Development and characterization of biodegradable Fe-based alloys

Iron and its alloys are currently evaluated for use as biodegradable materials for temporary medical implants. The concept of a metallic implant that degrades within the human body has become increasingly accepted in recent years. If the material degraded in the body while the tissue recovered implant removal would become obsolete. Fe is a promising candidate as a degradable implant material. This work develops a design strategy which takes into account electrochemical, microstructural and toxicological aspects. The aim is to find alloys whose performance is suitable for implant applications, in terms of both degradation rate and high strength and ductility. The austenitic high-Mn alloys developed in the study possess an impressive combination of high ductility, simultaneously high strength levels and a pronounced strain hardening response. Degradation properties were evaluated by means of immersion testing and electrochemical impedance spectroscopy in physiological media. In vitro cytocompatibility studies were performed by means of indirect cell tests using extracts from the alloys. The overall performance of the alloys developed and characterized in this study is very promising.