Effect of the catalyst concentration, the immersion time and the aging time on the morphology, composition and corrosion performance of TEOS-GPTMS sol-gel coatings deposited on the AZ31 magnesium alloy

Barrios, Carlos Andrés Hernández; Cuao, C.A.; Jaimes, Miguel; Coy, A.E.; Viejo, F.

doi:10.1016/j.surfcoat.2017.06.047

Cited by 39 publications

(24 citation statements)

References 34 publications

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“…In particular, the combination of several methods such as the Plasma Electrolytic Oxidation (PEO) and the sol-gel process are identified as potential alternatives 9,10 . In this case, the micro-porous oxide coating obtained by the PEO process can be further sealed by adding a hybrid inorganic-organic polymeric (Si-O-Si) sol-gel coating on top to provide an adequate corrosion protection on the metal surfaces [11][12][13][14][15] . Some researchers, as Tan et al 16 , Malayoglu et al 17 and Castellanos et al 18 , have addressed this strategy for the protection of Mg alloys, reporting an improvement of the corrosion resistance after a post-treatment including the deposition of a sol-gel coating.…”

Section: Introductionmentioning

confidence: 99%

Integrated corrosion‐resistant system for AZ31B Mg alloy via plasma electrolytic oxidation (PEO) and sol‐gel processes

Merino

Durán

Castro

2021

Int J of Appl Glass Sci

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In this work, an integrated system that combines anodizing process with the deposition of a hybrid SiO 2 sol-gel coating was developed with the aim of improving the corrosion resistance of AZ31B Mg alloy. The optimization of the anodizing conditions using an alkaline electrolyte (NaOH) modified with different concentrations of sodium metasilicate pentahydrate were explored together with the preparation and deposition of a SiO 2 sol obtained by hydrolysis and condensation of TEOS (tetraethoxysilane), GPTMS (3-Glycidyloxypropyl) trimethoxysilane), colloidal SiO 2 nanoparticles, and 1-Methylimidazole (MI). The surface morphology, coating thickness and composition were evaluated. The anodized coatings thickness was between 1.1 and 1.7 µm with composition corresponding to magnesium oxide and low silicon content. The corrosion performance was tested in 3.5% NaCl solution. The results revealed a good corrosion resistance behaviour after the anodizing of the Mg alloys. However, the best corrosion resistance was reached when the porous PEO layer was sealed with a hybrid silica sol-gel film. A decrease in the corrosion current density of three orders of magnitude is observed between Mg alloy (1.54E-06 A/cm 2 ) and multilayer system (2.80E-8 A/cm 2 ). Moreover, the polarization resistance for 8AF+SG samples showed a quite high value (31546.8 Ω cm 2 ) compared to Mg alloy (207.3 Ω cm 2 ).

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Section: Introductionmentioning

confidence: 99%

Integrated corrosion‐resistant system for AZ31B Mg alloy via plasma electrolytic oxidation (PEO) and sol‐gel processes

Merino

Durán

Castro

2021

Int J of Appl Glass Sci

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“…To compare the present results with the electrochemical properties of the same-classified AZ31 Mg alloys coated by other surface treatment methods, the electrochemical results via hydrothermal treatment, hydrophobic coating, superhydrophobic, hybrid coating, , sol–gel coating, metallic coating, anodizing coating, and PEO coating , are illustrated together in Figure . Several aspects from such comparison were drawn.…”

Section: Resultsmentioning

confidence: 99%

Electron-Donor and -Acceptor Agents Responsible for Surface Modification Optimizing Electrochemical Performance

Zoubi

Yang

2017

ACS Appl. Mater. Interfaces

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The electrochemical roles of electron-donor and -acceptor agents in surface reforming of magnesium alloy were investigated via plasma electrolysis. The surface modification was performed in an aluminate-based electrolyte, having urea and hydrazine with inherent molecular structures, which might act as electron acceptor and donor during plasma-assisted electrochemical reaction. The presence of hydrazine working as donor would promote the formation of magnesium aluminates in the oxide layer, resulting in superior compactness of the oxide layer to that when urea was used as the working as acceptor since the precipitation of MgCO was favored in the electrolyte with urea. The thickness of the oxide layer formed by a combination of urea and hydrazine was higher than urea, while the porosity was higher than hydrazine. The electrochemical performance was enhanced in the order of hydrazine, urea and hydrazine combined, and urea, which was discussed on the basis of impedance interpretation.

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“…Indeed, magnesium is not stable and spontaneously degrades during sol-gel deposition step when using acidic conditions. Hernández-Barrios et al [31] evaluated the corrosion behavior of AZ31 Mg alloy pretreated with a hybrid silica sol-gel coating prepared using acetic acid as acid-catalyst, and 3-glycidyloxypropyltrimethoxysilane (GPTMS) and TEOS as silica precursors. The results revealed that the sol synthesized with the highest acid concentration reached more stable gelation kinetics, but with the worst corrosion resistance performance (i corr : 1.3 × 10 −6 A/cm 2 ) compared with the sol synthesized with the slower acid concentration (i corr : 2.4 × 10 −7 A/cm 2 ).…”

Section: Passive Sol-gel Coating Barriermentioning

confidence: 99%

The Role of Silane Sol-Gel Coatings on the Corrosion Protection of Magnesium Alloys

Merino¹,

Durán²,

Castro³

2022

Current Trends in Magnesium (Mg) Research

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Magnesium alloys, as the lightest structural metallic material with promising physical, mechanical, and biodegradable properties, have become very attractive for different technical applications, especially for industrial and biomedical fields. However, rapid corrosion is the most critical obstacle that limits its use to play a major role in large-scale applications. The simplest way to control the corrosion rate is to prevent a direct contact of the magnesium substrate with the environment by using surface modification technologies. Silica sol-gel coatings are considered a promising solution to enhance the corrosion resistance of magnesium alloys because sol-gel-based coating systems form very stable chemical bonds with the metallic surface. In this chapter, an insight about the advances in silica sol-gel coatings as an alternative method to control the corrosion of Mg and its alloys will be exposed. A wide overview of the most relevant aspects and their current applications, specifically for aerospace, automobile, and biomedical applications will be described. The modification of silica sol-gel matrix by the incorporation of different types of inhibitors to achieve an active barrier property on Mg alloys has been also considered. Finally, the future perspective based on the development of new silica sol-gel coatings on Mg alloy will be presented.

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Effect of the catalyst concentration, the immersion time and the aging time on the morphology, composition and corrosion performance of TEOS-GPTMS sol-gel coatings deposited on the AZ31 magnesium alloy

Cited by 39 publications

References 34 publications

Integrated corrosion‐resistant system for AZ31B Mg alloy via plasma electrolytic oxidation (PEO) and sol‐gel processes

Integrated corrosion‐resistant system for AZ31B Mg alloy via plasma electrolytic oxidation (PEO) and sol‐gel processes

Electron-Donor and -Acceptor Agents Responsible for Surface Modification Optimizing Electrochemical Performance

The Role of Silane Sol-Gel Coatings on the Corrosion Protection of Magnesium Alloys

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