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

Fibers ◽  
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.

Hybrid sol-gel coating incorporated with TiO2 nanosheets and anti-corrosive effects on AA2024-T3

2019 ◽  
Vol 66 (2) ◽  
pp. 215-221 ◽  
Author(s):  
Dongdong Peng ◽  
Kang Huang ◽  
Yuntao He ◽  
Zhan Zhang ◽  
Yi Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Aluminum Alloy ◽  
Electrochemical Impedance ◽  
Salt Spray ◽  
Sol Gel ◽  
Corrosion Current ◽  
Corrosion Resistant ◽  
Content Type ◽  
Tio2 Nanosheets ◽  
Loading Amount

Purpose This paper aims to improve the anti-corrosive properties of aluminum alloy AA2024-T3 by coating of hybrid sol-gel coating incorporated with TiO2 nanosheets and to investigate the effect of nanosheets’ size on the improvement of corrosion-resistant performance. Design/methodology/approach A series of hybrid sol-gel films incorporated with varying amounts of TiO2 nanosheets were developed to enhance the corrosion protection performance of the bare metal. Scanning electron microscopy, transmission electron microscopy and atomic force microscopy were used to investigate the structure and morphology of the coatings obtained. In addition, the corrosion-resistant properties of the coatings were evaluated using salt spray test and electrochemical impedance spectroscopy. Findings The corrosion current was as low as 9.55 × 10-4 µA/cm2 and optimal positive corrosion potential reached −0.6 V when the size and loading amount of TiO2 nanosheet were optimized, resulting in a remarkable improvement in anti-corrosive properties. Originality/value This work first investigates the effect of incorporation of TiO2 nanoparticles on hybrid sol-gel coating on the improvement of anti-corrosive performance of aluminum alloy AA2024-T3.

scholarly journals Zn-Co-CeO2 vs. Zn-Co Coatings: Effect of CeO2 Sol in the Enhancement of the Corrosion Performance of Electrodeposited Composite Coatings

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 704
Author(s):  
Marija Riđošić ◽  
Nebojša D. Nikolić ◽  
Asier Salicio-Paz ◽  
Eva García-Lecina ◽  
Ljiljana S. Živković ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Healing Rate ◽  
Electrochemical Impedance ◽  
Composite Coatings ◽  
Self Healing ◽  
Kelvin Probe ◽  
Artificial Defect ◽  
Volta Potential ◽  
Superior Corrosion Resistance ◽  
The Stability

Electrodeposition and characterization of novel ceria-doped Zn-Co composite coatings was the main goal of this research. Electrodeposited composite coatings were compared to pure Zn-Co coatings obtained under the same conditions. The effect of two ceria sources, powder and home-made sol, on the morphology and corrosion resistance of the composite coatings was determined. During the electrodeposition process the plating solution was successfully agitated in an ultrasound bath. The source of the particles was found to influence the stability and dispersity of plating solutions. The application of ceria sol resulted in an increase of the ceria content in the resulting coating and favored the refinement from cauliflower-like morphology (Zn-Co) to uniform and compact coral-like structure (Zn-Co-CeO2 sol). The corrosion resistance of the composite coatings was enhanced compared to bare Zn-Co as evidenced by electrochemical impedance spectroscopy and scanning Kelvin probe results. Zn-Co doped with ceria particles originating from ceria sol exhibited superior corrosion resistance compared to Zn-Co-CeO2 (powder) coatings. The self-healing rate of artificial defect was calculated based on measured Volta potential difference for which Zn-Co-CeO2 (sol) coatings exhibited a self-healing rate of 73.28% in a chloride-rich environment.

Characteristics of TiCN Film on AZ31 Magnesium Alloy Deposited by Radio Frequency Magnetron Sputtering

2012 ◽  
Vol 189 ◽  
pp. 124-129
Author(s):  
Jia Mu Huang ◽  
Xi Meng ◽  
Wei Chen ◽  
Shi Yu Sui
Keyword(s):  
Magnesium Alloy ◽  
Magnetron Sputtering ◽  
Radio Frequency ◽  
Electrochemical Impedance ◽  
Corrosion Current ◽  
Radio Frequency Magnetron ◽  
Az31 Magnesium Alloy ◽  
Titanium Carbonitride ◽  
Radio Frequency Magnetron Sputtering ◽  
Order Of Magnitude

Titanium carbonitride (TiCN) films were deposited on AZ31 magnesium alloy by radio frequency magnetron sputtering. The surface morphology and microstructure were investigated by scanning electron microscopy (SEM) and X-ray diffraction (XRD), and the corrosion resistance was studied by potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS). The results show that TiCN coatings deposited on AZ31 magnesium alloy are amorphous, and reveal good adhesion onto the substrate. The corrosion current density of TiCN-coated magnesium alloy was 1.664×10-6 A/cm2, which decreased by more than one order of magnitude compared to the uncoated magnesium alloy (1.785×10-5 A/cm2).

