Journal articles: 'Composite electrochemical coatings'

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Yudina, E. M., Yu E. Kisel, M. R. Kadyrov, and A. S. Serguntsov. "Service properties of composite electrochemical coating." MATEC Web of Conferences 344 (2021): 01022. http://dx.doi.org/10.1051/matecconf/202134401022.

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The article considers the ways of solving problems, regarding the rework and durability improvement of elements of industrial equipment. One of the ways to restore and improve the operational properties of machinery parts is the application of galvanic coatings, in particular, composite galvanic coatings. The article shows ways to improve the performance properties of composites, determines the optimal content of the dispersed phase in the composite, in terms of the ratio of the strength of the dispersed phase and matrix. The composite electrochemical coating wear resistance and the roughness of composites under conditions of abrasive wear have been explored. The relationship between the wear resistance and the surface roughness during wear has been determined. In an experimental study of the composite coatings abrasive wear resistance, it was found that their wear largely depends on the size and volume content of dispersed particles in the coating. It has been experimentally proven that the composite coating roughness depends on the matrix mechanical properties, the content and size of disperse particles.

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Kim, Sumin, Clare Chisu Byeon, and Sung Yeol Kim. "Electrochemical Response of Clay/Polyelectrolyte Composite Barrier Coatings." Coatings 10, no. 12 (November 30, 2020): 1173. http://dx.doi.org/10.3390/coatings10121173.

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Composite materials made of polymer and clay are effective at blocking mass transport. In this study, the blocking efficacy of layer-by-layer (LbL) coatings of exfoliated montmorillonite (MMT) and polyethylenimine (PEI) was studied using cyclic voltammetry and a redox couple, indigo carmine (IC). The pH of the MMT solution was varied from 4 to 10 to prepare LbL coatings of different surface roughness on metal substrates. It was found that the coated electrode had a lower redox peak current value than without the coating, demonstrating the reduction of the mass transport of IC to the metal surface. The peak values decreased with decreasing the coating’s roughness and increasing the number of layers, indicating that the blocking capability can be controlled by changing the deposition conditions. Smooth LbL coatings deposited with MMT at pH 4 showed the highest blocking efficacy up to 97.5%. The IC adsorbed at the interface between the coating and the metal substrate was found to cause the peak current measured for the coated electrode. It was also confirmed that the same coating on the copper substrate reduced the corrosion of the copper during the electrochemical potential cycling.

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Li, Mu Qin, Li Jie Qu, Chen Ma, and Shi Qin Yang. "Bioactive and Stability of Calcium Phosphate-Polypyrrole Composite Coatings by Electrochemical Deposition." Key Engineering Materials 368-372 (February 2008): 1198–200. http://dx.doi.org/10.4028/www.scientific.net/kem.368-372.1198.

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This study examined the bioactive and stability of calcium phosphate- polypyrrole(ppy) composite coatings on titanium alloys by electrochemically deposition in simulated body fluid (SBF). Change of coatings mass and SBF pH during coatings soaked in SBF indicated that ppy reduces the decomposition of coatings. The surface morphology of coatings characterized by SEM showed that the stability of composition coating was superior to that of single coating. XRD indicated that ppy induces CO3 2- enter calcium phosphate coating, which showed that the composite coatings possess better bioactive. Thus, this electrochemical deposition provides an effective method of ppy incorporation at physiological temperature, which can offer excellent bioactive and stability of coatings, with a potential for sustained release of therapeutic agents as required for metallic implant fixation.

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Degtyar, L. A., I. S. Ivanina, and I. Yu Zhukova. "Formation features of composite electrochemical nickel and nanostructured zirconium boride coatings." Vestnik of Don State Technical University 19, no. 1 (April 1, 2019): 31–37. http://dx.doi.org/10.23947/1992-5980-2019-19-1-31-37.

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Introduction.The electrodeposition of composite electrochemical coatings from electrolyte-colloid nickel plating containing ultradisperse zirconium boride powder is studied. The work objectives are as follows: to study mechanical-and-physical properties of the composites based on nickel and nanostructured zirconium boride, and to determine optimal conditions for the application of such electrochemical coatings.Materials and Methods.Microhardness of composite electrochemical coatings was measured using PMT-3 microhardness tester on samples with the layer thickness of 30 μm under the indentation load of 100 g. A three-ball machine was used to determine wear resistance of the coatings. Sample tests were carried out under dry friction modes and with the use of 3% RV coolant. WSD values were measured by MIR-3 TU 3-3.1954-86 microscope. To determine the internal stresses in the coating, we used a flexible cathode method up to GOST 9.302-88.Research Results.The electrolyte-colloid composition and modes of electrodeposition of composite nickel - nanostructured zirconium boride coatings are developed. Mechanicaland-physical properties (microhardness, wear resistance and internal stresses) of the obtained composite electrochemical coatings are analyzed. Recommendations for use of the developed electrolyte and the application of a composite coating on machine parts for their surface hardening are formulated.Discussion and Conclusions. Ni–ZrB2 CEC (composite electrochemical coating) has high microhardness (10–11 hPa at the indentation load of 100 g), which exceeds the microhardness of pure nickel by 1.5–2 times. As the microhardness increases, the internal stresses ofNi–ZrB2 CEC decrease. The proposed coatings were compared to chromium ones deposited from the environmentally hazardous electrolytes. The wear resistance ofNi–ZrB2 CEC is 2–5 times higher than that of chromium coatings. Thus, instead of chromic coatings, it is recommended to use the proposed composition for surface hardening of parts of the specialty machinery and industrial equipment

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Guryanov, G. V., and Yu Ye Kisel. "Laser treatment of composite electrochemical coatings." Traktory i sel hozmashiny 80, no. 4 (April 15, 2013): 53–55. http://dx.doi.org/10.17816/0321-4443-65906.

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Results of investigation of laser treatment effect on some mechanical properties of composite electrochemical coatings on the base of iron containing dispersal boron carbide inclusion are given. It was shown that thermal treatment leads to changes of composites microstructure and coatings wear resistance increase.

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Wen, Yu Qing, Hui Min Meng, Wei Shang, and Xiu Juan Jiang. "Electrochemical Characteristics of the Rare Earth Compound Coating on 6061 Aluminum Alloy." Applied Mechanics and Materials 71-78 (July 2011): 2361–65. http://dx.doi.org/10.4028/www.scientific.net/amm.71-78.2361.

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The composite coatings were prepared on aluminum alloy by anodizing and chemical conversion method. The coatings consisted of a anodic oxide coating and a rare earth conversion coating. The surface morphology and composition of the composite coatings were analyzed by scanning electron microscopy (SEM) and energy dispersive X-rays (EDX). The electrochemical properties of the different samples were researched by Potentiodynamic polarisation and electrochemical impedance spectroscopy in a 3.5-wt.% NaCl solution. The results showed that corrosion current density of the sample with composite coatings was 3.611×10-9 A·cm-2, impedance was 6.107×105 Ω·cm-2. The composite coatings had better corrosion resistance than the sample with anodic oxide film and the aluminum alloy substrate.

