Biodegradable Alloys: The glass window of opportunities

Crystalline metallic alloys aims to provide the desired key properties for biomedical applications constitute an important group of biomedical materials. Magnesium alloys, are also witnessing increased demand for such applications. A number of alloys that are used for orthopaedics and coronary stents were adapted from existing alloys used in engineering. Metallic glasses are prepared by fast-cooling molten alloys to below their glass-transition temperature thereby avoiding crystallization altogether. The developed window allows the tuning of the Zn concentration to levels sufficiently high to partially passivate the surface, in a physiological environment changes to protect the surface and reduces hydrogen production to acceptable levels. The alteration of corrosion behavior is impossible in crystalline alloys as at such Zn concentrations, would evolve into crystallites of several intermetallic compounds with very different Zn contents, fixed by equilibrium solubility limits.