Microstructure and corrosion study of porous Mg–Zn–Ca alloy in simulated body fluid

AbstractMagnesium alloys had been considered as promising biomedical devices due to theirbiocompatibility and biodegradability. In this present work, microstructure and corrosion propertiesof Mg–Zn–Ca–CaCO3 porous magnesium alloy were examined. Porous metals were fabricatedthrough powder metallurgy process with CaCO3 addition as a foaming agent. CaCO3 content wasvaried (1, 5, and 10 persenwt) followed by sintering process in 650 °C in Argon atmosphere for 10 and15 h. The microstructure of the resulted alloys was analyzed by scanning electron microscopy (SEM)equipped with energy dispersive spectrometry data (EDS). Further, to examine corrosion properties,electrochemical test were conducted using G750 Gamry Instrument in accordance with ASTMstandard G5-94 in simulated body fluid (Hank’s solution). As it was predicted, increasing contentof foaming agent was in line with the increasing of pore formation. The electrochemical testingindicated corrosion rate would increase along with the increasing of foaming agent. The porousMg–Zn–Ca alloy which has more porosity and connecting area will corrode much faster because itcan transport the solution containing chloride ion which accelerated the chemical reaction. Highestcorrosion resistance was given by Mg–Zn–Ca–1CaCO3-10 h sintering with potential corrosionof −1.59 VSCE and corrosion rate of 1.01 mmpy. From the microstructure after electrochemicaltesting, it was revealed that volcano shaped structure and crack would occur after exposure to Hank’ssolution Mater. Res. Express 4 (2017) 034006