Development of Biodegradable Mg-Zn Alloys by Tailoring The Extrusion Temperature

Abstract

In this study, we developed a biodegradable Mg-Zn alloy with both good strength and elongation. Various Mg alloys have been developed over the years because of their excellent properties, including biodegradability. However, their limited elongation and rapid corrosion limit their widespread use. In this study, a Mg-3 wt% Zn alloy was developed, and its mechanical and corrosion properties were evaluated. The cast and solution-heat-treated Mg-3 wt% Zn alloys were extruded at temperatures from 350 to 180 °C, and excellent mechanical strength and elongation were achieved after extrusion at 200 and 180 °C, respectively. However, the alloy extruded at 180 °C exhibited rapid corrosion during in vitro evaluation owing to the precipitation of a second phase during extrusion. The enhanced performance of the Mg-3 wt% Zn alloys was attributed to grain refinement, which not only increased the mechanical properties by grain boundary strengthening and twinning but also increased the corrosion resistance as a result of the rapid passivation kinetics.

Keywords: Mg-Zn alloy, twins, biodegradable alloy, mechanical property enhancement, Extrusion, grain boundary strengthening