An Insight towards the Design of a Ruthenium-Containing Biomaterial

Abstract

Ruthenium (Ru) is one of the platinum group metals (PGMs). These metals belong to the transition metals group of the periodic table. They have excellent properties such as high melting point and are inert with variety of substances, thus also called noble metals. Currently, Ru is the cheapest of the PGMs, thus it is readily available compared to other PGMs. Recently, incorporating PGMs in shape memory alloys (SMAs) has been extensively explored, with titanium-nickel (TiNi) used as a bench-mark material. TiRu is amongst the compounds that are currently explored for various potential applications. This compound has an ordered B2 (CsCl-type) crystal structure. It is hard and brittle, thus some shape memory (SM) properties are difficult to induce in this compound. However, due to Ru possessing some good biomedical properties such as biocompatibility, corrosion resistance, improved radiopacity and ultra-low magnetic susceptibility for MRI diagnostics, the mechanical properties of TiRu must be improved for biomedical applications. Since niobium (Nb) is known to be biocompatible and is usually studied in biomedical alloys, a systematic substitution of Ti with niobium (Nb) was performed in an effort to reduce the stiffness (Young’s modulus). This chapter gives an insight on the structural and mechanical properties of biocompatible Ru-rich alloy compositions.