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Shang, Wei, Zhou Lan Yin, Yu Qing Wen, and Xu Feng Wang. "Corrosion Behavior of the Composite Coatings Prepared on Magnesium Alloy AZ91 in Na₂SO₄ Solution." Advanced Materials Research 900 (February 2014): 522–25. http://dx.doi.org/10.4028/www.scientific.net/amr.900.522.

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The composite coatings were obtained on a magnesium alloy by micro-arc oxidation (MAO) and sol-gel technique. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) were used to evaluate the corrosion behavior of MAO coating and composite coatings in a 3.5% Na2SO4 solution. The results show that corrosion behavior of the MAO coating and composite coatings are different at different immersion times. The corrosion resistance of composite coatings is good than that of MAO coating.

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Abakah, Randy, Feng Huang, Qian Hu, Yicong Wang, and Jing Liu. "Comparative Study of Corrosion Properties of Different Graphene Nanoplate/Epoxy Composite Coatings for Enhanced Surface Barrier Protection." Coatings 11, no. 3 (March 1, 2021): 285. http://dx.doi.org/10.3390/coatings11030285.

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Loading of graphene to polymeric materials has proven a widespread increase in the corrosion properties of nanocomposites. In this study, graphene nanoplatelets (Gnps)/epoxy composite coatings were prepared by incorporating three commercial graphene nanoparticles (C750, M15, and X50 Gnps) into epoxy resin. The morphological impact of the Gnps on the surface barrier protection were evaluated in terms of coating’s adhesion to the substate, hydrophobicity and water uptake performance. Salt spray resistance and Electrochemical Impedance Spectroscopy (EIS) authenticated that the coating integrated with C750 Gnp remarkably improved the anti-corrosion performance of neat epoxy composite coatings. A robust passive layer and surface barrier characteristics formed by the composite coatings incorporated with C750 nanoparticle should be the main reason for better protection properties offered by C750 Gnp/epoxy nanocomposites. At the same time, homogeneous dispersion and lesser agglomerates in C750 Gnp/epoxy composite coatings mainly contributed to the coating’s excessive corrosion resistance.

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Xu, Liping, Jinbing Song, Xiaofeng Zhang, Changguang Deng, Min Liu, and Kesong Zhou. "Microstructure and Corrosion Resistance of WC-Based Cermet/Fe-Based Amorphous Alloy Composite Coatings." Coatings 8, no. 11 (November 6, 2018): 393. http://dx.doi.org/10.3390/coatings8110393.

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There is an urgent need to improve the corrosion resistance of WC-based cermet coatings in different corrosive environments. The main objective of this work was to investigate the microstructure and evaluate the corrosion resistance in neutral, acidic, and alkaline electrolytes of the WC-based cermet/Fe-based amorphous alloy composite coating. Thus, a composite coating of WC–CoCr/Fe-based amorphous alloy and a single WC–CoCr coating were fabricated using the high-velocity oxygen fuel (HVOF) process. The phase composition, microstructure of the original powders, and as-sprayed coatings were studied. The detailed interface information between different compositions of the composite coating was observed by high-resolution transmission electron microscopy (HRTEM). The corrosion resistance of the coatings was studied comparatively by electrochemical tests in 3.5 wt % NaCl, 1 M HCl and 1 M NaOH solutions, respectively. Results showed that the composited coating had a dense layered structure with a composition of WC, Fe-based amorphous alloy, and small amount of W2C. It was revealed that obvious inter-diffusion exists between the interfaces of tungsten carbide/Co, Cr binder and WC–CoCr/Fe-based amorphous alloy. The electrochemical test results showed that the composite coating displayed better corrosion resistance than single WC–CoCr coating both in 3.5 wt % NaCl solution and in 1 M NaOH solution.

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Shang, Wei, Zhou Lan Yin, Yu Qing Wen, and Xu Feng Wang. "Impedance Behavior of the Composite Coatings Prepared on Magnesium Alloy AZ91 in Simulated Seawater Solution." Advanced Materials Research 900 (February 2014): 526–30. http://dx.doi.org/10.4028/www.scientific.net/amr.900.526.

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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.

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Popczyk, Magdalena. "The Hydrogen Evolution Reaction on Electrolytic Nickel-Based Coatings Containing Metallic Molybdenum." Materials Science Forum 636-637 (January 2010): 1036–41. http://dx.doi.org/10.4028/www.scientific.net/msf.636-637.1036.

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Ni-Mo and Ni+Mo coatings were prepared by electrodeposition under the galvanostatic conditions, in such a manner that the coatings contain the same quantity of molybdenum. The electrochemical activity of these coatings was studied in the process of hydrogen evolution reaction (HER) from 5 M KOH solution using steady-state polarization and electrochemical impedance spectroscopy (EIS) methods. Basing on the results of EIS measurements, the rate constants of the HER as well as the surface roughness factors were determined. It was found that Ni+Mo composite coating is characterized by enhanced electrochemical activity towards hydrogen evolution as compared with Ni-Mo alloy coating. Improvement of the electrocatalytic performance of Ni+Mo composite coating could be attributed to the increase in its real surface area as well as to the catalytic effect in points of contact of molybdenum and nickel matrix. Thus obtained composite coating may be useful in application as electrode materials for the hydrogen evolution reaction.

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Yan, Rui, Hang Wu, S. K. Yu, Shi Ning Ma, and Bin Shi Xu. "Application of EIS and SEM to Study the Corrosion Behaviors of Organic Coatings/Substrate System." Key Engineering Materials 373-374 (March 2008): 556–59. http://dx.doi.org/10.4028/www.scientific.net/kem.373-374.556.

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Electrochemical corrosion behaviors of two common-used ship coatings——epoxy aluminum coating, chloride rubber iron red coating and their composite coatings immersed in 3.5%NaCl solution were investigated using electrochemical impedance spectroscopy combined with open circuit potential measurements and SEM micrograph analysis. Potential-time result indicates that the free corrosion potential of these three coatings with immersion time are more positive than that of metal substrate, which can serve as barrier layer to protect metal substrate from corrosion. During the course of immersion, increasingly negative shift potentials with time reveal the growth of electrochemical area of anode and corrosion takes place continuously. EIS shows that corrosive species can penetrate into coatings and reach the coating/substrate interface promptly, causing the decrease of its shielding role and the beginning of electrochemical corrosion. SEM micrographs suggest that coatings were compact and continuous compared with obviously coarse and loose after corrosion, indicating the penetration of corrosive species destroys cross linkage of coatings. Composite coatings present better protection performance, displaying the effect of “1+1>2” remarkably.

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Bratkov, Iliya V., Tatiana F. Yudina, Aleksey G. Melnikov, and Artyem V. Bratkov. "PRODUCTION AND PROPERTIES OF COMPOSITE ELECTROCHEMICAL COATINGS WITH ELECTROCHEMICALLY DISPERSED GRAPHENE BASED ON NICKEL MATRIX." IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENII KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA 63, no. 8 (June 24, 2020): 90–95. http://dx.doi.org/10.6060/ivkkt.20206308.6221.

