Corrosion Assessment of Zinc-Rich Primers Containing Polyaniline and the Effect of Acid as a Dopant

CORROSION ◽  
10.5006/2769 ◽  
2018 ◽  
Vol 74 (10) ◽  
pp. 1141-1157 ◽  
Author(s):  
Ximing Li ◽  
Yenny Cubides ◽  
Zhouying He ◽  
Mark D. Soucek ◽  
Homero Castaneda
Keyword(s):  
Barrier Properties ◽  
Nacl Solution ◽  
Corrosion Performance ◽  
Phenylphosphonic Acid ◽  
Interfacial Activation ◽  
Inorganic Acids ◽  
Three Stages ◽  
Corrosion Assessment ◽  
Zinc Particle ◽  
Anticorrosion Properties

We investigated how adding the dopant acid for polyaniline (PAni)-containing zinc-rich primers (ZRPs) can influence the resulting ZRP’s corrosion performance. Two organic acids (camphorsulfonic [CS] and phenylphosphonic acid [H2PP]), and two inorganic acids (phosphoric [H2PO4] and hydrochloricacid [HCl]) were tested and the different PAni-modified ZRPs exhibited differences in their cathodic protection and barrier mechanisms during exposure to a 3.5 wt% NaCl solution. The hydrochloricacid-doped PAni-containing ZRP had the best anticorrosion properties in terms of the zinc particle interfacial activation (sacrificial) and coating’s barrier properties. Corrosion resistance of the coating systems can be ranked as PAni-Cl > PAni-H2PO4 > PAni-HPP ≥ PAni-CS. The corrosion assessment of these coatings can be explained in terms of three stages: the activation stage of the zinc particles, the competition stage, and the steady state stage.

scholarly journals Microstructure and Corrosion Properties of La2Zr2O7/NiCoAlY Thermal Barrier Coatings Deposited on Inconel 718 Superalloy by Laser Cladding

Coatings ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 101
Author(s):  
Kaijin Huang ◽  
Wei Li ◽  
Kai Pan ◽  
Xin Lin ◽  
Aihua Wang
Keyword(s):  
Corrosion Resistance ◽  
Thermal Barrier Coating ◽  
Laser Cladding ◽  
Inconel 718 ◽  
Electrochemical Techniques ◽  
Thermal Barrier ◽  
Nacl Solution ◽  
Corrosion Performance ◽  
Barrier Coating ◽  
Inconel 718 Superalloy

In order to improve the seawater corrosion resistance of Inconel 718 superalloy, a La2Zr2O7/NiCoCrAlY thermal barrier coating corrosion resistant to 3.5 wt.% NaCl aqueous solution was prepared by laser cladding on Inconel 718 superalloy. X-ray diffraction (XRD), Scanning Electron Microscope (SEM), and electrochemical techniques were used to study the microstructure and the corrosion performance of the coating in 3.5 wt.% NaCl solution. The results show that the thermal barrier coating is mainly composed of primary La2Zr2O7 phase and γ + laves/δ phase eutectic structure. The corrosion potential and corrosion current of the coating in 3.5 wt.% NaCl solution are higher and lower than that of the Inconel 718 substrate, respectively, indicating that the corrosion performance of the coating is better than that of the Inconel 718 substrate. The presence of La2Zr2O7 phase in the thermal barrier coating is the main reason for its corrosion resistance to 3.5 wt.% NaCl solution.

Effect of Cr and Zr Addition on the Corrosion Behaviour of Copper in the Chloride Solution

2011 ◽  
Vol 194-196 ◽  
pp. 1253-1256
Author(s):  
Ya Ni Zhang ◽  
Mao Sheng Zheng ◽  
Jie Wu Zhu
Keyword(s):  
Corrosion Resistance ◽  
Chloride Solution ◽  
Corrosion Behaviour ◽  
Pure Copper ◽  
Base Material ◽  
Nacl Solution ◽  
Corrosion Performance ◽  
Zr Addition ◽  
Corrosion Scales ◽  
Better Than

The corrosion behavior of CuCr, CuZr and CuCrZr alloys in NaCl solution is reported in this paper. The corrosion performance has been evaluated in NaCl solution atmosphere. The results show the corrosion resistance of pure copper decrease with the addition of the alloying elements initially. However, in the later exposure stages, the corrosion resistance of CuZr and CuCrZr alloy deteriorates significantly while the corrosion resistance of CuCr alloy is slightly better than that of pure copper. In addition, the results of the electrochemical experiments indicate that the different behavior for the element Cr and Zr in the base material and corrosion scales lead to the change of the corrosion resistance.

