Improved corrosion resistance of AA2024 alloys through hybrid organic–inorganic sol–gel coatings produced from sols with controlled polymerisation

Rosero-Navarro, Nataly Carolina; Pellice, Sergio Antonio; Castro, Yolanda; Aparicio, Mario; Durán, Alicia

doi:10.1016/j.surfcoat.2009.01.019

Cited by 66 publications

(50 citation statements)

References 37 publications

(42 reference statements)

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“…These coatings are biocompatible, able to release Si compounds with osteoinductive properties, protecting the implant against corrosion, and enable the functionalization of the metal surface to achieve the desired cellular response to improve tissue regeneration [5][6][7][8][9].…”

Section: Introductionmentioning

confidence: 99%

Control of the degradation of silica sol-gel hybrid coatings for metal implants prepared by the triple combination of alkoxysilanes

Romero‐Gavilán

Barros-Silva

Garcı́a-Cañadas

et al. 2016

Journal of Non-Crystalline Solids

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Hybrid materials obtained by sol-gel process are able to degrade and release Si compounds that are useful in regenerative medicine due to their osteoinductive properties. The present work studies the behavior of new organic-inorganic sol-gel coatings based on triple mixtures of alkoxysilanes in different molar ratios.The precursors employed are methyl-trimethoxysilane (MTMOS), 3-glycidoxypropyl-trimethoxysilane (GPTMS) and tetraethyl-orthosilicate (TEOS). After optimization of the synthesis conditions, the coatings were characterized using 29 Si nuclear magnetic resonance ( 29 Si-MNR), Fourier transform infrared spectrometry (FT-IR), contact angle measurements, hydrolytic degradation assays, electrochemical impedance spectroscopy (EIS) and mechanical profilometry. The degradation and EIS results show that by controlling the amount of TEOS precursor in the coating it is possible to tune its degradation by hydrolysis, while keeping properties such as wettability at their optimum values for biomaterials application. The corrosion properties of the new coatings were also evaluated when applied to stainless steel substrate. The coatings showed an improvement of the anticorrosive properties of the steel which is important to protect the metal implants at the early stages of the regeneration process.

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Section: Introductionmentioning

confidence: 99%

Control of the degradation of silica sol-gel hybrid coatings for metal implants prepared by the triple combination of alkoxysilanes

Romero‐Gavilán

Barros-Silva

Garcı́a-Cañadas

et al. 2016

Journal of Non-Crystalline Solids

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“…on stainless steel 10,13 and aluminum based alloy, 14,16 these materials function as an anticorrosion barrier. Hybrid coatings could be further improved by incorporating nanosized particles such as SiO 2 , 14,15 aimed at increased density, hardness and/or scratch resistance.In hybrid systems, metal alkoxides are commonly used as precursors, in order to achieve strong covalent bonds between inorganic and organic phases. 12 In our previous work 17,18 coatings were synthesized from TEOS, MAPTMS and zirconium tetrapropoxide (ZTP) * Electrochemical Society Active Member.…”

mentioning

confidence: 99%

Corrosion Properties of UV Cured Hybrid Sol-Gel Coatings on AA7075-T6 Determined under Simulated Aircraft Conditions

