Preparation and characterization of metastable ?-type titanium alloys with favorable properties for orthopedic applications

Titanium (Ti)-based alloys with good mechanical properties are highly desirable for bone implants to achieve long-term clinical success. As non-toxic alloying elements, zirconium (Zr) and molybdenum (Mo) have been employed to improve the mechanical properties of Ti-based alloys. In this work, a series of Ti-Zr -Mo alloys, including Ti-18Zr, Ti-13Mo, and Ti-18Zr-13Mo were prepared and compared for potential or-thopedic applications for the first time. The phase composition, microstructure, mechanical properties, corrosion resistance, biocompatibility, and osteointegration performance were systemically investigated. It is found that Ti-18Zr displayed an acicular alpha ' phase, whereas Ti-13Mo and Ti-18Zr-13Mo exhibited a me-tastable beta phase. Compared with commercially pure Ti (CP-Ti), the prepared Ti-Zr-Mo alloys possessed a higher compressive yield strength and a greater microhardness, because of the solid solution and phase precipitation strengthening of Zr and Mo elements. Furthermore, Ti-18Zr-13Mo and Ti-13Mo demonstrated better corrosion resistance than that of CP-Ti, while Ti-18Zr exhibited an inferior result. The cytocompat-ibility and osteointegration of prepared alloys were similar to those of CP-Ti. Taken together, the Ti-Zr-Mo alloys investigated in this study present a promising alternative to CP-Ti for orthopedic applications, among which the metastable beta-type alloy Ti-18Zr-13Mo is most attractive. Moreover, an appropriate Mo content enhances the mechanical and corrosion resistance properties of Ti-based alloys, whereas a high Zr content may pose an adverse influence on the corrosion resistance, which provides valuable insights into the design and further optimizing of new Ti-Zr-Mo alloys for future biomedical applications.(c) 2023 Elsevier B.V. All rights reserved.