Preparation, structural, microstructural, mechanical, and cytotoxic characterization of Ti-15Nb alloy for biomedical applications.

Titanium alloys are widely used in the biomedical field due to their excellent resistance to corrosion, high mechanical strength/density ratio, low elastic modulus, and good biocompatibility. Niobium is a β-stabilizer element that has the potential to decrease elastic modulus and possesses excellent corrosion resistance. In this article, Ti-15Nb alloy was prepared via arc-melting, with the aim of using it in biomedical applications to replace implants that fail due to mechanical incompatibility with human bone. This Ti-15Nb alloy was structurally, chemically, and microstructurally characterized. Its mechanical properties were analyzed via Vickers microhardness and elastic modulus measurements. The cytotoxicity of the alloy was evaluated via direct and indirect MTT tests. In the direct MTT test, the cells were grown on alloy and in the indirect test, Ti-15Nb alloy extracts were prepared (1 g/1 mL at 310 K for 48 hours). The results of chemical composition showed that the alloy produced has good quality and low content of gaseous impurities, such as oxygen and nitrogen. The obtained results for structure and microstructure indicated the presence of the martensite α' phase. The microhardness of the Ti-15Nb alloy is superior to that of cp-Ti due to solid solution hardening, and the alloy has a better elastic modulus as compared to pure titanium. Cytotoxic effects were not observed. The Ti-15Nb alloy shows good results of mechanical properties and does not show cytotoxic effects. In addition, morphological variations were not found in the cells and good cell adhesion in all the studied conditions was observed. In general, the alloy proposed in this article has satisfactory characteristics as a biomedical material.