In-vitro Corrosion-Induced Strength-Ductility Degradation in WE43 and ZX10 Magnesium Alloy Fine Wires for Biomedical Applications

With an increasing demand for biodegradable structural materials, magnesium (Mg) alloys stand out as promising candidates. Here, we investigate the corrosion-induced mechanical degradation of fine wires made from WE43 and ZX10 Mg alloys, evaluating their suitability for biomedical applications such as scaffolds, stents, and sutures. Both alloys exhibit distinct microstructural features that influence their corrosion and mechanical behavior. WE43 wires, characterized by neodymium-rich precipitates and elongated grains, showed significant axial pitting corrosion and a rapid decline in mechanical properties attributed to micro-galvanic corrosion and potential hydrogen embrittlement. In contrast, ZX10 wires, featuring coarser and heterogeneously distributed Mg ₂ Ca precipitates, demonstrated extensive localized pitting but retained higher ductility and toughness over extended exposure. Micro-CT analyses reveal that precipitate size, distribution, and volume fraction critically influence corrosion morphology and mechanical degradation. The findings emphasize the importance of tailoring alloy microstructures to enhance corrosion resistance and mechanical performance. While WE43's higher corrosion rates and more rapid property degradation limit its potential in applications with fine dimensions, ZX10's lower corrosion rate and higher mechanical resilience make it a more viable candidate. Future research should prioritize developing chemically homogeneous precipitates in ZX10 that are small and uniformly distributed.