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.

Effects of potassium silicate on corrosion behavior of dacromet coating

2019 ◽  
Vol 66 (6) ◽  
pp. 819-826
Author(s):  
Khashayar Tabi ◽  
Mansour Farzam ◽  
Davood Zaarei
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Automobile Industry ◽  
Electrochemical Impedance ◽  
Salt Spray ◽  
Corrosion Current ◽  
Potassium Silicate ◽  
Coated Steel ◽  
Content Type ◽  
New Information

Purpose Potassium silicate sealer was applied on solvent-cleaned, acid-pickled, dacromet-coated steel to improve its corrosion resistance. The purpose of this paper is to study the corrosion behavior of dacromet-coated steel. Design/methodology/approach Potassium silicate sealer was applied on solvent-cleaned, acid-pickled, dacromet-coated steel to improve its corrosion resistance. Electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and salt spray were carried out. SEM was used to study the morphological appearance of the surface. Findings The EIS behavior indicated that solvent-cleaned dacromet-coated steel sealed with potassium silicate showed that the corrosion current density was 2.664E − 5 A.cm2 which was reduced to 8.752E − 6 A.cm2 and the corrosion rate, which was 2.264E − 2 mm.year−1, was reduced to 7.438E − 3 mm.year−1 in NaCl 3.5 wt.per cent. EIS was used in NaCl 3.5 wt.%, and the Bode plot characteristics showed that the corrosion protection of solvent-cleaned, dacromet-coated steel was enhanced when sealed with potassium silicate. The EDS results of salt-sprayed, solvent-cleaned samples after 10 days indicated that the main corrosion products are composed of SiO2, ZnO and Al2O3. Research limitations/implications The detection of Li element in EDS was not possible because of the device limitation. Originality/value The current paper provides new information about the sealing properties of potassium silicate and its effects on the corrosion resistance of dacromet coating, which is widely used in many industries such as the automobile industry.

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.

Effective corrosion inhibition performance of La(NO3)3 doped sol-gel coating on galvanized steel sheet

2014 ◽  
Vol 61 (6) ◽  
pp. 370-379 ◽  
Author(s):  
Akshya K. Guin ◽  
M. Bhadu ◽  
Mahua Sinhababu ◽  
Ankita Mundhara ◽  
T.K. Rout ◽  
...  
Keyword(s):  
Hexavalent Chromium ◽  
Steel Sheet ◽  
Electrochemical Impedance ◽  
Salt Spray ◽  
Sol Gel ◽  
Galvanized Steel ◽  
Molecular Vibration ◽  
Suitable Alternative ◽  
Content Type ◽  
Passivation Treatment

Purpose – The aim of this work was to study the effect of La(NO 3 ) 3 on the corrosion behavior of sol-gel coating prepared by hydrolysis of 3-glycidoxypropyl)methyldiethoxysilane and 3-aminopropyltriethoxysilane. Generally, galvanized steel is subjected to a hexavalent chromium passivation treatment. Hexavalent chromium passivation is not an environment friendly product and researchers are looking for a suitable alternative for chromium passivation treatment. Some of the potential alternatives are silicate conversion coating or the use of silane-based coatings. In this context, sol-gel coating was investigated as a potential replacement for hazardous hexavalent chromium passivation treatment. Design/methodology/approach – The sol-gel film was deposited on galvanized steel sheet by the dip coating method. The molecular vibration and chemical properties of sol-gel solution and coated films were obtained by infrared spectroscopy. Images from a scanning electron microscope were obtained to characterize the morphology of the film. The corrosion resistance of the coated samples was evaluated by electrochemical impedance spectroscopy (EIS), potentiodynamic polarization curves and salt spray tests. Findings – The results indicated that La(NO 3 ) 3 -doped coatings were more resistance to corrosion than undoped coating. The coating doped with 0.5 per cent La(NO 3 ) 3 offered improved corrosion protection due to the inhibitive action of the La3+ ion. Originality/value – This result can provide a reference for the development of chromium-free passivation for galvanized sheeting.

