Fabrication of Ti-Nb-Ag alloy via powder metallurgy for biomedical applications

Ti and some of its alloys are widely used as orthopedic implants. In the present study, Ti-26Nb-5Ag alloys were prepared by mechanical alloying followed by vacuum furnace sintering or spark plasma sintering (SPS). The microstructure and mechanical properties of the Ti-Nb-Ag alloys were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM) combined with energy-dispersive X-ray spectroscopy (EDX), compressive and micro-hardness tests. The effect of different sintering methods on the microstructure and properties of Ti-Nb-Ag alloy was discussed. The results showed that the titanium alloy sintered by vacuum furnace exhibited a microstructure consisting of a, b and a small amount of a 00 martensite phase; whilst the SPS sintered alloy exhibited a microstructure consisting of a, b and a small amount of a 00 martensite phase, as well as a nanostructured Ag homogeneously distributed at the boundaries of the b phases. The Ti-Nb-Ag alloy sintered by SPS possessed fracture strength nearly 3 times of the alloy sintered by vacuum furnace.