Microstructure and Corrosion Study of Porous Mg-Zn-Ca Alloy in Simulated Body Fluid (TW 4)

Magnesium alloys had been considered as promising biomedical devices due to their biocompatibility and biodegradability. In this present work, microstructure and corrosion properties of Mg-Zn-Ca-CaCO3 porous magnesium alloy were investigated. Porous metals were fabricated through powder metallurgy process with CaCO3 addition as a foaming agent. CaCO3 content was varied (1, 5, and 10 persenwt) followed by sintering process in 650°C in Argon atmosphere for 10 and 15 hours. The microstructure of the resulted alloys was analyzed by scanning electron microscopy (JEOL, JSM-6390A Japan) equipped with energy dispersive spectrometry data (EDS). Further, to examine corrosion properties, electrochemical test were conducted using G750 Gamry Instrument in accordance with ASTM standard G5-94 in simulated body fluid (Hank’s solution). As it was predicted, increasing content of foaming agent was in line with the increasing of pore formation. Moreover, foaming agent addition were seems related to the tendency of intermetallic phase formation in the grain boundary. The electrochemical testing indicated corrosion rate would increase along with the increasing of foaming agent. Highest corrosion resistance was given by Mg-Zn-Ca-1CaCO3-10 hours sintering with potential corrosion of -1.59 VSCE and corrosion rate of 1.01 mmpy. From the microstructure after electrochemical testing, it was revealed that higher susceptibility to corrosion occurred in the grain boundary which related to the precipitation of intermetallic phases. MRS-ID Meeting 2016