A study of degradation behaviour and biocompatibility of Zn—Fe alloy prepared by electrodeposition

Zinc is a biodegradable metal, which exhibits more moderate biodegradability than magnesium and iron, so that it has great application potential in the field of biomedical materials. Alloying of zinc and iron may lead to producing a new type of implant material Zn—Fe alloy, which might be able to meet the requirements for a moderate degradation rate. However, due to the huge difference in the melting point between zinc and iron, the preparation of Zn—Fe alloy is quite challenging and hence rarely reported. In this study, we show that Zn—Fe alloys can be successfully prepared by electrodeposition technology. The microstructures, composition, degradation properties and biocompatibility of the Zn—Fe alloys were systematically studied. The results showed that the content of iron in the alloys ranged from 0 to 8 wt%, depending on the concentration of Fe ions and the current density. In the alloys, the major's phases were η, δ and Г₁, and they were mainly affected by the ion concentration in the electrolyte. In the in vitro immersion tests, the Zn—Fe alloy ZF2–1 showed the highest immersion corrosion rate, while ZF3–1 showed the highest electrochemical corrosion rate. Moreover, we found that the corrosion rates of the alloys were significantly higher than that of the pure Fe. In the in vivo experiments, we confirmed that the Zn—Fe alloy possessed good biocompatibility. These results demonstrate that the electrodeposition technology is a good method to prepare Zn—Fe alloys, and the Zn—Fe alloys prepared by this method are potentially promising materials for biomedical applications.