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In this work, the effect of addition of colloidal solutions of electrochemical exfoliated graphene (EEG) to the Watts bath on the process of obtaining composite coatings based on a nickel matrix was studied. It was found that the introduction of nanoparticle additives has a significant effect on the value of cathodic overvoltage during electro reduction of Ni2+. The strongest inhibition of the cathode process takes place with the introduction of 0.2 g/l of additives investigated. Further increase in the concentration of nanoparticles in the bath reduces the effect. The inhibition of the cathodic reduction of Ni2+ is associated with the adsorption of graphene nanoparticles on the active faces of growing nickel crystallites and the blocking of the accessible surface for Ni2+ reduction. Due to the increase in cathodic polarization during the deposition of the composite coating, the crystallites of the deposited nickel decrease in size and the texture of the crystal structure of the coating changes. According to energy dispersive spectroscopy data, carbon has been included in the composite coating. The carbon content in the coating increases with increasing concentration of nanoparticles in the working electrolyte. The inclusion of negatively charged nanoparticles of electrochemically dispersed graphene in the resulting precipitate becomes possible due to adsorption of Ni2+ and recharging of graphene nanoparticles. It was found that the optimal concentration of electrochemically dispersed graphene in the working electrolyte is 0.1-0.2 g/l. At a given nanoparticle content in the working bath, the porosity and roughness of the coatings decreases. The Tafel polarization curves for composite coating samples obtained in a 0.5M NaCl solution showed that the inclusion of graphene nanoparticles in the resulting coating leads to a shift of the corrosion potential to the negative area. With an increase in the carbon content in the coating, the shift in corrosion potentials increases, and the value of corrosion currents increases. For samples of composite coatings obtained at an EEG additive concentration of 0.1 g/l, a slight improvement in the protective properties is noted, which is associated with a decrease in the porosity of the coatings.

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Hosseinzadeh, Majid, Abdol Hamid Jafari, Rouhollah Mousavi, and Mojtaba Esmailzadeh. "Microstructure and corrosion resistance of Ni/Cr3C2-NiCr composite coating." Anti-Corrosion Methods and Materials 66, no. 4 (July 1, 2019): 471–78. http://dx.doi.org/10.1108/acmm-02-2019-2079.

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Purpose In this study, electrochemical deposition method which have cheaper equipment than thermal spraying methods and is available for the production of composite coatings were used. Design/methodology/approach Composite coatings were electrodeposited from a Watts's bath solution in which the suspended Cr3C2-NiCr particles were dispersed in the bath solution during deposition. Potentiodynamic polarization and electrochemical impedance spectroscopy techniques have been used to evaluate the corrosion resistance of the composite coating in the 3.5 Wt.% NaCl solution. Findings It was found that the submicron Cr3C2-NiCr particles distributed uniformly in the coating and depend on the current density of deposition, different amount of particles can be incorporated in the coating. The results showed that the corrosion resistance of the Ni/ Cr3C2-NiCr composite coatings is more comparable to the pure nickel coating. Originality/value Production of Ni-base composite coating from an electrolytic bath containing Cr3C2-NiCr particles is possible via electrodeposition.

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Cui, Shi Hai, Hong Tao Tang, Jian Yu Li, and Jian Min Han. "Corrosion Protection of a SiCp/ZL101 Composites by Using Plasma Electrolytic Oxidation Method." Advanced Materials Research 79-82 (August 2009): 1071–74. http://dx.doi.org/10.4028/www.scientific.net/amr.79-82.1071.

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A dense ceramic coatings with a thickness of 95μm was fabricated on a SiCp/ZL101 aluminum composites by using a plasma electrolytic oxidation(PEO) method. The XRD analysis showed that the PEO coating was mainly composed of α-Al2O3 γ-Al2O3 and mullite.The corrosion resistance of the PEO coatings and SiCp/ZL101 aluminum composites was estimated by the immersion test, salt spray test and electrochemical test. All the test results showed that the corrosion resistance of the composite was improved by the existence of the ceramic coating.

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Yuan, Xue Tao, Zhi Qiang Hua, Lei Wang, Dong Bai Sun, and Song Lin Chen. "Effect of Nano-Al₂O₃ Particles on the NiP/nano-Al₂O₃ Coatings’ Properties." Applied Mechanics and Materials 66-68 (July 2011): 1668–75. http://dx.doi.org/10.4028/www.scientific.net/amm.66-68.1668.

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Composite coatings were prepared using electroless nickel bath containing different concentrations of Al2O3nano-particles. The analyses of coating compositions, carried out by EDS, showed that there is marginal difference between phosphorus contents of NiP and NiP/nano-Al2O3deposits. The structure of the coatings was examined by scanning electron microscopy (SEM), and X-ray diffraction (XRD). It has been found that the co-deposition of nano-Al2O3particles with Ni disturbs the NiP coating’s regular surface structure and increases its surface roughness. DC and AC electrochemical tests were carried out on such coatings in a 3.5wt.% solution of NaCl in order to evaluate their corrosion resistance. The potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) tests both showed that, the corrosion resistance of NiP-Al2O3coatings firstly increases and then decreases when Al2O3concentration in electroless bath is increasing, but the corrosion resistance of NiP-Al2O3composite coating is better than that of amorphous NiP coating.

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Mashtalyar, Dmitry V., Sergey V. Gnedenkov, Sergey L. Sinebryukhov, and Igor M. Imshinetsky. "Electrophoretic Composite Coatings on Magnesium Alloys." Solid State Phenomena 245 (October 2015): 97–102. http://dx.doi.org/10.4028/www.scientific.net/ssp.245.97.

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Investigation results of the composite coatings obtained on MA8 magnesium alloy by plasma electrolytic oxidation (PEO) and post-treated by electrophoretic deposition of superdispersed polytetrafluoroethylene (SPTFE) are presented. Comprehensive research of electrochemical and mechanical properties of the obtained polymer-containing coatings on the magnesium alloy has been performed. It has been established that composite coatings to decrease the corrosion current density by three orders of magnitude (down to Ic = 2.0×10-10 A/cm2) and the wear by two orders of magnitude (down to 1.2×10-6 mm3/(N·m)), as compared to the basic PEO-coating.

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Kasach, Aliaksandr A., Dzmitry S. Kharytonau, Andrei V. Paspelau, Jacek Ryl, Denis S. Sergievich, Ivan M. Zharskii, and Irina I. Kurilo. "Effect of TiO2 Concentration on Microstructure and Properties of Composite Cu–Sn–TiO2 Coatings Obtained by Electrodeposition." Materials 14, no. 20 (October 18, 2021): 6179. http://dx.doi.org/10.3390/ma14206179.

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In this work, Cu–Sn–TiO2 composite coatings were electrochemically obtained from a sulfate bath containing 0–10 g/L of TiO2 nanoparticles. The effect of TiO2 particles on kinetics of cathodic electrodeposition has been studied by linear sweep voltammetry and chronopotentiometry. As compared to the Cu–Sn alloy, the Cu–Sn–TiO2 composite coatings show rougher surfaces with TiO2 agglomerates embedded in the metal matrix. The highest average amount of included TiO2 is 1.7 wt.%, in the case of the bath containing 5 g/L thereof. Composite coatings showed significantly improved antibacterial properties towards E. coli ATCC 8739 bacteria as compared to the Cu–Sn coatings of the same composition. Such improvement has been connected with the corrosion resistance of the composites studied by linear polarization and electrochemical impedance spectroscopy. In the bacterial media and 3% NaCl solutions, Cu–Sn–TiO2 composite coatings have lower corrosion resistance as compared to Cu–Sn alloys, which is caused by the nonuniformity of the surface.

