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 alpha-Ti transforms into beta-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 mu A/cm(2) 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. (C) 2013 Elsevier Ltd. All rights reserved.