Corrosion Resistance of Nd-Fe-B Magnets Coated with Polypyrrole Films

2006 ◽  
Vol 530-531 ◽  
pp. 111-116
Author(s):  
M.C.E. Bandeira ◽  
F.D. Prochnow ◽  
Isolda Costa ◽  
César V. Franco
Keyword(s):  
Corrosion Resistance ◽  
Electrochemical Impedance ◽  
Nacl Solution ◽  
Corrosion Performance ◽  
Low Frequencies ◽  
Polypyrrole Films ◽  
Phosphate Ions ◽  
Polypyrrole Film ◽  
Corrosive Environments ◽  
Magnet Surface

Nd-Fe-B magnets present outstanding magnetic properties. However, due to their low corrosion resistance, their applications are limited to non-corrosive environments. Nowadays, significant efforts are underway to increase the corrosion resistance of these materials, through the use of coatings. Herein are presented the results of a study on the corrosion resistance of Nd-Fe-B magnets coated with polypyrrole (PPY). The electrochemical behavior of coated and uncoated magnets has been studied by Electrochemical Impedance spectroscopy (EIS) in synthetic saliva. The results were compared to previous investigations, which were carried out under similar conditions, in Na2SO4 and NaCl solutions. In sulphate solution, the corrosion resistance of the PPY-coated magnet was 3 times larger (1600 .cm2) than that of uncoated magnet (500 .cm2). In NaCl solution, however, the corrosion resistance of coated and uncoated magnets were very similar (250 .cm2). In synthetic saliva, both the uncoated and coated magnets presented good corrosion performance (1940 .cm2). Such behavior can be attributed to the phosphate ions in saliva, which play a role as corrosion inhibitor, producing phosphating, at least partially, of the magnet surface. The PPY-coated magnets presented a strong diffusional control from moderate to low frequencies, caused by the polypyrrole film. The thicker PPY film increased the corrosion resistance of the magnet in synthetic saliva.

Corrosion Protection Coatings from Size-Specified Graphene Oxide

2020 ◽  
Vol 981 ◽  
pp. 29-33
Author(s):  
Nurul Huda Abu Bakar ◽  
Jamil Ismail ◽  
Kwok Feng Chong
Keyword(s):  
Graphene Oxide ◽  
Corrosion Protection ◽  
Surface Texture ◽  
Copper Substrate ◽  
Smooth Surfaces ◽  
Nacl Solution ◽  
Corrosion Performance

Corrosion performance of graphene oxide (GO) coatings from different sheets sizes in 3.5 wt% NaCl solution was investigated. The GO dispersion was subjected to 5 and 10 hours of ultrasonication before electrophoretically deposited (EPD) onto the copper substrate. It was found that the EPD-GO coating from smaller sheets (10h ultrasonication) possess hydrophobic, thinner film and smooth surfaces. It is suggested that the corrosion performance of the coating from smaller GO sheets is improved due to the surface texture and compactness of the coating as compared to the larger GO sheets.

Effect of Manganese on Discharge and Corrosion Performance of Magnesium Alloy AP65 as Anode for Seawater-Activated Battery

CORROSION ◽  
2012 ◽  
Vol 68 (5) ◽  
pp. 388-397 ◽  
Author(s):  
N.-G. Wang ◽  
R.-C. Wang ◽  
C.-Q. Peng ◽  
Y. Feng
Keyword(s):  
Magnesium Alloy ◽  
Mass Fraction ◽  
Electrochemical Measurement ◽  
The Self ◽  
Discharge Process ◽  
Nacl Solution ◽  
Corrosion Performance ◽  
Corrosion Morphology ◽  
Immersion Testing ◽  
Discharge Potential

