Preparing High Strength and Elongation of Biodegradable Zinc-Magnesium Alloys with Superior Antibacterial Properties and Biocompatibility

The extrusion-formed Zn-0.5Mg alloy got a improved elongation and tensile strength by the addition of Mn. The influence of Mn on the strength contribution was investigated by comparing the microstructures of the designed Zn-0.5Mg and Zn-0.5Mg-0.2Mn alloys. The deformed binary Zn-Mg alloy had a grain size of 9 mu m, and the grain size of the deformed ternary Zn-Mg-Mn alloy was 3 m. This result indicated that the extrusion-formed Zn-Mg-Mn alloy had a greater contribution to grain boundary strengthening than the extrusion-formed Zn-Mg alloy. Furthermore, the precipitates in the two alloys show significant differences in size, morphology, density, and variety. Precipitates in the Mn-containing Zn alloy showed a smaller size, higher density, and the ratio of length and diameter. The high elongation rate of the extrusion-formed Zn-Mg-Mn alloy was attributed to the fully fragmented Mg2Zn11 and deformable MnZn13 phases. In addition to enhancing its mechanical characteristics, the Zn-Mg-Mn alloy, as extruded, exhibits the same corrosion rates, antibacterial properties, and biocompatibility. These results are helpful in expanding the applications of Zn alloys in the orthopaedic field.