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Nadaraia, Konstantine V., Sergey V. Gnedenkov, Sergey L. Sinebryukhov, and Dmitry V. Mashtalyar. "Protective Coatings Formed by PEO and Fluorine-Containing Compound." Defect and Diffusion Forum 386 (September 2018): 343–48. http://dx.doi.org/10.4028/www.scientific.net/ddf.386.343.

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Composite coatings have been obtained by plasma electrolytic oxidation method and subsequent treatment with fluorine-containing compound: suspension of superdispersed polytetrafluoroethylene. A method of formation of the protective coating by dipping into the suspension of organofluorine compound with subsequent heat treatment has been developed. The surface morphology of samples, their electrochemical and tribological properties, as well as wettability have been studied. Formed composite coatings reduce the corrosion current density and wear more than two orders of magnitude in comparison with the base PEO-coating. Additionally, composite layers have hydrophobic properties: for polymer-containing coatings the value of contact angle attains to 143±2°.

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Degtyar, Liudmila, Irina Zhukova, and Anastasia Kuts. "Electrodeposition kinetics and surface morphology of Ni-B-UDD composite coating." E3S Web of Conferences 273 (2021): 04015. http://dx.doi.org/10.1051/e3sconf/202127304015.

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The article presents the results of kinetic investigates of electrodeposition of a composite electrochemical coating based on a nickel-boron alloy. Current efficiency, polarization potentiodynamic researches had shown the joint participation in the electrodeposition process of finely dispersed compounds of nickel hydroxides, poorly soluble nickel and boron compounds present in the electrolyte or formed during electrolysis, and ultradispersed diamond introduced into the electrolyte. Comparison of 2D and 3D scans of the surfaces of the formed coatings confirmed the leveling effect of additives, as well as sparingly soluble nickel and boron compounds on the structure of coatings. The proposed composite electrochemical coatings can be used instead of chrome coatings when restoring parts and units of agricultural machinery.

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Yang, Zhang, Wang, Wang, Chen, Wei, and Xie. "Effect of Graphene Oxide Concentration in Electrolyte on Corrosion Behavior of Electrodeposited Zn–Electrochemical Reduction Graphene Composite Coatings." Coatings 9, no. 11 (November 14, 2019): 758. http://dx.doi.org/10.3390/coatings9110758.

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Pure Zn and Zn–ERGO composite coatings were prepared by direct current electrodeposition on 304 stainless steel. Samples were characterized by X-ray diffraction (XRD), scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM/EDS), and laser Raman spectroscopy (Raman). Results obtained have shown that the concentration of GO sheets in zinc sulfate electrolyte has an important effect on the preferred crystal orientation and the surface morphology of Zn–ERGO composite coatings. A study of the corrosion behavior of the coatings by Tafel polarization and electrochemical impedance spectroscopic (EIS) methods leads to the conclusion that the Zn-1.0 g/L ERGO composite coating possesses the best corrosion resistance compared to the pure Zn coating and other composite coatings in this study.

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Lu, Er Lin, Yan Chen, and Sheng Lu. "Corrosion Resistance of Plasma Sprayed AT13 Composite Ceramic Coating on Mg." Key Engineering Materials 575-576 (September 2013): 142–46. http://dx.doi.org/10.4028/www.scientific.net/kem.575-576.142.

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NiCoCrAlY/AT13 composite coating was prepared by plasma spraying technology on AZ91D substrate and sealed with three different methods. The corrosion resistances of the composite ceramic coatings with and without sealing were evaluated by immersion and electrochemical tests The results show that NiCoCrAlY/AT13 composite ceramic coating represents better corrosion property than single AT13 ceramic coating. The corrosion resistances of NiCoCrAlY/AT13 composite coatings with sealing are superior to that of unsealing coating. Among three sealed coatings, both coatings sealed with paraffin and varnish exhibit better corrosion resistance with corrosion rate of 0.130 g/(m2·h), 0.204 g/(m2·h), and Icorrof 1.754E-7 (A·cm-2), 9.493E-8 (A·cm-2) respectively, while the coating with epoxy resin sealing is relatively the worst one with corrosion rate of 0.744 g/(m2·h) and Icorrof 1.650E-7 (A·cm-2).

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Tseluikin, V. N. "Composite electrochemical coatings: Preparation, structure, properties." Protection of Metals and Physical Chemistry of Surfaces 45, no. 3 (May 2009): 312–26. http://dx.doi.org/10.1134/s2070205109030083.

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Xu, Hao, Haijun Hu, Hongmei Wang, Yongjun Li, and Yun Li. "Corrosion resistance of graphene/waterborne epoxy composite coatings in CO 2 -satarated NaCl solution." Royal Society Open Science 7, no. 5 (May 2020): 191943. http://dx.doi.org/10.1098/rsos.191943.

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This study investigated the corrosion resistance of graphene/waterborne epoxy composite coatings in CO 2 -satarated NaCl solution. The coatings were prepared by dispersing graphene in waterborne epoxy with the addition of carboxymethylcellulose sodium. The structure and composition of the coatings were characterized by scanning electron microscopy, transmission electron microscopy, Fourier-transform infrared and Raman spectroscopies. The corrosion resistance of the composite coatings was investigated by potentiodynamic polarization measurements and electrochemical impedance spectroscopy. Composite coatings with more uniform surfaces and far fewer defects than blank waterborne epoxy coatings were obtained on 1020 steel. The 0.5 wt% graphene/waterborne epoxy composite coating exhibited a much lower corrosion rate and provided better water resistance properties and long-term protection than those of the blank epoxy coating in CO 2 -satarated NaCl solution.

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Ying, Lixia, Yunlong Wu, Chongyang Nie, Chunxi Wu, and Guixiang Wang. "Improvement of the Tribological Properties and Corrosion Resistance of Epoxy–PTFE Composite Coating by Nanoparticle Modification." Coatings 11, no. 1 (December 24, 2020): 10. http://dx.doi.org/10.3390/coatings11010010.

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In order to meet the requirements of high corrosion resistance, wear resistance, and self-lubrication of composite coatings for marine applications, epoxy matrix composite coatings containing PTFE and TiO2 nanoparticles were prepared on the steel substrate. With silane coupling agent KH570 (CH2=C(CH3)COOC3H6Si(OCH3)3), titanium dioxide nanoparticles were modified, and organic functional groups were grafted on their surface to improve their dispersion and interface compatibility in the epoxy matrix. Then, the section morphology, tribological, and anticorrosion properties of prepared coatings, including pure epoxy, epoxy–PTFE, and the composite coating with unmodified and modified TiO2, respectively, were fully characterized by scanning electron microscopy, friction–abrasion testing machine, and an electrochemical workstation. The analytical results show that the modified TiO2 nanoparticles are able to improve the epoxy–PTFE composite coating’s mechanical properties of epoxy–PTFE composite coating including section toughness, hardness, and binding force. With the synergistic action of the friction reduction of PTFE and dispersion enhancement of TiO2 nanoparticles, the dry friction coefficient decreases by more than 73%. Simultaneously, modified titanium dioxide will not have much influence on the water contact angles of the coating. A larger water contact angle and uniform and compact microstructure make the composite coating incorporated modified TiO2 nanoparticles show excellent anti-corrosion ability, which has the minimum corrosion current density of 1.688 × 10−7 A·cm−2.

