Corrosion behavior and antibacterial performance of Zn–Mg composites with controllable degradation rate

Conventional methods have difficulty producing biodegradable Zn-Mg alloys with high Mg contents because excessive intermetallic formation can accelerate corrosion and result in poorly controlled degradation. This study employed low-temperature hot pressing (100°C, 249.60 MPa) to fabricate Zn-Mg composite materials free of intermetallic compounds, aiming for a controllable degradation rate. This work systematically examines the effect of Mg content on the microstructure, mechanical properties, and degradation behavior of Zn-Mg composites during the low-temperature hot pressing, while also evaluating their preliminary antibacterial performance. Microstructure analysis indicates that low-temperature hot pressing results in the physical compounding of Zn/Mg phases rather than alloying, with Zn particles exhibiting better plasticity than Mg particles. Microhardness decreases as Mg content increases, which may be attributable to the absence of intermetallic compounds. The fracture mode shifts from ductile to brittle with increasing Mg content. Mg content markedly affects the corrosion resistance of Zn-Mg composites: the corrosion current density of Zn-60Mg is approximately 42.95% higher than that of Zn-10Mg. Antibacterial testing against Staphylococcus aureus (S. aureus) shows that Zn-Mg composites exhibit antibacterial activity, with Zn-10Mg showing the strongest effect.