Study on Surface Modification of Aluminum Alloys by Silicate-Based Hybrid Coating

Silicate-based hybrid coatings were deposited on aluminum alloy substrates following the methodology of sol-gel procedure and are applying to survey the corrosion protective behavior. The results show that the optimal intact and uniform film can be obtained by preparing with Si:Al mole ratio 48:1 and tempering at 140°C. It was noted that this modified hybrid coating reduced the corrosion current density from 1.532×10-4A/cm2 (bare substrate) to 2.782×10-8 A/cm2 in 3.5 wt. % NaCl solution. The coating represents an excellent stability, especially at higher temperature, therefore could offer a significant protection to 2024 aluminum alloy substrates.

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Evaluate Mechanical Behavior of Alumina Coated Aluminum Alloy Using Slow Strain Rates Test in 3.5% of NaCl Solution

Materials Science Forum ◽

10.4028/www.scientific.net/msf.969.242 ◽

2019 ◽

Vol 969 ◽

pp. 242-246

Author(s):

Dalip Singh ◽

Veena Dhayal ◽

D.C. Agarwal

Keyword(s):

Aluminum Alloy ◽

Sol Gel ◽

Dip Coating ◽

Coated Sample ◽

Slow Strain Rate Test ◽

Protective Behavior ◽

Nacl Solution ◽

Alumina Coatings ◽

Coating Methods ◽

Rate Test

This work is concerned with the investigation of the capability of alumina coatings, deposited over aluminum alloy by dip coating methods to improve mechanical properties. Alumina coatings were deposited using oxime-modified aluminum (III) isopropoxide as a sol-gel precursor. The Scanning electron microscopy (SEM-EDX) images of the coated samples suggest deposition of uniform and crack free alumina coatings. The mechanical property of the bare, and dip coated aluminum alloy were investigated by the slow strain rate test in 3.5% of NaCl solution. The coated sample indicate higher ultimate tensile strength, it’s reflect the protective behavior of coating.

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Corrosion Studies and Interfacial Bonding of Urea/Poly(dimethylsiloxane) Sol/Gel Hydrophobic Coatings on AA 2024 Aluminum Alloy

Langmuir ◽

10.1021/la062976g ◽

2007 ◽

Vol 23 (10) ◽

pp. 5505-5514 ◽

Cited By ~ 43

Author(s):

Mojca Fir ◽

Boris Orel ◽

Angela Šurca Vuk ◽

Aljaž Vilčnik ◽

Robi Ješe ◽

...

Keyword(s):

Aluminum Alloy ◽

Sol Gel ◽

Interfacial Bonding ◽

2024 Aluminum Alloy ◽

Hydrophobic Coatings ◽

Corrosion Studies ◽

Aa 2024

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Evaluation of Corrosion Resistance in 3.5% NaCl Solution of Hybrid Coatings Obtained from Plastics Materials

Materiale Plastice ◽

10.37358/mp.21.1.5459 ◽

2021 ◽

Vol 58 (1) ◽

pp. 201-209

Author(s):

Alina Crina Muresan ◽

Daniela Laura Buruiana ◽

Gabriel Bogdan Carp ◽

Sorin Berbece ◽

Constantin Trus

Keyword(s):

Corrosion Resistance ◽

Corrosion Rate ◽

Disperse Phase ◽

Phenol Formaldehyde ◽

Corrosion Current ◽

Phenol Formaldehyde Resin ◽

Hybrid Coatings ◽

Formaldehyde Resin ◽

Nacl Solution ◽

Plastic Materials

In this work, the corrosion resistance of hybrid coatings obtained from plastic materials was evaluated and compared with the corrosion resistance of Zn coatings. Zinc and hybrid coatings were obtained by electrodeposition from zinc sulphate electrolyte. For obtained hybrid coatings it was used as disperse phase two type of plastic materials: phenol-formaldehyde resin and epoxy resin. Polarization was used to measure the corrosion rate and behaviour of zinc and hybrid coatings in 3.5% NaCl solution. Tafel curves show that the including particles of plastic materials in zinc matrix disturbs the cathodic reactions and reduces anodic reaction leading to decrease of corrosion current and increase the corrosion resistance of hybrid coatings obtained at the same electrodeposition parameters as zinc coatings. Smallest values of corrosion rate were evaluated for hybrid coatings obtained with phenol-formaldehyde resin as disperse phase that indicates a good corrosion resistance in 3.5% NaCl solution.

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Wettability and Anti-Corrosion Performances of Carbon Nanotube-Silane Composite Coatings

Fibers ◽

10.3390/fib8090057 ◽

2020 ◽

Vol 8 (9) ◽

pp. 57

Author(s):

Luigi Calabrese ◽

Amani Khaskoussi ◽

Edoardo Proverbio

Keyword(s):

Aluminum Alloy ◽

Electrochemical Impedance ◽

Composite Coatings ◽

Sol Gel ◽

Corrosion Current ◽

Nanocomposite Coating ◽

Multi Wall Carbon Nanotubes ◽

Aluminum Corrosion ◽

Order Of Magnitude ◽

The Stability

In this paper, a sol-gel N-propyl-trimethoxy-silane coating filled with different amount of multi-wall carbon nanotubes (MWCNTs) was investigated in order to improve the aluminum corrosion resistance. The nanocomposite coating was applied, by drop casting, on AA6061 aluminum alloy substrate. The morphological analysis highlighted that a uniform sol-gel coating was obtained with 0.4 wt.% CNT. Lower or higher nanotube contents lead to the formation of heterogeneities or agglomeration in the coating, respectively. Furthermore, all nanocomposite coatings exhibited effective adhesion to the substrate. In particular, the pull-off strength ranged in 0.82–1.17 MPa. Corrosion protection of the aluminum alloy in NaCl 3.5 wt.% electrolyte (seawater) was significantly improved after CNT addition to the base coating. The stability in electrochemical impedance was observed during three days of immersion in the sodium chloride solution. AS3-CNT2 and AS3-CNT4 batches showed advanced electrochemical stability during immersion tests. Furthermore, interesting results were evidenced in potentiodynamic polarization curves where a decrease of the corrosion current of at least two order of magnitude was observed. Moreover, the breakdown potential was shifted toward noble values. Best results were observed on AS3-CNT6 specimen which exhibited a passivation current density of approximately 1.0 × 10−5 mA/cm2 and a breaking potential of 0.620 V/AgAgClsat.

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