxide content and increases Young's modulus.
Han Lin Liao - One of the best experts on this subject based on the ideXlab platform.
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size distribution of particles from individual wires and the effects of nozzle geometry in twin wire arc spraying
Surface & Coatings Technology, 2005Co-Authors: Han Lin Liao, Y L Zhu, Rodolphe Bolot, Christian CoddetAbstract:Abstract By separating particles from the anode and the cathode wires, particle properties of individual electrodes of the arc spray process were investigated. Bimodal size distribution was observed for particles from each single wire. In addition, after atomisation and acceleration, average diameter difference between particles from the anode and cathode becomes quite small and the difference can be reduced by increasing atomising gas pressure and/or by using a closed nozzle system with a converging–diverging orifice (CD/CL). Microstructure analysis indicates that the CD/CL nozzle tends to produce coatings with finer microstructure, lower porosity and Higher Oxide content, while the open nozzle system leads to very coarse coating microstructure with Higher porosity but less Oxide content. CFD analysis of the gas dynamics was performed for different nozzles and led to numerical prediction of splat diameter distribution. Results show a smaller average splat diameter and a narrower splat diameter distribution for the CD/CL nozzle that is in close agreements with the microstructure analysis. It was found that a major disadvantage of the open nozzle system is its relatively longer distance between the wires interception point and the nozzle exit where the gas velocity attains its maximum value.
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correlations between operating conditions microstructure and mechanical properties of twin wire arc sprayed steel coatings
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2003Co-Authors: G Jandin, Han Lin Liao, Zhiqiang Feng, Christian CoddetAbstract:Abstract An experimental design matrix was set up in which carbon steel coatings were deposited with a twin wire arc spray gun (TAFA 9000™), using either compressed air or nitrogen as spraying gas. The coating's mechanical properties were studied. Some correlations were made between these properties, spraying conditions and the microstructure of the deposits. Young's modulus was estimated by the single beam method using finite element modeling. Results show that direct relationships do exist between spray conditions, Oxide content in the coating and microhardness. Young's modulus of the coatings depends on the lamella thickness and the Oxide content. When increasing the compressed air flow rate, Young's modulus increases at first because smaller particles and finer lamellae were made and it decreases later because of a Higher Oxide content. The increase of nitrogen flow rate lowers the Oxide content and increases Young's modulus.
G Jandin - One of the best experts on this subject based on the ideXlab platform.
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correlations between operating conditions microstructure and mechanical properties of twin wire arc sprayed steel coatings
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2003Co-Authors: G Jandin, Han Lin Liao, Zhiqiang Feng, Christian CoddetAbstract:Abstract An experimental design matrix was set up in which carbon steel coatings were deposited with a twin wire arc spray gun (TAFA 9000™), using either compressed air or nitrogen as spraying gas. The coating's mechanical properties were studied. Some correlations were made between these properties, spraying conditions and the microstructure of the deposits. Young's modulus was estimated by the single beam method using finite element modeling. Results show that direct relationships do exist between spray conditions, Oxide content in the coating and microhardness. Young's modulus of the coatings depends on the lamella thickness and the Oxide content. When increasing the compressed air flow rate, Young's modulus increases at first because smaller particles and finer lamellae were made and it decreases later because of a Higher Oxide content. The increase of nitrogen flow rate lowers the Oxide content and increases Young's modulus.
A Manzorobledo - One of the best experts on this subject based on the ideXlab platform.
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formation of active chlorine species involving the Higher Oxide mox 1 on active ti ruo2 iro2 anodes a dems analysis
Journal of Electroanalytical Chemistry, 2020Co-Authors: Mayra Lunatrujillo, Ricardo E Palmagoyes, Jorge Vazquezarenas, A ManzorobledoAbstract:Abstract It is accepted that the mechanism of electro-generated active chlorine (i.e. chloride oxidation on DSAs) involves water oxidation and hydroxyl radical co-electrosorption to initially form HOClads on the anode surface in a single pathway, and subsequent production of Cl2 and OCl− ions. The present study comprehensively evaluates the chloride oxidation on Ti/RuO2-IrO2 in solutions containing different NaCl concentrations and pH values. Differential Electrochemical Mass Spectroscopy (DEMS) is used to account for the in-situ surface reactions simultaneously occurring during chloride and water oxidations. It is found that HOCl does not lead the chlorine mechanism since OCl⦁ is detected in considerably larger amounts under some experimental conditions, and its onset overpotential is ~150 mV more negative than HOCl appearance at 0.2 mol L−1 NaCl. Additionally, the mass signals of OCl⦁ and HOCl are virtually similar at pH = 2 and slightly different at pH = 10, where these species should not respectively exist according to thermodynamic information. Under this premise, an extension of the reaction mechanism is proposed to consider an independent pathway producing adsorbed hypochlorite radical (OCl•ads) for electro-generated active chlorine, which could be the preferential one since RuO2 and IrO2 belong to the category of “active” anodes towards the Oxygen Evolution Reaction (OER), thus allowing the formation of the so-called Higher Oxide MOx(⦁O)ads (chemisorbed oxygen). Although the mechanisms involving the productions of HOClads and OCl•ads can simultaneously occur on two type of non-identified active sites, promoting the generation of both MOx(⦁OH)ads and MOx(⦁O)ads species, both strongly depend on surface pH.
Zhiqiang Feng - One of the best experts on this subject based on the ideXlab platform.
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correlations between operating conditions microstructure and mechanical properties of twin wire arc sprayed steel coatings
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2003Co-Authors: G Jandin, Han Lin Liao, Zhiqiang Feng, Christian CoddetAbstract:Abstract An experimental design matrix was set up in which carbon steel coatings were deposited with a twin wire arc spray gun (TAFA 9000™), using either compressed air or nitrogen as spraying gas. The coating's mechanical properties were studied. Some correlations were made between these properties, spraying conditions and the microstructure of the deposits. Young's modulus was estimated by the single beam method using finite element modeling. Results show that direct relationships do exist between spray conditions, Oxide content in the coating and microhardness. Young's modulus of the coatings depends on the lamella thickness and the Oxide content. When increasing the compressed air flow rate, Young's modulus increases at first because smaller particles and finer lamellae were made and it decreases later because of a Higher Oxide content. The increase of nitrogen flow rate lowers the Oxide content and increases Young's modulus.