11. Niobium Biomaterials

Niobium is a particularly attractive metal for application as a biomaterial, due to the highly inert and unreactive nature of its surface. However, mechanical property limitations have restricted the use of the material in this field. This chapter initially reviews some of the fundamental aspects of niobium biocompatibility with a particular emphasis on surface technologies such as vapour deposition, sol-gel, anodizing and boronizing. Recent and ongoing activities aimed at improving bulk mechanical performance are also reviewed. These include approaches such as severe plastic deformation to refine grain structures and the development of new alloys. Where appropriate, data that demonstrates biocompatibility of these new niobium surfaces is also presented. Thus while niobium alloys have seen limited application to date, this chapter presents an overview showing the great potential for this material and the ongoing efforts in this regard.