Mg-based bulk metallic glasses: A review of recent developments

Metallic biomaterials have been widely used in the field of medical implants for replacement purposes and/or for regeneration of tissue. Metals such as stainless steel (316 L), cobalt-chromium alloys and titanium alloys (Ti-6Al-4 V) are widely used as metallic implants today. However, they often exhibit unsatisfactory results such as stress shielding, the release of toxic ions and are often permanent and invasive – where a second surgery is required to remove the implant once the bone is fully healed. Magnesium as a biomaterial have attracted much attention recently due to its excellent biocompatibility, similar mechanical properties to bone and biodegradability. Unlike other metals and bio ceramics, the ability for magnesium alloys to undergo biodegradation eliminates the requirement for a second surgery to remove the implant. Additionally, the degradation of magnesium releases Mg 2+ ions, which stimulates metabolism as they are a cofactor in numerous numbers of enzymes. Despite the advantages of magnesium alloys, the rapid degradation of magnesium proved to be challenging as the implant is unable to retain its structural integrity sufficiently enough to act as an implant. To improve the corrosion resistance of magnesium alloys, researchers have been working on the synthesis and characterization of Mg-based bulk metallic glasses, which can significantly improve the corrosion resistance of Mg-based alloys. This paper is a comprehensive review that compiles, analyzes and critically discusses the recent literature on the latest understanding of the processing, mechanical and biological characteristics of Mg-based bulk metallic glasses.