Microstructure, mechanical behavior and bioactivity properties of 45S5 reinforced magnesium-zinc matrix composites produced by powder metallurgy

This study investigates the fabrication and characterization of magnesium-zinc composites reinforced with varying contents (0, 2.5, 5, and 10 wt.%) of bioactive glass (BG) using powder metallurgy. The objective is to enhance the mechanical and biological performance of magnesium-based biomaterials for potential orthopedic implant applications. The composites were sintered at 580°C and characterized in terms of density, porosity, microstructure, and in vitro bioactivity through immersion in simulated body fluid (SBF). The results show that increasing BG content influences density, porosity, and microstructural features. Density increased up to 5 wt.% BG and decreased at 10 wt.%, while porosity showed a gradual increase. SEM analysis revealed increased microstructural heterogeneity at higher BG contents. Apatite layer formation was observed on the composite surfaces after SBF immersion, suggesting potential surface bioactivity. These findings indicate that BG reinforcement can effectively tailor the physical and biological properties of Mg-Zn composites, offering promise for the development of biodegradable orthopedic implants.