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He, Luying, Xin Shen, Yang Yao, and Hui Li. "A facial in-situ approach to synthesize Ti2Nb10O29@PANI core-shell microspheres for high performance lithium ion battery anodes." Materials Express 11, no. 5 (May 1, 2021): 749–57. http://dx.doi.org/10.1166/mex.2021.1964.

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Polyaniline (PANI) wrapped Ti2Nb10O29 (TNO) micro-spherical composites were successfully synthesized via a solvothermal approach combined with a facial post in-situ polymerization method. Effects of different amounts of the PANI coatings on the composite microspheres’ electrochemical properties were studied in detail. Results showed that the electrochemical performance of TNO@PANI anodes with 5 wt% PANI is the optimum among all the samples, giving capacity values as high as 272 mAh/g (1 C) and 190.1 mAh/g (20 C), respectively. Moreover, the electrochemical impedance measurements exhibited that 5 wt% TNO@PANI composite electrode material possess a weaker charge transfer resistance. This indicates that an appropriate amount of polyaniline coating can effectively improve the electronic conductivity of TNO microspheres and subsequently the electrochemical properties. In this work, we have demonstrated that 3D TNO@PANI composite microspheres not only deliver a higher initial Columbic efficiency but also can serve as next-generation lithium-ion battery electrode material with enhanced rate performance.

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Srikomol, S., P. Janetaisong, Y. Boonyongmaneerat, and R. Techapiesancharoenkij. "Morphology and Hardness of Electrochemically-Codeposited Ti-Dispersed Ni-Matrix Composite Coatings/ Morfologia I Twardość Elektrochemicznie Współosadzonych Powłok Kompozytowych Ni-Ti." Archives of Metallurgy and Materials 59, no. 4 (December 1, 2014): 1287–92. http://dx.doi.org/10.2478/amm-2014-0220.

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Abstract The effects of current density and Ti particle loading in a plating bath on the morphology and hardness of Ni-Ti composite coatings via an electrochemical-codeposition process were investigated. The Ti-reinforced Ni-matrix composite coatings were codeposited on copper substrates using a Ni-ion electrolytic solution stably suspended with -45 micron Ti particles. Within the current studied range, the coatings’ Ti contents are in the range between 46 and 62 at.%. The morphology appeared to vary with current density. Structures of the Ni-Ti composite coatings produced under low current density conditions revealed denser structures, which is in contrast to the more porous structures noted in the coatings produced under high current density. An initial increase of current density from 100 to 150 mA/cm2 also tends to raise Ti coating content. The reinforcement of Ti particles in the coatings also increased their hardness, which is attributed to the possible role of the embedded Ti particles in hindering matrix deformation. The effect of Ti loading on the coating’s Ti contents was not significant under conditions used in the present study

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CHENG, Qian, Haiyan CHEN, Yue HOU, Li FAN, Lihua DONG, and Yansheng YIN. "Wear and Corrosion Properties of Plasma Transferred Arc Ni-based Coatings Reinforced with NbC Particles." Materials Science 27, no. 3 (August 23, 2021): 294–301. http://dx.doi.org/10.5755/j02.ms.24211.

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The wear and corrosion resistance of Ni-based niobium carbide (NbC) coatings were investigated via scanning electron microscopy, energy dispersive spectrometry, particle size analysis, X-ray diffraction, electrochemical polarization, electrochemicl impedance spectroscopy, digital microhardness testing and wear testing. The results showed that the substrate was mainly composed of a γ-Cr (Fe) solid solution, and the composite coating was composed of FeNi, NbC, and Ni. In addition, the hardness of the coating increased gradually with increasing NbC content. The optimal corrosion resistance and wear resistance of the coating were realized at an NbC content of 20%.

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Wang, Zexin, Fei Ye, Liangyu Chen, Weigang Lv, Zhengyi Zhang, Qianhao Zang, Jinhua Peng, Lei Sun, and Sheng Lu. "Preparation and Degradation Characteristics of MAO/APS Composite Bio-Coating in Simulated Body Fluid." Coatings 11, no. 6 (May 31, 2021): 667. http://dx.doi.org/10.3390/coatings11060667.

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In this work, ZK60 magnesium alloy was employed as a substrate material to produce ceramic coatings, containing Ca and P, by micro-arc oxidation (MAO). Atmospheric plasma spraying (APS) was used to prepare the hydroxyapatite layer (HA) on the MAO coating to obtain a composite coating for better biological activity. The coatings were examined by various means including an X-ray diffractometer, a scanning electron microscope and an energy spectrometer. Meanwhile, an electrochemical examination, immersion test and tensile test were used to evaluate the in vitro performance of the composite coatings. The results showed that the composite coating has a better corrosion resistance. In addition, this work proposed a degradation model of the composite coating in the simulated body fluid immersion test. This model explains the degradation process of the MAO/APS coating in SBF.

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Arunima, S. R. "Electrochemical Characterization of Different Layers of Composite Incorporated Hot-Dip Zinc Coating." Asian Journal of Chemistry 32, no. 6 (2020): 1370–78. http://dx.doi.org/10.14233/ajchem.2020.22592.

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The present study beneficially explores nano TiO2 incorporated hot-dip zinc coatings for the enhanced corrosion protection of steel. Various electrochemical analyses such as open circuit potential (OCP), electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization studies were adopted to evaluate the enhanced galvanic performance and the stability of nano TiO2 composite incorporated coatings. The low corrosion current density and high polarization resistance of tuned composition of TiO2 incorporated hot-dip zinc coatings confirm its enhanced galvanic and corrosion resistant properties. The enhanced performance of TiO2 incorporated zinc coating was attributed to the combined effect of barrier and sacrificial behaviours.

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Zhang, Xuefei, Yuan Zhang, and Matthew Z. Yates. "Hydroxyapatite Nanocrystal Deposited Titanium Dioxide Nanotubes Loaded with Antibiotics for Combining Biocompatibility and Antibacterial Properties." MRS Advances 3, no. 30 (2018): 1703–9. http://dx.doi.org/10.1557/adv.2018.114.

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ABSTRACTHydroxyapatite (HA)/nanotubular titanium dioxide (TiO2) composite coatings loaded with antibiotics were developed to combine biocompatibility and antibacterial property. TiO2 nanotubes were first fabricated on Ti plates using anodization techniques. Then HA nanocrystals were synthesized on the TiO2 nanotubes by electrochemical deposition, followed by loading of a model drug compound, streptomycin. The streptomycin release profile of the composite coating was investigated. Bacterial tests demonstrate that the streptomycin-loaded composite coatings were highly effective in inhibiting bacterial growth. Simulated body fluid (SBF) experiments indicated that the composite coatings possessed good osseointegration capability.

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Caprì, Angela, Luigi Calabrese, Lucio Bonaccorsi, and Edoardo Proverbio. "Corrosion Resistance of Cerium Based Silane-Zeolite Coatings on AA6061 Alloy." Solid State Phenomena 227 (January 2015): 163–66. http://dx.doi.org/10.4028/www.scientific.net/ssp.227.163.

