Mg-Zn-Ca amorphous alloys for application as temporary implant: Effect of Zn content on the mechanical and corrosion properties

Abstract

In this paper, two Mg-Zn-Ca amorphous alloys were processed and their mechanical and corrosion properties were evaluated and compared. The first alloy was a new composition, Zn-rich, Mg60Zn34Ca6, designed thanks to a multifold approach involving two different criteria, topological instability, and electronic criteria. The second alloy, with less Zn content, was a well-known Mg73Zn23Ca4, used for the sake of comparison. Three kinds of rapidly solidified samples were processed for each composition: ribbons, wedge, and cylindrical samples. The new composition showed much better glass-forming ability and superior corrosion and mechanical properties than the Zn-poorer composition. The effect of Fe content, a typical contaminant in Mg-based alloys, was also evaluated. Electrochemical results in amorphous and in crystalline samples showed that increasing iron to certain amounts has no influence on the corrosion resistance of the investigated alloys.