Rodič

Milošev

2014

J. Electrochem. Soc.

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Novel hybrid sol-gel coatings have been developed for aluminum alloys as an alternative to the restricted use of chromate conversion coatings. They were prepared from two individual sols: zirconium tetrapropoxide (ZTP) and methacrylic acid (MAA) were added to siloxane sol prepared by mixing tetraethyl orthosilicate (TEOS) and organically modified silica 3-methacryloxypropyl trimethoxysilane (MAPTMS). The mixtures were deposited on alloy AA7075-T6 substrate and cured in air under daylight at room temperature or at 100 • C without the addition of photo-initiator. Different molar ratios of ZTP and MAA were investigated, as well as the effects of curing temperature and aging time. The corrosion behavior of the coated alloy was examined by electrochemical potentiodynamic measurements and six-month immersion tests in Harrison's solution, which simulates aircraft conditions. The coatings provided excellent corrosion protection in the atmospheric region and at high anodic potentials up to 7 V, as well as effective protection during long-term immersion. Curing under daylight improved the corrosion properties compared to curing in the dark. The corrosion behavior of synthesized coatings was compared to standard chromate coatings, including primer and topcoat. The morphology of the coatings was analyzed by scanning electron microscopy, and their adhesion to aluminum alloy surface measured using the X-cross cut test. Chromate conversion coatings (CCCs) have been used successfully for corrosion protection of aluminum alloys.1-3 The formation of CCCs involves the reduction of the oxy chromium species and consequent oxidation of aluminum. Stable, hydrophobic Cr(III) oxide/hydroxide film thus formed contains residual, releasable hexavalent chromium which maintains the active inhibition of the film. Due to rapid adsorption and passivation at the intermetallic sites, the main role of the inhibition process by Cr 6+ is to limit the oxygen reduction on intermetallics, which are the main initiation sites for localized corrosion of aluminum alloys.2,3 Further, the susceptibility to pit initiation is reduced, because the Cr 6+ compounds are adsorbed to aluminum oxide, minimizing the susceptibility to adsorption of chloride. Despite these excellent characteristics, the use of CCCs is restricted because of their hazards for the environment and humans. New alternatives include a broad spectrum of possibilities -from various cerium, molybdenum and organic inhibitors, barrier coatings including plasma deposited, sol-gel and electrodeposited coatings, to conducting polymers.3-6 An alternative yielding highly effective and long lasting protection that is fully comparable to CCCs is still to be found.Over the last decade, inorganic-organic (hybrid) sol-gel coatings have been studied as important alternatives to CCCs.7-13 They combine the properties of inorganic (scratch resistance, durability, adhesion, chemical and thermal stability) and organic (density, flexibility and functional capability) components. Of the one-component hybrid coatings...

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“…In the last decades, EIS has been widely used for coatings characterization [119,120,[193][194][195][196][197][198][199][200][201][202]. EIS is a transient technique where a sinusoidal signal (potential) is applied with low amplitude, to not disturb the equilibrium conditions of the system.…”

Section: Electrochemical Impedance Spectroscopy Methods (Eis)mentioning

confidence: 99%

Corrosion Protection Systems and Fatigue Corrosion in Offshore Wind Structures: Current Status and Future Perspectives

Price

Figueira

2017

Coatings

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Concerns over reducing CO 2 emissions associated with the burning of fossil fuels in combination with an increase in worldwide energy demands is leading to increased development of renewable energies such as wind. The installation of offshore wind power structures (OWS) is one of the most promising approaches for the production of renewable energy. However, corrosion and fatigue damage in marine and offshore environments are major causes of primary steel strength degradation in OWS. Corrosion can reduce the thickness of structural components which may lead towards fatigue crack initiation and buckling. These failure mechanisms affect tower service life and may result in catastrophic structural failure. Additionally, environmental pollution stemming from corrosion's by-products is possible. As a result, large financial investments are made yearly for both the prevention and recovery of these drawbacks. The corrosion rate of an OWS is dependent on different characteristics of attack which are influenced by access to oxygen and humidity. Structural degradation can occur due to chemical attack, abrasive action of waves, and microorganism attacks. Inspired by technological and scientific advances in recent years, the purpose of this paper is to discuss the current protective coating system technologies used to protect OWS as well as future perspectives.

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Improved corrosion resistance of AA2024 alloys through hybrid organic–inorganic sol–gel coatings produced from sols with controlled polymerisation

Cited by 66 publications

References 37 publications

Control of the degradation of silica sol-gel hybrid coatings for metal implants prepared by the triple combination of alkoxysilanes

Control of the degradation of silica sol-gel hybrid coatings for metal implants prepared by the triple combination of alkoxysilanes

Corrosion Properties of UV Cured Hybrid Sol-Gel Coatings on AA7075-T6 Determined under Simulated Aircraft Conditions

Corrosion Protection Systems and Fatigue Corrosion in Offshore Wind Structures: Current Status and Future Perspectives

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