Abstract
Ceramic coatings were fabricated on AZ91D Mg-alloy substrate by microarc oxidation in Na 2SiO 3–NaOH–Na 2EDTA electrolytes with and without C 3H 8O 3 addition. The effects of different concentrations of C 3H 8O 3 contained in the electrolyte on coatings thickness were investigated. The surface morphologies, RMS roughness, phase compositions and corrosion resistance property of the ceramic coatings were analyzed by scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD), and electrochemical corrosion test respectively. It is found that the addition of C 3H 8O 3 into silicate electrolyte leads to increase of the unit-area adsorptive capacity of the negative ions at anode–electrolyte interface and thus improves the compactness and corrosion resistance of the MAO coating. The coating thickness decreases gradually with the increase of concentrations of C 3H 8O 3 in the electrolyte. The oxide coating formed in base electrolyte containing 4 mL/L C 3H 8O 3 exhibits the best surface appearance, the lowest surface RMS roughness (174 nm) and highest corrosion resistance. In addition, both ceramic coatings treated in base electrolyte with and without C 3H 8O 3 are mainly composed of periclase MgO and forsterite Mg 2SiO 4 phase, but no diffraction peak of Mg phase is found in the patterns.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
