PEO of AZ31 Mg Alloy: Effect of Electrolyte\nPhosphate Content and Current Density

0534789 - ÚFM 2021 RIV CH eng J - Journal Article
Hadzima, B. - Kajánek, D. - Jambor, Michal - Drábiková, J. - Březina, M. - Buhagiar, J. - Pastorková, J. - Jacková, M.
PEO of AZ31 Mg Alloy: Effect of Electrolyte
Phosphate Content and Current Density.
Metals. Roč. 10, č. 11 (2020), č. článku 1521. E-ISSN 2075-4701
Grant - others:AV ČR(CZ) StrategieAV21/5
Program: StrategieAV
Institutional support: RVO:68081723
Keywords : magnesium alloy * plasma electrolytic oxidation * corrosion
OECD category: Coating and films
Impact factor: 2.351, year: 2020
Method of publishing: Open access
https://www.mdpi.com/2075-4701/10/11/1521

In this work, the quality of coatings prepared by plasma electrolytic oxidation (PEO)
on an AZ31 magnesium alloy were evaluated. This was done by studying the effects of the
chemical composition of phosphate-based process electrolytes in combination with different applied
current densities on coating thickness, porosity, micro-cracking and corrosion resistance in 0.1 M
NaCl. Both processing parameters were studied in four different levels. Mid-term corrosion
resistance in 0.1 M NaCl was examined by electrochemical impedance spectroscopy and based
on this, corrosion mechanisms were hypothesized. Results of performed experiments showed
that the chosen processing parameters and electrolyte composition significantly influenced the
morphology and corrosion performance of the prepared PEO coatings. The PEO coating prepared in
an electrolyte with 12 g/L Na3PO4·12H2O and using an applied current density 0.05 A/cm2
reached
the highest value of polarization resistance. This was more than 11 times higher when compared to
the uncoated counterpart.
Permanent Link: http://hdl.handle.net/11104/0313017