Preparation and corrosion behavior of cerium (III)-modified and electro-assisted deposited bis-1,2-[triethoxysilyl] ethane film on the aluminum alloy AA2024-T3

2017 ◽  
Vol 64 (1) ◽  
pp. 83-91
Author(s):  
Dongdong Peng ◽  
Junsheng Wu ◽  
Pingping Chu ◽  
Xiaogang Li
Keyword(s):  
Dissolved Oxygen ◽  
Corrosion Behavior ◽  
Marked Effect ◽  
Electrochemical Impedance ◽  
Salt Spray ◽  
Immersion Test ◽  
Self Healing ◽  
Compact Structure ◽  
Corrosion Resistant ◽  
Content Type

Purpose This paper aims to investigate the effect of cerium modification and electrodeposition on the properties of the silane films obtained. Besides, the influence of dissolved oxygen was also researched through inhalation of oxygen or nitrogen. Moreover, the corresponding corrosion behavior of the silane films was also studied. Design/methodology/approach In this paper, surface morphology and corrosion-resistant properties of the films were characterized by scanning electron microscopy, electrochemical impedance spectroscopy, immersion test and the salt spray test. Findings The paper reveals that all the practical parameters including the concentration of dissolved oxygen had a marked effect on the anti-corrosive performance of the films, which may be attributed to the dense and compact structure of the films obtained. Furthermore, the self-healing ability of the films had also been enhanced through the rise of dissolved oxygen concentration in proper proportion. Originality/value This paper reveals the effect of practical parameters on the properties of the silane films obtained and the corrosion behavior of these films.

scholarly journals Using Graphene-Based Composite Materials to Boost Anti-Corrosion and Infrared-Stealth Performance of Epoxy Coatings

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1603
Author(s):  
Meng-Jey Youh ◽  
Yu-Ren Huang ◽  
Cheng-Hsiung Peng ◽  
Ming-Hsien Lin ◽  
Ting-Yu Chen ◽  
...  
Keyword(s):  
Electrochemical Impedance ◽  
Graphene Nanosheets ◽  
Salt Spray ◽  
Corrosion Current ◽  
Filler Concentration ◽  
Epoxy Coatings ◽  
Corrosion Properties ◽  
Water Contact ◽  
Different Temperatures ◽  
Thermal Signature

Corrosion prevention and infrared (IR) stealth are conflicting goals. While graphene nanosheets (GN) provide an excellent physical barrier against corrosive agent diffusion, thus lowering the permeability of anti-corrosion coatings, they have the side-effect of decreasing IR stealth. In this work, the anti-corrosion properties of 100-μm-thick composite epoxy coatings with various concentrations (0.01–1 wt.%) of GN fillers thermally reduced at different temperatures (300 °C, 700 °C, 1100 °C) are first compared. The performance was characterized by potentiodynamic polarization scanning, electrochemical impedance spectroscopy, water contact angle and salt spray tests. The corrosion resistance for coatings was found to be optimum at a very low filler concentration (0.05 wt.%). The corrosion current density was 4.57 × 10−11 A/cm2 for GN reduced at 1100 °C, showing no degradation after 500 h of salt-spray testing: a significant improvement over the anti-corrosion behavior of epoxy coatings. Further, to suppress the high IR thermal signature of GN and epoxy, Al was added to the optimized composite at different concentrations. The increased IR emissivity due to GN was not only eliminated but was in fact reduced relative to the pure epoxy. These optimized coatings of Al-GN-epoxy not only exhibited greatly reduced IR emissivity but also showed no sign of corrosion after 500 h of salt spray test.

scholarly journals ESTUDIO DE LA RESISTENCIA A LA CORROSION DEL ALUMINIO 6063 ANODIZADO

2017 ◽  
Vol 22 (2) ◽  
pp. 17
Author(s):  
Karín Paucar Cuba ◽  
Hugo Rojas Flores ◽  
Abel Vergara Sotomayor
Keyword(s):  
Corrosion Resistance ◽  
Aluminum Alloy ◽  
Sulfuric Acid ◽  
Electrochemical Impedance ◽  
Salt Spray ◽  
Aluminum Surface ◽  
Equivalent Circuits ◽  
Acid Salt ◽  
Mass Losses ◽  
Palabras Clave

