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Investigation on corrosion and wear resistance of MgO‐Al 2 O 3 composite coating prepared by plasma electrolytic oxidation
Author(s) -
Liu Xintong,
Wang Dongdong,
Wu Yekang,
Yang Zhong,
Li Dalong,
Shen Dejiu
Publication year - 2020
Publication title -
international journal of applied ceramic technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.4
H-Index - 57
eISSN - 1744-7402
pISSN - 1546-542X
DOI - 10.1111/ijac.13458
Subject(s) - materials science , dielectric spectroscopy , corrosion , coating , scanning electron microscope , plasma electrolytic oxidation , microstructure , electrolyte , alloy , energy dispersive x ray spectroscopy , polarization (electrochemistry) , metallurgy , composite number , ceramic , electrochemistry , chemical engineering , composite material , electrode , chemistry , engineering
Ceramic coatings were prepared on 6061 Al alloy in a mixed electrolyte with/without MgO powders at different treatment durations. The results of energy dispersive spectroscopy (EDS) and X‐ray diffraction (XRD) showed that MgO powder was incorporated into the coatings, and Mg species gradually aggregated into coating inside as prolonging the oxidation time. Scanning electron microscopy (SEM) showed that MgO additive had a certain effect on the microstructures and coating thickness. The corrosion behavior tests evaluated by potentiodynamic polarization tests and electrochemical impedance spectroscopy (EIS) in 3.5 wt% NaCl solution suggested that at the same treatment time, the addition of MgO powders can improve the corrosion resistance of the coating, and the Mg‐rich layer can affect the corrosion resistance of the coating. The tests of mechanical properties showed that the addition of MgO powders improved the stability and hardness of the coating.