%0 journal article
%@ 0925-8388
%A Tiyyagura, H.R., Petovar, B., Finsgar, M., Willumeit-Roemer, R., Luthringer, B.J.C., Mohan, M.K., Kokol, V.

%D 2019
%J Journal of Alloys and Compounds

%P 980-987 
%R doi:10.1016/j.jallcom.2018.09.330
%T Degradation behaviour of Mg-4Ag and Mg-5Gd alloys under in-vitro conditions and different time-frames
%U https://doi.org/10.1016/j.jallcom.2018.09.330
 
%X The Electrochemical Impedance Spectroscopy (EIS) measurements, being performed for up to 3 days, revealed that the corrosion of all three alloys are under a kinetic-controlled mechanism, among which only pure Mg and Mg-4Ag show a repassivation ability in this time-frame. However, the corrosion rates of binary alloys after 28 days of incubation reaching a value of around 0.33 mm/y and a release of 64 mg/L Mg2+ ions, that was accompanied by a pH change up to 8.3, an be lower compared to the pure Mg alloy (0.62 mm/y, 117 mg/L of Mg2+, pH of 9.0). While thick and homogenous layers of differently-shaped and chemically secondary-phased Mg(OH)2 products were identified on both binary alloys, MgO products and an apatite structure are formed on the pure Mg alloy surface. The Mg-4Ag alloy seems to be biomedically the most appropriate regarding the in-vitro degradation process.