Properties of treated Ti-12Mo-25Nb alloy

The production of β-metastable Ti alloys combines essential properties for their application as biomaterials in the replacement of bone cells. Commercially, titanium implants are made from commercially pure titanium (CP Ti) or the Ti-6Al-4V (Ti64) alloy. However, the presence of cytotoxic chemical elements in the Ti64 alloy, such as Al and V, has motivated the development of new Ti alloys free from these elements, such as those in the Ti-Mo-Nb system. These new alloys combine low Young’s modulus, corrosion resistance in bodily fluids, good mechanical properties, and biocompatibility, and have been the focus of recent research. In this context, the present study aims to characterize the microstructure and evaluate the mechanical properties of the heat-treated Ti-12Mo-25Nb alloy (wt.%). The alloy was produced by arc melting using a non-consumable tungsten electrode in an inert argon atmosphere. Subsequently, the as-cast alloy was homogenized at 950 °C for 1 hour and water quenched. The microstructure was characterized by X-ray diffraction (XRD) and optical microscopy (OM), and the mechanical properties were evaluated through Vickers microhardness measurements and elastic modulus determined by the impulse excitation technique. The results indicated that the microstructure contained only the β-Ti (metastable) phase. The Vickers microhardness measurements were 210 ± 2 HV, and the elastic modulus was 74 GPa. Thus, the Ti-12Mo-25Nb alloy presented a hardness-to-modulus ratio (H/M) of 2.84, demonstrating great potential for biomedical applications.