MICROSTRUCTURAL, MECHANICAL AND CORROSIVE EVALUATION OF THE Ti-6Al-4V ALLOY WITH ADDITION OF Nb OBTAINED BY ARC MELTING
Titanium alloys are advanced materials used in high demand applications, as they offer superior properties compared to common metals such as steel, aluminum, magnesium, among others. Its properties such as high resistance to oxidation in aggressive environments, high mechanical strength such as elastic modulus, resistance to fatigue and good biocompatibility make it attractive to the aeronautical, chemical, automotive, biomedical industries, among others. The Ti-6Al-4V alloy is the most common titanium alloy on the market because it has excellent mechanical and corrosive characteristics and its application is widely used in several industries, including the biomedical industry. Therefore, the present work aims to study the effect of adding Niobium which is a biocompatible element in different concentrations of 13%, 35% and 53% by weight to the Ti-6Al-4V alloy. The alloys were obtained by means of solidification in a mold, using an arc furnace with a controlled atmosphere of argon, equipped with a copper crucible and mould Subsequently, heat treatments were carried out, where the treatment temperature of each alloy was determined according to the niobium concentration. The microstructural characterization was performed by optical microscopy, scanning electron microscopy and X-ray diffraction. The mechanical characterization was performed using Vickers hardness and nanohardness measurements and compression tests at room temperature. In addition, electrochemical tests were carried out to verify the electrochemical behavior in a saline environment. The results indicated that with increasing niobium concentration, greater is the stabilization of the β phase, a residual phase in Ti-6Al-4V alloys. In addition, its mechanical properties such as hardness decreases with the increase of niobium, since the β phase is a less resistant phase than the α phase and the metastable phases α' and α''. For electrochemical tests, the samples showed a slight improvement in corrosion resistance with the addition of niobium.