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Corrosion behavior of ZnNiAl 2 O 3 nanocomposite coatings obtained by electrodeposition from alkaline electrolytes
Author(s) -
Blejan D.,
Muresan L. M.
Publication year - 2013
Publication title -
materials and corrosion
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.487
H-Index - 55
eISSN - 1521-4176
pISSN - 0947-5117
DOI - 10.1002/maco.201206522
Subject(s) - dielectric spectroscopy , corrosion , nanocomposite , materials science , electrolyte , polarization (electrochemistry) , electrochemistry , carbon steel , open circuit voltage , nanoparticle , chemical engineering , metallurgy , nuclear chemistry , analytical chemistry (journal) , chemistry , composite material , nanotechnology , electrode , physics , voltage , quantum mechanics , chromatography , engineering
The aim of this work was to investigate the anti‐corrosive properties of nanocomposite ZnNi coatings containing Al 2 O 3 nanoparticles, prepared from alkaline commercial electrolytes (pH 13), (PERFORMA 280.5, COVENTYA S.A.S, France), by electrodeposition on carbon steel (OL37). The corrosion resistance of the coatings prepared with different concentrations of Al 2 O 3 (5, 10, and 15 g/L) was evaluated in 0.2 g/L Na 2 SO 4 solution (pH 5) by open circuit potential (OCP) measurements, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS) techniques. The results of electrochemical measurements were corroborated with those obtained by using X‐ray diffraction analysis. The obtained results show that the introduction of Al 2 O 3 nanoparticles in the plating bath generally brings an increase in corrosion resistance of ZnNi layers and put in evidence the existence of an optimal Al 2 O 3 concentration. Under the examined conditions, the optimal concentration determined from polarization measurements was proven to be 5 g/L Al 2 O 3 . The highest value of the polarization resistance, R p , obtained from impedance measurements corresponds also to ZnNi with 5 g/L Al 2 O 3 , which is in agreement with the results obtained from polarization and XRD measurements.