Phosphate-doped polyaniline/Al2O3 nanocomposite coating for protection of stainless steel

2020 ◽  
Vol 67 (5) ◽  
pp. 491-499
Author(s):  
Abou-Elhagag A. Hermas ◽  
Mostafa H. Wahdan ◽  
Eatemad M. Ahmed
Keyword(s):  
Stainless Steel ◽  
Chloride Solution ◽  
Electrochemical Impedance ◽  
Composite Coatings ◽  
Nanocomposite Coating ◽  
Phosphate Solution ◽  
Content Type ◽  
Doped Polyaniline ◽  
Microscopy Techniques ◽  
Pani Layer

Purpose This work aims to prepare and characterize of protective anticorrosion phosphate-doped polyaniline (PANI) nanocomposite coatings for stainless steel (SS) in chloride solution. Design/methodology/approach PANI composite coatings were electrodeposited from aqueous sulfuric acid solution containing monomer and Al2O3 nanoparticles using cyclic voltammetry technique. Doping by phosphate was done by aging the coated steels for different periods (1–168 h) in phosphate solution. The polymer film composite was investigated by Fourier-transform infrared spectroscopy and scanning electron microscopy techniques. Potential-time, anodic polarization and electrochemical impedance spectroscopy were used to study the protection efficiency of the coatings. Findings The Al2O3 nanoparticles were incorporated into the deposited PANI layer but they decreased the deposition of polymer. The nanoparticles and the phosphate anions enhanced the protective PANI layer for passivation and protection of SS in the chloride solution. Originality/value The replacement of counter anions by phosphate ions improved significantly the PANI and its nanocomposite as protective coating of SS in chloride solution.

Electrochemical Characteristics of Al-Based Coating on Magnesium Alloy Fabricated by Supersonic Particles Deposition

2013 ◽  
Vol 756-759 ◽  
pp. 85-88
Author(s):  
Xiao Ming Wang ◽  
Sheng Zhu ◽  
Qing Chang ◽  
Guo Feng Han
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Magnesium Alloy ◽  
Impedance Spectroscopy ◽  
Current Density ◽  
Corrosion Current Density ◽  
Corrosion Potential ◽  
Electrochemical Impedance ◽  
Corrosion Current ◽  
Electrochemical Characteristics ◽  
Order Of Magnitude

Al-based coating on ZM5 magnesium alloy was prepared by Supersonic Particles Deposition (SPD). Electrochemical working station was utilized to test polarization curve, corrosion potential and electrochemical impedance spectroscopy etc. The results indicted that corrosion potential of Al-Si coating was about-767.6mV, much higher than that of ZM5 Mg-substrate; And corrosion current density of the coating sample decreased three order of magnitude than that of the uncoated. Compared to Mg-substrate, the radius of capacitive impedance arc of the coating enlarged and impedance modulus improved two order of magnitude.

Research on the Corrosion Resistance of Ni-ZrO2 Nanocomposite Coatings

2014 ◽  
Vol 633-634 ◽  
pp. 787-790
Author(s):  
Lin Wang ◽  
Jin Lin Lu ◽  
Cheng Wei Li ◽  
Shu Mei Kang
Keyword(s):  
Corrosion Resistance ◽  
Current Density ◽  
Composite Coatings ◽  
Process Condition ◽  
Corrosion Current ◽  
Bath Temperature ◽  
Nanocomposite Coating ◽  
Test Method ◽  
Optimum Process ◽  
Orthogonal Test Method

In order to improve the corrosion resistance of Ni-nanoZrO2 composite coatings. By orthogonal test method,the process for composite electroplating of Ni-ZrO2 was optimized involved current density、bath temperature、the ZrO2 particle concentration. Corrosion resistance and the hardness were tested, microstructure was observed with a scanning electron microscope. The optimized technological conditions are:current density i4A/dm2,bath temperature 45°C, nanoZrO2 addition 7g/L. In this optimum process condition, corrosion current density is 6.186×10-6 A/cm2, corrosion resistance is good, and its hardness is much better than pure nickel plating, also a flat morphology and compact microstructure Ni-ZrO2 nanocomposite coating is get.

