Journal Articles
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Item Corrosion properties of ceria-based coating electrodeposited from alkaline bath on electrogalvanized steel(Journal of Applied Electrochemistry, 2021) Rouabhia, F; Hamlaoui, Y; Meroufel, A; Pedraza, FLong-term protectiveness of zinc coatings remains challenging where conversion surface pre-treatments are suggested such as the promising cerium oxide-based coatings. In the present work, the efect of acetic acid addition and of temperature of the bath on the ceria-based coatings produced by cathodic electrodeposition on electrogalvanized steel are investigated. The electrochemical, surface chemistry, and topographical properties are characterized and their corrosion performance is evalu ated in NaCl solution. The results show that the coatings prepared from equimolar mixture of cerium chloride and acetic acid at pH 8 and room temperature were less cracked, had a smaller grain size, and ofered a three-fold increase of the corrosion resistance when compared with those prepared in cerium chloride solution at pH 6. From X-ray difraction patterns, it seems that the deposits obtained at pH 8 are free from corrosion products. Moreover, the porosity of the coatings obtained at pH 8 increases with increasing the bath temperatures indicating that at high bath temperature the deposits become heterogeneous and do not cover the whole surface of the substrateItem Electrochemical investigation of ceria nanoparticles as a corrosion inhibitor for steel in alkaline medium(2023) Bourenane, N; Hamlaoui, Y; Pedraza, FThis work investigates the synthesis and the corrosion inhibitor efficiency ceria nanoparticles may exert on steel reinforcement in an alkaline solution of saturated Ca(OH)2 + 0.5 M CaCl2 up to 50°C. The corrosion mechanisms are thoroughly investigated by electrochemical and various characterization techniques. The electrochemical results show that ceria nanoparticles act as an anodic inhibitor and provide maximum inhibition efficiency (80%) at a concentration of 800 ppm. The resulting surface is smooth and free from corrosion products due to the formation of a physically adsorbed film according to the thermodynamic calculations.Item Corrosion protection mechanism of Ce3+/polyethylene glycol systems inhibitors for mild steel in sulfate solution(Materials and corrosion, 2023) boudellioua, H; Hamlaoui, Y; Pedraza, FIn the present paper, cerium nitrate salt was used as a green inhibitor to improve the corrosion resistance of mild steel in 0.1 M Na2SO4 solution. To increase the barrier effect and film stability of the protective layer, polyethylene glycol (PEG) was added. The corrosion tests were evaluated using d.c polarization techniques and electrochemical impedance spectros copy. The composition and morphology of the sample surface were characterized using Raman spectroscopy and MEB/EDS analysis. The resultsshow that the presence of PEG improved relatively the corrosion resistance of mild steel due to the removal of cracks, the pores blocking the formed film and the enhancement of adhesion and compactness of the cerium‐based film. Consequently, the protective film became more coherent on the steel surface. Furthermore, the potentiodynamic polarization indicated that the Ce3+/PEG system behaved as a mixed‐type inhibitor with the dominant effect of the cathodic part.