Influence of Hot Rolling on Ti-Nb-Zr(-Ta) Multiprincipal Alloys for Biomedical Application

With increasing life expectancy, revision surgeries have become more frequent in implanted people. This is due to the biological and biomechanical incompatibility that generates, among others, problems such as stress shielding. This works aims to analyze the influence of the hot rolling process (HR sample) on the microstructure and, consequently, the properties of beta-Ti multiprincipal alloys: Ti-27Nb-39Zr (39Zr), Ti-30Nb-50Zr (50Zr), and Ti-20Nb-30Zr-13Ta (30Zr) (wt. %.) (equimassic and with high content of beta-stabilizer elements). All samples were subjected to characterization through X-ray diffraction (XRD) to determine the phases present, and optical microscopy (OM) and scanning electronic microscopy (SEM) were realized to characterize the microstructure and confirm the phases obtained through XRD. Before hot rolling, only the beta phase was identified, but in the HR condition, the alpha and beta phases were identified. Consequently, it did not observe significant changes in microhardness for all alloys, while the elastic modulus was observed with a reduction of 23% for 39Zr, 46% for 40Zr, and 13% for 30Zr. The hot rolling processing was confirmed to be a helpful route to reduce the elastic modulus for beta Ti multiprincipal alloys opening perspectives for applying such alloys as metallic implant materials.