The Influence of Rolling Reduction on the Mechanical, Corrosion, Osteogenic, and Antibacterial Properties of Zn–Mg Alloys

Biodegradable zinc (Zn) alloys are promising biodegradable metals owing to their appropriate in vivo degradation rate. To address the problem of low mechanical properties of pure Zn, magnesium (Mg) is added into Zn to develop Zn-0.5Mg alloys which are rolled subsequently. Microstructural analysis reveals a grain size distribution in the Zn alloy with a 50% reduction comprising both fine grains (3.14 μm) and larger grains (>20 μm), the latter containing numerous dislocations. With increasing reduction to 80%, the deformed grains undergo transformation into finer grains through dynamic recrystallization (DRX). Although ultimate tensile strengths remain similar between two Zn alloys, the as-rolled Zn-0.5Mg alloy with a 50% reduction exhibits a higher work-hardening rate and lower yield strength. The influence of the reduction on the corrosion rate of the as-rolled Zn-0.5Mg alloys is minimal. With increasing reduction, fine grains promote corrosion rates by accelerating grain boundary corrosion. Both Zn alloys demonstrate favorable cell viability and osteogenic properties, as verified by alkaline phosphatase staining results. Moreover, superior antibacterial properties to <i>Escherichia coli</i> and <i>Staphylococcus aureus</i> are demonstrated in as-rolled Zn-Mg alloys. These findings contribute to the development of high-strength Zn alloys with elevated work-hardening rates, essential for the security of implants during plastic deformation.