Microstructure of Biodegradable Zn-Fe Alloys and Mechanical and Corrosion Properties

This article reports microstructural characterization of as-cast and as-extruded Zn-Fe alloys and their mechanical and corrosion properties. Specifically, 1 wt.%, 2 wt.% and 3 wt.% Fe was added into the Zn matrix to form respective Zn-Fe alloys using casting and indirect hot extrusion processes. As the Fe content increased within the range of 1–3 wt.%, the mechanical properties of as-cast and as-extruded Zn-Fe alloys improved. The as-extruded Zn-Fe alloys showed superior mechanical properties of hardness, ultimate tensile strength (UTS) and elongation to failure (EL) to the as-cast Zn-Fe alloys of the same composition. Specifically, the UTS for as-extruded Zn-Fe alloys was 138–170 MPa, whereas the UTS for as-cast Zn-Fe alloys was 89–125 MPa. The corrosion properties of the as-extruded Zn-Fe alloys were investigated using the electrochemical and immersion methods. The corrosion rate of the as-extruded Zn-Fe alloys ranged from 0.015 mm/year to 0.210 mm/year.