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In the present work we analyzed the anti-corrosive properties, on AA6061, of sol-gel silane-zeolite hybrid coatings doped with cerium nitrate ions as inhibitor. Three different types of composite coatings were prepared by using cerium doped zeolite and/or silane matrix. For each type, four formulations, varying the zeolite amount (in the range 60-90% wt), were tested. All composite coating evidenced a high homogeneity and good adhesion performances. Cerium addiction in the coating formulation did not compromise the hydrophobic properties of the coating. Furthermore the addition of the cerium ions improved the anti-corrosion properties of the composite films inducing a significant stability of the electrochemical behavior.

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Luo, Chuansheng. "Electrochemical corrosion behavior of Ni-P, AlCrN and Ni-P-AlCrN multilayer composite coatings used on grounding grids." Advances in Engineering Technology Research 1, no. 1 (May 18, 2022): 11. http://dx.doi.org/10.56028/aetr.1.1.11.

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In this work, single NiP alloy, we use cathodic arc ion plating and electroless plating, AlCrN and NiP-AlCrN multilayer composite coatings were sedimented from the teeth outwards Q235 carbon steel. It is surface appearances of the coating that were inspected by using scanning electron microscope method (SEM) and the crystal structure, which was researched by the diffraction of X-ray (XRD). The electrochemical corrosion behaviors were evaluated by electrochemical polarization tests with electrochemical impedance spectrum (EIS). The results of EIS displayed that the impedance increased in the order Q235＜AlCrN coating＜NiP alloy＜NiP-AlCrN composite coating. The corroded surfaces of coated samples were covered by some pitting while the surface of Q235 was totally destroyed.

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Belhamra, Nadjette, Abd Raouf Boulebtina, Khadidja Belassadi, Abdelouahed Chala, and Malika Diafi. "Effect of Doping of Nanoparticles on the Properties of Zn-Ni Composite Coatings." Diffusion Foundations 18 (September 2018): 19–26. http://dx.doi.org/10.4028/www.scientific.net/df.18.19.

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The purpose of this paper was to investigate the effect of Al2O3 and TiO2 nanoparticles contents on structural proporties, microhardness and corrosion resistance of Zn-Ni alloy coationg. Zn-Ni, Zn-Ni-Al2O3 and Zn-Ni-TiO2 composite coatings were electrodeposited on steel substrate by direct current in sulphate bath.The structure of the coatings was studied by X-ray diffration and by scaning electron miroscopy. The results showed the appearance of Ni5Zn21 phases and that the incrorporation of Al2O3 and TiO2 in the Zn-Ni coating refined the crystal grain size.The corrosion performance of coating in the 0.6M NaCl as a corrisive solution was investigated by potentiodynamic polarization and electrochemical impedance spectroscopy EIS methods. It was found that the incorporation of nanoparticules in Zn-Ni alloy coating have better corrosion resistance and the values of Rct and Zw increase, while the values of Cdl decrease with increasing of nanoparticules.

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Popczyk, Magdalena, Julian Kubisztal, Bożena Łosiewicz, and A. Budniok. "Production and Electrochemical Characterization of Nickel Based Composite Coatings Containing Chromium Group Metal and Silicon Powders." Solid State Phenomena 228 (March 2015): 219–24. http://dx.doi.org/10.4028/www.scientific.net/ssp.228.219.

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The Ni+Cr+Si, Ni+Mo+Si and Ni+W+Si composite coatings were obtained by electrodeposition of crystalline nickel from an electrolyte containing suspension of suitable metallic and non-metallic components (Cr, Mo, W and Si). These coatings were obtained galvanostatically at the current density of jdep = -0.100 A cm-2 and at the temperature of 338 K. Chemical composition of the coatings was determined by energy dispersive spectroscopy (EDS). The electrochemical activity of these electrocatalysts was studied in the process of hydrogen evolution reaction (HER) in 5 M KOH solution using steady-state polarization and electrochemical impedance spectroscopy (EIS) methods. The kinetic parameters of the HER on particular electrode materials were determined. It was found that Ni+Mo+Si composite coatings are characterized by enhanced electrochemical activity towards the HER as compared with Ni+W+Si and Ni+Cr+Si coatings due to the presence of Mo and increase in electrochemically active surface area.

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Patil, Viresh G., Sakthivel Kandaiah, and B. Somasundaram. "Electrochemical Corrosion Behavior of Heat-Treated HVOF Coatings on ASTM SA213-T22 Steel." Corrosion 78, no. 2 (December 28, 2021): 198–212. http://dx.doi.org/10.5006/3957.

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Herein the electrochemical corrosion behavior of pre- and post-heat-treated composite coatings of NiCrMoFeCoAl-30%SiO2 and NiCrMoFeCoAl-30%Cr2O3 on ASTM SA213-T22 boiler tube steel by a high-velocity oxygen fuel (HVOF) spraying technique are reported. The samples were subjected to hot molten salt (Na2SO4–60%V2O5) corrosion environment in a tubular furnace at 700°C under thermocyclic conditions. The microscopic, structural, and electrochemical investigations of post-heat-treated specimens reveal NiCrMoFeCoAl-30%Cr2O3 composite HVOF coating exhibits a superior corrosion resistance compared to NiCrMoFeCoAl-30%SiO2 composite coating and bare ASTM SA213-T22 steel boiler tube steel in neutral electrolyte. The room-temperature potentiodynamic and impedance investigations of heat-treated samples suggest high interfacial charge transfer resistance for HVOF coatings over a wide anodic potential window. This could be ascribed to the protective nature of the chromium-oxide-containing coatings on high-temperature treatment. AC impedance analysis reveals NiCrMoFeCoAl-30%Cr2O3 coating exhibits very high resistive behavior with very high charge transfer resistance, in the order of 106 Ω higher than the NiCrMoFeCoAl-30%SiO2 coating and uncoated ASTM SA213-T22 steel boiler tube steel. Furthermore, the high-temperature-induced formation of metal chromates/chromites along with the presence of Cr2O3 provides good resistance toward corrosion.

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Kordijazi, Amir. "Electrochemical Characteristics of an Optimized Ni-P-Zn Electroless Composite Coating." Advanced Materials Research 1043 (October 2014): 124–28. http://dx.doi.org/10.4028/www.scientific.net/amr.1043.124.

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An optimized electroless solution was used to deposit the Ni-P-Zn composite coating. Potentiodynamic polarization test, salt spray technique and electrochemical impedance spectroscopy were utilized to study electrochemical characteristics of the as-deposited coating. All results demonstrate an excellent corrosion resistance of the as-deposited layer. Corrosion current density of the coating was compared to some similar coatings reported in other papers to study reasons of its high corrosion resistance. It was proved that the high corrosion protection of the coating is due to the optimization of P and Zn contents in the coating composition.

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Praveen, B. M., and T. V. Venkatesha. "Electrodeposition and Corrosion Resistance Properties of Zn-Ni/TiO2Nano composite Coatings." International Journal of Electrochemistry 2011 (2011): 1–4. http://dx.doi.org/10.4061/2011/261407.

