%0 journal article
%@ 0257-8972
%A Jangde, A., Kumar, S., Blawert, C.

%D 2022
%J Surface and Coatings Technology

%P 128971 
%R doi:10.1016/j.surfcoat.2022.128971
%T Role of glycerine on formation & corrosion characteristic of PEO layer formed over Mg alloy in a high-concentrated mixed silicate-phosphate-based electrolyte
%U https://doi.org/10.1016/j.surfcoat.2022.128971
 
%X PEO coatings on AM50 magnesium alloy were synthesized under constant current mode exploiting high-concentrated mixed silicate-phosphate-based alkaline electrolyte with and without glycerine as an additive, i.e., gmix-PEO and bmix-PEO respectively. The development of PEO coatings was studied as a function of PEO treatment time for their microstructures, element compositions, phase compositions, and corrosion behaviour. For all the treatment times, gmix-PEO exhibited relatively smaller pores and lower coating thickness than bmix-PEO. The elemental composition of PEO coatings was independent of PEO processing time for both bmix-PEO and gmix-PEO. Throughout PEO processing the incorporation of Si was considerably higher than P into the synthesized coatings. MgO and Mg2SiO4 crystalline phase content was higher for gmix-PEO compared to bmix-PEO for all the treatment times studied. A complex amorphous oxide phase was observed from 4 min PEO treatment time for bmix-PEO while glycerine addition delayed the formation of the same. The study of electrochemical behaviour revealed improved corrosion performance of gmix-PEO particularly during initial immersion (up to 25 h) time for up to 4 min PEO treatment time than for bmix-PEO as glycerine addition leads to higher MgO and Mg2SiO4 phase content and thicker/compact inner barrier layer. For the final 8 min PEO processing time, bmix-PEO offered enhanced corrosion performance particularly due to its thicker coating compared to gmix-PEO.