Impedance Behavior of the Composite Coatings Prepared on Magnesium Alloy AZ91 in Simulated Seawater Solution

2014 ◽  
Vol 900 ◽  
pp. 526-530
Author(s):  
Wei Shang ◽  
Zhou Lan Yin ◽  
Yu Qing Wen ◽  
Xu Feng Wang
Keyword(s):  
Magnesium Alloy ◽  
Corrosion Protection ◽  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Composite Coatings ◽  
Sol Gel ◽  
Soaking Time ◽  
Magnesium Alloy Az91 ◽  
Micro Arc Oxidation ◽  
Simulated Seawater

The composite coatings were obtained on a magnesium alloy by micro-arc oxidation and sol-gel technique. Electrochemical impedance spectroscopy (EIS) was used to evaluate the corrosion behavior of MAO coating and composite coatings in a simulated seawater solution. The results show that corrosion behavior of the MAO coating and composite coatings are different at different immersion times. Corrosion protection of the MAO coating gradually weaken with the extension of soaking time, but corrosion protection of the composite coatings become stronger first and then weaken.

Alumina Sol-Gel Films and Alodine Films on Al 2024 Alloy

2011 ◽  
Vol 356-360 ◽  
pp. 364-367
Author(s):  
Qi Zhou ◽  
Xuan Xiao ◽  
Da Li Zhao ◽  
En Jun Song
Keyword(s):  
Corrosion Resistance ◽  
Aluminium Alloy ◽  
Electrochemical Impedance ◽  
Sol Gel ◽  
Film Surface ◽  
Corrosion Current ◽  
Promising Alternative ◽  
Gel Film ◽  
Alumina Sol ◽  
Sol Gel Films

Development of the sol-gel films for painting pretreatment of aluminium alloy is to replace bichromate conversion films such as Alodine. Corrosion resistance of Alodine film and sol-gel film were evaluated through potentiodynamic polarization curves, electrochemical impedance spectroscopy, salt spraying and acidic dropping solution. Sol-gel film is almost the same as Alodine film at the film surface density, salt spraying resistance and adhesion with painting coating. Changing color times of dropping solution on sol-gel film is shorter than Alodine film. But the corrosion current of sol-gel film is lower than Alodine and the impedance value is higher than Alodine in 35g/L NaCl solution. Mechanism of corrosion resistance of alumina sol-gel film is that the cathode reaction and anodic reactions are restrained by sol-gel film in the Cl- corrosive medium. The EIS of sol-gel film consisted of only a single capacitive arc with one time constant. Sol-gel coating can prevent or delay the corrosive solution from infiltrating the substrate for its better isolation function, thus protecting 2024 aluminium alloy from corrosion. Sol-gel films can improve corrosion resistance of aluminum alloy and have the same adhesion as Alodine film. It will be a promising alternative pretreatment for aluminum alloys prior to painting.

Formation of Protective Coatings on AMg3 Aluminum Alloy Using Fluoropolymer Nanopowder

2020 ◽  
Vol 312 ◽  
pp. 330-334
Author(s):  
Valeriia S. Filonina ◽  
Konstantine V. Nadaraia ◽  
Dmitry V. Mashtalyar ◽  
Andrey S. Gnedenkov ◽  
Igor M. Imshinetsky ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Isopropyl Alcohol ◽  
Protective Coatings ◽  
Composite Coatings ◽  
Protective Properties ◽  
Composite Layers ◽  
Electrolytic Oxidation ◽  
Order Of Magnitude ◽  
Plasma Electrolytic ◽  
Subsequent Modification

The paper presents the results of a study of the protective properties of composite coatings obtained on AMg3 aluminum alloy by plasma electrolytic oxidation (PEO) and subsequent modification of formed oxide layer with superdispersed polytetrafluoroethylene (SPTFE) from a suspension based on isopropyl alcohol. The incorporation of fluoropolymer decreased the porosity of base PEO-coating more than one order of magnitude. Formed composite layers increased wearproof of the samples by more than two orders of magnitude in comparison with PEO-coating. Additionally, polymer-containing coatings has higher adhesion compared to substrate. Formed composite layers possess superhydrophobic properties: contact angle attains 155°.

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