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Nano sized TiO2particles were prepared by sol-gel method. TiO2nano particles were dispersed in zinc-nickel sulphate electrolyte and thin film of Zn-Ni-TiO2composite was generated by electrodeposition on mild steel plates. The effect of TiO2on the corrosion behavior and hardness of the composite coatings was investigated. The film was tested for its corrosion resistance property using electrochemical, weight loss, and salt spray methods. The paper revealed higher resistance of composite coating to corrosion. Microhardness of the composite coating was determined. Scanning electron microscope images and X-ray diffraction patterns of coating revealed its fine-grain nature. Average crystalline size of the composite coating was calculated. The anticorrosion mechanism of the composite coating was also discussed.

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Fan, Li, Hai Yan Chen, Hai Liang Du, Yue Hou, and Qian Cheng. "Corrosion Resistance of Nickel-Based Composite Coatings Reinforced by Spherical Tungsten Carbide." Materials Science Forum 993 (May 2020): 1075–85. http://dx.doi.org/10.4028/www.scientific.net/msf.993.1075.

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Nickel-based composite coatings reinforced by spherical tungsten carbide were deposited on 42CrMo alloy steel using plasma transfer arc welding (PTAW) process. Their electrochemical corrosion properties in NaCl solution under atmospheric and high pressure were studied by polarization curve, electrochemical impedance spectroscopy. The corrosion and erosion resistance of the coatings were also investigated by salt spray corrosion and erosion corrosion tests. The results show that the self-corrosion potential of the composite coatings increased with the increase of tungsten carbide content, and the Cr element in Ni60 sample formed a stable and compact passivation film. Compared with corrosion at atmospheric pressure, the adsorption and penetration of Cl- on the coating surface enhanced due to the increase of Cl- activity under pressure, thereby to weaken the corrosion resistance. The Samples that passivated in salt spray environment, cannot completely hinder the corrosion of the coating, just only to slow down the corrosion. This study can provide theoretical basis for deep-sea oil drilling and production engineering equipment.

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García-Pérez, César A., Carmina Menchaca-Campos, Miguel A. García-Sánchez, and Jorge Uruchurtu. "Electrochemical Capacitive Properties of Ny/PP/GO Electro-spun Composite Coating on Stainless Steel in Acid Media." European Journal of Engineering and Technology Research 7, no. 2 (March 30, 2022): 81–86. http://dx.doi.org/10.24018/ejeng.2022.7.2.2775.

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Composite materials were manufactured to obtain singular properties to be used as in electrochemical driven energy systems. An electrochemical evaluation was performed on electro-spun nylon 6,6 fibers (Ny), with different concentrations of tetra-para-amino-phenyl porphyrin (PP) and graphene oxide (GO) composite coating over stainless steel (SS), immersed in 1M H2SO4 aggressive sulfuric acid solution. Different film coatings behavior was obtained and compared using electrochemical impedance spectroscopy (EIS). Also, cyclic voltametry (CV) were performed on nylon/PP/GO composite coating system at different scan rates, and over film covered carbon cloth. For the electro-spun composite coating on stainless steel EIS, lower electro-spinning times present higher impedance, hence some corrosion protection. For greater electro-spinning times, larger capacitance values were observed. These were possibly due to thicker coating or mass transport adsorption-diffusion process through the composite film, respectively. For the composite coating, porphyrins, and graphene oxide interaction present ionic conductivity, reducing the impedance and promoting proton formation, property which could be used in charge storage systems.

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Liang, Cheng Hao, Shu Sen Wang, Nai Bao Huang, and Bo Wu. "Preparation of Hydroxyapatite Composite Coatings with Interlayer of TiO₂ and its Corrosion Behaviors." Applied Mechanics and Materials 548-549 (April 2014): 72–76. http://dx.doi.org/10.4028/www.scientific.net/amm.548-549.72.

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Hydroxyapatite (HAP) composite coatings with interlayer of TiO2 on Ti6Al4V alloy were prepared by microarc oxidation and electrochemical potentiostatic method. Platelet adhesion test and electrochemical behaviors of the HAP coatings were investigated in platelet-rich plasma, Ringer's solution, Tyrode's solution and human blood at 37°C. The HAP coating was characterized by scanning electron microscope (SEM), X-ray diffraction (XRD). TiO2 coating has round ostioles on the surface with the element of O, Na, Al, Si and Ti. The HAP coating has sheet-like, column-like and batten-like crystal with the Ca/P 1.6689. The biocompatibility of HAP coating was better than the initial coating. The results indicated that the HAP coating had better characters of anticorrosion and biocompatibility.

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Punith Kumar, M. K., Mahander Pratap Singh, and Chandan Srivastava. "Electrochemical behavior of Zn–graphene composite coatings." RSC Advances 5, no. 32 (2015): 25603–8. http://dx.doi.org/10.1039/c5ra02898a.

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Jiang, Ji Bo, Wei Dong Liu, Lei Zhang, Qing Dong Zhong, Yi Wang, and Qiong Yu Zhou. "Electrodeposition and Hardness and Corrosion Resistance Propertie of Ni/Nano-B₄C Composite Coatings." Advanced Materials Research 399-401 (November 2011): 2055–60. http://dx.doi.org/10.4028/www.scientific.net/amr.399-401.2055.

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Ni–B4C composite coatings on carbon steel substrates with various contents of B4C nano-particulates were prepared by electrodeposition in Ni plating bath containing B4C nano-particulates. Microhardness, Scanning Electron Microscopy (SEM), Tafel polarization and Electrochemical Impedance Spectroscopy (EIS) measurements were used to compare pure nickel coatings and Ni–B4C composite coatings. Pure Ni coating microhardness is lower than that of Ni–B4C coatings and the microhardness of the composite coatings increases with the increase of the content of B4C nano-particulates. The effects of various contents of B4C nano-particulates on the corrosion resistance were investigated and it was found that the best anti–corrosion property of Ni–B4C composite coatings is at 6 g/L B4C in the bath formulation.

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Łosiewicz, Bożena, Iwona Napłoszek, Magdalena Popczyk, and A. Budniok. "Characterization of Composite Coatings Obtained by Electrodeposition." Solid State Phenomena 228 (March 2015): 49–57. http://dx.doi.org/10.4028/www.scientific.net/ssp.228.49.

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The work concerns the literature review which unambiguously shows that the composite coatings which apart from thed-electron metal powder contain another component of the composite, i.e. thep-electron metal powder, have not been obtained so far. This kind of qualitative composition of the coating enables selective extraction of thep-electron metal from the nickel matrix of the composite, as well as – after heat treatment – results in the formation of the mixture of intermetallic phases with the hitherto unknown activity in the electrochemical processes.

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JIANG, JIBO, HAOTIAN CHEN, LIYING ZHU, YAOXIN SUN, WEI QIAN, HUALIN LIN, and SHENG HAN. "MICROSTRUCTURE AND ELECTROCHEMICAL PROPERTIES OF Ni–B/GO ULTRASONIC-ASSISTED COMPOSITE COATINGS." Surface Review and Letters 26, no. 10 (November 14, 2019): 1950080. http://dx.doi.org/10.1142/s0218625x1950080x.