El estudio de la resistencia a la corrosión del anodizado de una aleación de aluminio (AA6063) en ácido sulfúrico a diferentes tiempos de anodizado: 30, 45 y 60 min. se realizó usando la espectroscopia de impedancia electroquímica (EIE) y el ensayo de niebla salina ácida. (ASTM B287). Los datos obtenidos por EIE y su correlación con los circuitos equivalentes más apropiados permitieron determinar los parámetros asociados a la capa porosa y a la capa barrera del óxido protector formado sobre la superficie del aluminio en estudio. La exposición de las muestras anodizadas durante 250h a una niebla salina ácida permitió observar variaciones en su masa. De los resultados obtenidos por EIE y las pérdidas de masa de las muestras anodizadas se estableció que la película de anodizado de 45 minutos mostró una mayor resistencia a la corrosión en comparación con la obtenida a 60 y 30 min., respectivamente. Palabras clave.- Aluminio, Anodizado, Impedancia electroquímica, Niebla salina ácida. ABSTRACTThe study of the corrosion resistance of anodized on aluminum alloy (AA6063) in sulfuric acid to different times: 30, 45 and 60 min. was performed using electrochemical impedance spectroscopy (EIS) and the acid salt spray test (ASTM B287). The EIS’data and its correlation with the most appropriate equivalent circuits allowed to determine the parameters associated with the porous layer and the oxide layer protective barrier formed on the aluminum surface under study. Exposure of the samples anodized for a 250h salt spray acid allowed to observe changes in their mass. From the results obtained by EIS and the mass losses of the anodized samples was established that the anodized film of 45 minutes showed higher corrosion resistance compared to that obtained at 60 and 30 min, respectively. Keywords.- Aluminum, Anodized, Electrochemical impedance, Acid salt spray.

Effect of narrow pulse width laser cleaning on corrosion resistance of A5083-H111 aluminum alloy

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Feisen Wang ◽  
Sifei Ai ◽  
Qian Wang ◽  
Yinfen Cheng ◽  
Haiqi Huang ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Aluminum Alloy ◽  
Surface Morphology ◽  
Elemental Composition ◽  
Pulse Width ◽  
Salt Spray ◽  
Laser Cleaning ◽  
Elemental Distribution ◽  
Content Type ◽  
Poor Area

Purpose The purpose of this paper is to promote the corrosion resistance of the 5083-111H aluminum alloy by laser cleaning. Design/methodology/approach Laser with 2 ns pulse width was adopted in this project and the corrosion resistance of cleaned samples was tested by copper-accelerated salt spray (CASS). The surface morphology, elemental composition and distribution were then characterized by SEM. Moreover, surface morphology, elemental composition and distribution were also tested. Findings Results suggested a higher corrosion resistance was successfully obtained by laser cleaning. Compared with samples cleaned by 2000 grit sandpaper, mechanical cleaning resulted in a 53% larger height difference between the peak and valley. The content of the oxygen is 8.85% on the surface cleaned mechanically and the distribution is dependent on the distribution of aluminum whereas that of the laser cleaning sample is 24.41% and the distribution existed even in the Al-poor area. Originality/value In this project, the 2-ns laser cleaning was proved to have the capability to remove the oxide layer on the aluminum alloy surface while retaining an excellent corrosion resistance and smooth surface. Meanwhile, a thorough elemental distribution and smaller grain size lead to a smaller difference in elemental concentration. This retards the diffusion of oxygen into the substrate and hence increases the corrosion resistance of the surface.

Corrosion resistance of composite coating used for fastener protection

2019 ◽  
Vol 66 (5) ◽  
pp. 595-602
Author(s):  
Zhifeng Lin ◽  
Likun Xu ◽  
Xiangbo Li ◽  
Li Wang ◽  
Weimin Guo ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Carbon Steel ◽  
Composite Coating ◽  
Marine Environment ◽  
Electrochemical Impedance ◽  
Salt Spray ◽  
Diffusion Method ◽  
Economic Losses ◽  
Neutral Salt ◽  
Content Type

Purpose The purpose of this paper is to examine the performance of a fastener composite coating system, sherardized (SD) coating/zinc-aluminum (ZA) coating whether it has good performance in marine environment. Design/methodology/approach In this paper, SD coating was fabricated on fastener surface by solid-diffusion method. ZA coating was fabricated by thermal sintering method. Corrosion behaviours of the composite coating were investigated with potentiodynamic polarization curves, open circuit potential and electrochemical impedance spectroscopy methods. Findings Neutral salt spray (NSS) and deep sea exposure tests revealed that the composite coating had excellent corrosion resistance. Polarization curve tests showed that corrosion current density of the sample with composite coating was significantly decreased, indicating an effective corrosion protection of the composite coating. OCP measurement of the sample in NaCl solution demonstrated that the composite coating had the best cathodic protection effect. The good corrosion resistance of the composite coating was obtained by the synergy of SD and ZA coating. Practical implications SD/ZA coating can be used in marine environment to prolong the life of carbon steel fastener. Social implications SD/ZA composite coating can reduce the risk and accident caused by failed fastener, avoid huge economic losses. Originality/value A new kind of composite coating was explored to protect the carbon steel fastener in marine environment. And the composite coating has the long-term anti-corrosion performance both in simulated and marine environment test.

