Corrosion barriers induced by nano-heterogeneous structure in a biodegradable Mg Zn-based metal

Due to its excellent biocompatibility and biodegradability, Mg has received widespread attention in biomaterials as implants and even bio-batteries. However, the poor corrosion resistance makes it difficult to meet the growing demand for implant materials. This study developed a biodegradable nano-heterogeneous Mg(48 wt%)Zn(52 wt%)-based metal (NHMZ) comprising nanocrystalline matrix phase Mg51Zn20 and nanoscale MgZn2 precipitates. The unique microstructure of NHMZ enhances its corrosion resistance. The spherical aberration-corrected transmission electron microscope (AC-TEM) and precession electron diffraction (PED) characterized the microstructures. The corrosion rate of NHMZ is about 0.21 mm y−1 after soaking for 4 weeks, approximately 58 % of high pure Mg. In addition, the anode discharge of NHMZ is more stable than Mg, indicating it has great potential in biological batteries. This work hopes to broaden the development direction of biodegradable metallic materials and break through the performance limitation of current biodegradable Mg alloys.