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Graphene oxide (GO) sheet and ultrasonic field (UF) were successfully employed to produce Ni–B/GO and UF–Ni–B/GO composite coatings on Q235 mild steel by electroless plating. The composite coatings’ structure and surface morphology were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). Results showed that GO was successfully co-deposited in the Ni–B alloy. Moreover, UF–Ni–B/GO composite coatings have smoother surface and thicker cross-section than others. The microhardness and corrosion resistance of the sample coatings were determined using Vickers hardness tests, Tafel electrochemical tests and electrochemical impedance measurements (EIS) in 3.5[Formula: see text]wt.% NaCl solution to receive the effect of GO and ultrasonic. The findings indicated that UF–Ni–B/GO exhibited optimum hardness (856[Formula: see text]HV) and enhanced corrosion resistance (6.38 [Formula: see text][Formula: see text] over the Ni–B and Ni–B/GO coatings. Due to these interesting properties of the coating, it could be used as a protective material in the automotive and aerospace industries for parts of machines that were manipulated in high temperature and corrosive environments.

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Zhao, Qi, Zhang, Li, and Li. "Electrochemical Impedance Spectroscopy Investigation on the Corrosive Behaviour of Waterborne Silicate Micaceous Iron Oxide Coatings in Seawater." Coatings 9, no. 7 (June 28, 2019): 415. http://dx.doi.org/10.3390/coatings9070415.

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The anticorrosive composite coatings based on waterborne silicate were prepared to replace existing solvent-based coatings suitable for ships. A series of composite coatings were prepared by adding zinc powder and micaceous iron oxide to the waterborne silicate resin. The adhesion, pencil hardness and impact resistance of the coatings were investigated and corrosion performance in seawater is characterized by electrochemical impedance spectroscopy (EIS). The results show that coatings have excellent adhesion and impact resistance and their pencil hardness can reach up to 4H. During the immersion of composite coatings in seawater for 8 h, only one time constant appears in the Bode plot, coating capacitance (Qc) gradually increases but dispersion coefficient (n) and coating resistance (Rc) gradually decrease. The breakpoint frequency formula was deduced, considering the dispersion effect. With the increase of micaceous iron oxide, the fluctuation of breakpoint frequency with immersion time is weakened. It can be used to evaluate the corrosion resistance of inorganic anticorrosive coatings in seawater. In addition, different penetration models of corrosive media were proposed for the coatings with low or high content of micaceous iron oxide.

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Sun, Wan Chang, Ming Feng Tan, Jian Hua Lu, Lei Zhang, and Quan Zhou. "Corrosion and Oxidation Resistance of Electroless Ni-P-Al₂O₃ Composite Coatings on Carbon Steel." Applied Mechanics and Materials 34-35 (October 2010): 831–35. http://dx.doi.org/10.4028/www.scientific.net/amm.34-35.831.

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Electroless Ni-P and Ni-P-Al2O3 composite coatings on low carbon steel (Q235) sheets were prepared by adopting optimum plating process. The cross-section morphology and structure as well as the phase transformation of the composite coatings were studied by scanning electron microscopy(SEM), X-ray diffraction(XRD). It was shown that the Al2O3 particles homogeneously dispersed in the entire Ni-P film matrix, and the structure of Ni-P-Al2O3 composite coatings as deposited was amorphous. The corrosion behaviors were evaluated by electrochemical tests. The experimental results indicated that the corrosion resistance of Ni-P-Al2O3 coatings was superior to Ni-P coatings due to the effect of Al2O3 particles. In addition, the oxidation resistance test, which was carried out by using oxidation weight method, showed that ternary Ni-P-Al2O3 composite coating had a better oxidation resistance than Ni-P coating.

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Xu, Ting, Ye Fa Tan, and Bin Liu. "Tribological Properties of Ni-Base Alloy Coatings Reinforced by SiC Particles." Advanced Materials Research 538-541 (June 2012): 181–85. http://dx.doi.org/10.4028/www.scientific.net/amr.538-541.181.

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Ni-Co/SiC composite coatings embedded with different sizes of micron-Sic particles were prepared on the surfure of 45 carbon steel through electrochemical deposition. The effects of size of SiC particles on the microstructure, the hardness and tribological properties of the composite coatings were investigated. The results show that the decrease of the size may increase the hardness, make microstructure closer and greatly improve their wear resistance. The Ni-Co/SiC(W7) coating exhibit better integrated properties, its hardness was HV505, 20 percent higher than Ni-Co alloy coating, and its wear rate was only 1/5 of the Ni-Co/SiC(W40) coating. The wear mechanisms of the coatings are mainly plastic deformation with slight adhesive wear.

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Li, Ouyang, Guirong Yang, Wenming Song, Dawen Gao, and Xianming Sun. "Microstructure and polarization behavior of Ni/WC+GO (graphene oxide) composite cladding fusion coating." International Journal of Materials Research 112, no. 4 (March 19, 2021): 308–20. http://dx.doi.org/10.1515/ijmr-2020-7765.

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Abstract Ni/WC/graphene oxide (GO) composite cladding fusion coatings were fabricated through the vacuum cladding technique on a medium carbon structure steel (45# steel) substrate whose carbon content was 0.45 ± 0.03%. The microstructural characteristics, phase composition, and electrochemical polarization characteristics of the composite cladding fusion coatings were analyzed with scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, and the electrochemical workstation CHI660E. Results show that the microstructure was compact and was micro-crack free, and without inclusions or other defects. It was comprised of four micro-zones, namely, the composite, transition, diffusion fusion, and diffusion-affected zones with thicknesses of approximately 4 mm, 1 mm, 20 μm, and 250 μm, respectively. The main phases of the composite coating were γ-Ni solid solution, WC, Cr7C3, Ni2.9Cr0.7Fe0.36, Cr23C6, Ni3Fe, Ni3Si, Ni3B, W2C, and C. The self-corrosion potential of the composite coatings had increased by 0.3269 V compared with that of the substrate, and the corrosion current density of the composite coatings had decreased by nearly two orders of magnitude. The Ni-based solid solution region with relatively high C and Cr contents was difficult to dissolve.

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Dou, Wenwen, Wen Li, Yuchen Cai, Mengyao Dong, Xiaojing Wang, Jincheng Fan, Juying Zhou, et al. "Improved Corrosion Resistance and Increased Hardness of Copper Substrates from Cu-Ni/Ni-P Composite Coatings." MRS Advances 5, no. 40-41 (2020): 2129–37. http://dx.doi.org/10.1557/adv.2020.226.

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ABSTRACTTo improve the corrosion resistance and to increase the hardness of copper substrate in marine environment, the Cu-Ni/Ni-P composite coatings were prepared on the copper substrate using the galvanostatic electrolytic deposition method. The deposition current densities were explored to find the optimized deposition conditions for forming the composite coatings. Corrosion resistance properties were analyzed using the polarization curves and electrochemical impedance spectroscopy (EIS). Considering the corrosion resistance and hardness, the −20 mA/cm2 was selected to deposit Cu-Ni coatings on copper substrate and the −30 mA/cm2 was selected to deposit Ni-P coating on the Cu-Ni layer. The Cu-Ni/Ni-P composite coatings not only exhibited superior corrosion resistance compared to single Cu-Ni coating in 3.5 wt.% NaCl solution, but also showed much better mechanical properties than single Cu-Ni coating.

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Journal articles on the topic 'Composite electrochemical coatings'

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