Effect of Sol-Gel Film on the Corrosion Resistance of Low Carbon Steel Plate

2020 ◽  
Vol 984 ◽  
pp. 43-50
Author(s):  
Hua Yuan Zhang ◽  
Can Wang ◽  
Bing Xue ◽  
Jing Luo
Keyword(s):  
Corrosion Resistance ◽  
Carbon Steel ◽  
Steel Plate ◽  
Salt Spray ◽  
Sol Gel ◽  
Low Carbon Steel ◽  
Corrosion Current ◽  
Neutral Salt ◽  
Low Carbon ◽  
Gel Film

To improve the corrosion resistance on Q235 low carbon steel, in this paper, tetraethyl orthosilicate (TEOS), N-dodecyl trimethoxysilane and γ-(2,3-epoxypropoxy) propytrimethoxysilane (KH560) were used to make organic-inorganic hybrid sol-gel film. Cross cut test adhesion method, neutral salt spray test, electrochemical test and film protective efficiency were taken to value the corrosion resistance property. The corrosion topography was studied by optical microscope. In addition, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) curves and equivalent electric circuit fitting were used to analyze the corrosion mechanism. The cross cut adhesion of sol-gel film can reach 1 class and the protection class can attain 5 class after 72 hours neutral salt spray test. According to the potentiodynamic polarization curve analysis, the corrosion potential of sol-gel film coating sample after 0.5 hours immersion was -0.46 V (vs. SCE) on the 0.1 Hz, and its corrosion current density was 4.74×10-7 A·cm-2. The corrosion potential of bare Q235 low carbon steel plate after 0.5 hours immersion was -0.78 V (vs. SCE) on the 0.1 Hz, and its corrosion current density was 4.75×10-6 A·cm-2. The impedance value on 0.1 Hz (|Z|0.1Hz) (1.27×106 Ω·cm2) of sol-gel film coating sample was more than three orders of magnitude higher than the value of the low carbon steel plate. Even dipping in 3.5 wt. % NaCl for 72 hours, the |Z|0.1Hz value of sol-gel coating sample was still one order of magnitude higher than the low carbon steel plate with 0.5 hours immersion. Sol-gel film with excellent adhesion can significantly improve the corrosion resistance of low carbon steel plate. Sol-gel film can increase the protection efficiency of low carbon steel plate by 90%.

Phenalkamine curing agents for epoxy resin: characterization and structure property relationship

2018 ◽  
Vol 47 (4) ◽  
pp. 281-289 ◽  
Author(s):  
Kunal Wazarkar ◽  
Anagha S. Sabnis
Keyword(s):  
Epoxy Resin ◽  
Electrochemical Impedance ◽  
Salt Spray ◽  
Structure Property ◽  
Cashew Nut Shell Liquid ◽  
Performance Properties ◽  
Content Type ◽  
Cashew Nut ◽  
Curing Agents ◽  
Cashew Nut Shell

Purpose The purpose of this study is to synthesize structurally different phenalkamines based on cardanol, a renewable material obtained from cashew nut shell liquid, and to evaluate their effect on performance properties of the coatings. Design/methodology/approach For this purpose, the Mannich reaction between cardanol, formaldehyde and various diamines such as diaminodiphenyl methane (DDM), hexamethylene diamine, Jeffamine D400 and Jeffamine T403 were carried out to produce novel phenalkamines. Resultant phenalkamines were used as curing agents for commercial DGEBPA epoxy resin and were evaluated for performance properties. Findings The mechanical, optical, chemical, thermal and anticorrosive properties were evaluated and compared with those of commercial phenalkamine AG141. It was observed that anticorrosive properties evaluated using a salt spray test and electrochemical impedance spectroscopy revealed significant improvement in anticorrosive performance of coatings cured with synthesized phenalkamines based on DDM and T403 as compared to the coatings based on commercial phenalkamine AG141. Research limitations/implications To obtain optimum performance properties of the coatings, a combination of phenalkamines can be used. Practical implications Curing time and gel times of all the phenalkamines can be further studied under wet and humid conditions. In addition, the variation in coating properties under humid conditions can be investigated. Originality/value In this study, newer phenalkamines were synthesized and used as curing agents for epoxy coatings. So far, there have been no reports indicating the synthesis and application of phenalkamines based on polyetheramines, namely, Jeffamine D400 and Jeffamine T403, in coating applications.

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