Study of Zn–Ag alloys prepared via powder metallurgy

Abstract Orthopaedic biomaterials require a balance between mechanical integrity and controlled degradation. Among biodegradable metals, magnesium-based alloys degrade too rapidly, leading to premature loss of mechanical support, whereas iron-based alloys exhibit slow degradation and high stiffness, which may limit their clinical applicability. In contrast, zinc-based materials offer a more favourable combination of moderate corrosion rate and mechanical properties closer to natural bone. However, the relatively low mechanical strength of pure zinc remains a critical limitation, highlighting the need for effective alloying and processing strategies. In this context, the incorporation of silver represents a promising approach to enhance both the mechanical strength and antibacterial performance of zinc. Despite this potential, the combined effect of composition and processing route, particularly cost-effective techniques such as powder metallurgy, on the structural and functional behaviour of Zn-Ag systems remains insufficiently understood. In this study, binary alloys Zn-xAg ( x = 2.0, 4.0, 6.0 wt% Ag) and pure Zn were prepared using powder metallurgy. The structure, corrosion behaviour, surface morphology, and wettability were evaluated. The highest corrosion rate of 0.353 mm year −1 was observed for the pure Zn sample. Atomic force microscopy revealed that the surface of pure zinc was the smoothest, while the roughness of Zn-Ag alloys increased with silver content. X-ray diffraction analysis confirmed the presence of intermetallic phases. Furthermore, contact angle measurements indicated slightly hydrophilic surfaces, which could promote cell adhesion. These findings demonstrate that Zn-Ag alloys processed via powder metallurgy represent a promising strategy for tailoring the mechanical and functional performance of zinc-based implants.