Magnesium alloys AP65 with and without 0.3% (mass fraction) manganese additions were prepared by melting and casting. Their discharge and corrosion behavior in 3.5% sodium chloride (NaCl) solution was investigated with electrochemical measurement, immersion testing, and corrosion morphology observation. The results show that manganese promotes the grain refinement and reduces the self corrosion rate of AP65 alloy. Magnesium alloy AP65 added with manganese provides a more negative discharge potential than that without the addition of manganese, attributed to the homogeneously distributed Al11Mn4 particles, which facilitate the self-peeling of corrosion products during the discharge process. This means that the discharge and corrosion performance of AP65 alloy can be improved by adding manganese.

scholarly journals Graphene Oxide/Polyaniline Nanocomposites Used in Anticorrosive Coatings for Environmental Protection

Coatings ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1215
Author(s):  
Shuanqiang Yang ◽  
Shu Zhu ◽  
Ruoyu Hong
Keyword(s):  
Graphene Oxide ◽  
Electrochemical Impedance ◽  
In Situ Polymerization ◽  
Barrier Properties ◽  
Living Environment ◽  
Metal Corrosion ◽  
Corrosion Performance ◽  
Corrosion Properties ◽  
Anticorrosive Coatings ◽  
Vis Spectroscopy

In recent years, metal corrosion causes serious threats to the economy of the world and the living environment. Hence, it is very important to seek non-toxic and environmentally friendly materials with metal anti-corrosion properties for the sustainable development of society. The barrier properties of graphene oxide (GO) and the special electrochemical property of polyaniline (PANI) can significantly improve the corrosion resistance of metals. Herein, we developed an in-situ polymerization method to prepare graphene oxide/polyaniline (GO/PANI) nanocomposites with unique anti-corrosion properties. The obtained GO/PANI nanocomposites were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, thermalgravimetric analysis, UV–vis spectroscopy and scanning electron microscopy. The as-prepared composite materials were uniformly dispersed in epoxy resin to prepare anticorrosive coatings and coated on the surface of steel. The anti-corrosion performance of the coatings was measured by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization technique. The EIS results showed that the total impedance of epoxy/GO/PANI coatings is greater than epoxy/PANII coatings, and the impedance module value can reach 8.67 × 108 Ω·cm2. In general, it is concluded that the anti-corrosion performance of GO/PANI coating is significantly higher than PANI coating and pure GO coating.

Effect of Polymer Modified Cement-Based Coatings on Steel Bars Anticorrosion and Bond Properties between Coated Bars and Concrete

2013 ◽  
Vol 368-370 ◽  
pp. 1066-1069
Author(s):  
Zhi Yong Liu ◽  
Lei Yu ◽  
Da Ji Li ◽  
Kun Rong Wang
Keyword(s):  
Chloride Solution ◽  
Bond Properties ◽  
Nacl Solution ◽  
Chloride Permeability ◽  
Pullout Tests ◽  
Uncoated Steel ◽  
Steel Bars ◽  
Acrylate Emulsion ◽  
Epoxy Emulsion ◽  
Anticorrosion Properties

In this paper the anticorrosion properties of steel bars coated with polymer modified cement-based coatings in chloride solution were evaluated. Then the pullout tests were conducted using coated and uncoated steel bars embedded in concrete specimens and the bond properties between concrete and bars were tested. The results show the steel bars coated with epoxy emulsion modified cement-based coating (HY) and elastic copolymer emulsion modified cement-based coating (GT) have satisfactory anticorrosion properties in 3.5% NaCl solution for 96h. But the pullout tests display that the bond strength between the concrete and the steel bars coated with GT coating is much lower than that of the bars coated with HY coating and the uncoated specimens. The bond stress between the concrete and the bars coated with pure acrylate emulsion modified cement-based (CB) coating is the highest among the three coatings, but the resistance to chloride permeability of CB coating is poor. The results indicate the special epoxy-cement-based coating (HY) is more suitable for applying to the anticorrosion coating for steel bars in chloride condition.

Sign in / Sign up

Export Citation Format

Share Document