Mg-Li-Based Alloys as Implant Materials

Abstract

This chapter is aimed at discussing the prospect of using novel magnesium-lithium-based alloys for temporary implantation. It discusses the challenges of implant materials and focuses on the design, characterization, and assessment of Mg-Li-Zn-Ca alloys. Biodegradable magnesium alloys have recently been the material of choice for the manufacture of implantable medical devices because they proffer efficacious solutions to temporary implantation. Magnesium-lithium-based alloys are a unique system of alloys that offer enhanced ductility and uniform degradation. The increase of lithium in the quaternary Mg-Li-Zn-Ca system resulted in phase transformation of the hcp crystal structure of magnesium to bcc, thus improving ductility. Lithium promoted the formation of a solid solution and a compact surface oxide that decreased corrosion kinetics in biological media. The alloys exhibited good biocompatibility, as evidenced by cell viability and metabolic activity when exposed to solutions retrieved from immersion tests. Furthermore, the improvement in mechanical properties and degradation properties of these alloys relative to other magnesium-based alloys provide an opportunity for wider adoption in the biomedical field.