Fabrication of high strength, antibacterial and biocompatible Ti-5Mo-5Ag alloy for medical and surgical implant applications.

β-Titanium alloys have been widely used in medical and surgical implants. However, the present titanium alloys are facing challenges from implant-associated infections and the requirements for highly stressed applications. To overcome these problems, by taking advantage of the β-phase stabilizing element Mo and the antimicrobial element Ag, we fabricated bulk fine-grained Ti-5Mo-5Ag alloys by a combination of mechanical alloying and spark plasma sintering. The alloy sintered at 900 °C showed a network microstructure consisting of 89% β-phase with average grain size of 8.1 (± 3.2) μm as the matrix and 11% α-phase with micron/submicron-scale precipitates at the grain boundaries/triple junctions. Such network structure offered excellent mechanical properties with compressive yield strength of up to 1694 (± 8.4) MPa and fracture strain of 23%. In comparison with pure titanium, the fabricated Ti-5Mo-5Ag alloys also demonstrated enhanced corrosion resistance and exceptional antibacterial activity (with antibacterial rate up to ~95% against S. aureus). A combination of excellent mechanical properties, corrosion resistance and biological functions enables the fabricated Ti-5Mo-5Ag alloy a promising candidate for load-bearing implant applications.