Effects of Sn content on the microstructure, mechanical properties and biocompatibility of Ti–Nb–Sn/hydroxyapatite biocomposites synthesized by powder metallurgy

In this work Ti–35Nb–xSn/15hydroxyapatite (HA, x = 2.5, 5, 10 wt.%) bulk biocomposites were fabricated by high energy mechanical milling (HEMM) and pulse current activated sintering (PCAS). The microstructure and characteristics of Ti–35Nb–xSn/15HA milled powders and bulk composites sintered from powders milled for 12 h were studied. The results indicate that α-Ti transforms into β-Ti completely in 12 h milled Ti–35Nb–2.5Sn/15HA powders due to the solid solution of Nb into Ti lattice. The ultrafine grains are obtained in the bulk Ti–35Nb–2.5Sn/15HA composites. All bulk Ti–35Nb–xSn/15HA composites have high compression strength and low elastic modulus (21–23 GPa). The corrosion current density of bulk Ti–35Nb–2.5Sn/15HA composites is about 0.18 μA/cm2 in Hank’s solution. Cell culture results reveal that MC-3T3 osteoblast cells have good growing and spreading ability on the surface of bulk Ti–35Nb–xSn/15HA composites. Cell viability for bulk Ti–35Nb–2.5Sn/15HA composite is 0.4 times higher than that for CP Ti. The results demonstrate that bulk Ti–35Nb–xSn/15HA composites are promising biomaterials.