Effect of nano/micro-Ag compound particles on the bio-corrosion, antibacterial properties and cell biocompatibility of Ti-Ag alloys.

In this research, Ti-Ag alloys were prepared by powder metallurgy, casting and heat treatment method in order to investigate the effect of Ag compound particles on the bio-corrosion, the antibacterial property and the cell biocompatibility. Ti-Ag alloys with different sizes of Ag or Ag-compounds particles were successfully prepared: small amount of submicro-scale (100nm) Ti2Ag precipitates with solid solution state of Ag, large amount of nano-scale (20-30nm) Ti2Ag precipitates with small amount of solid solution state of Ag and micro-scale lamellar Ti2Ag phases, and complete solid solution state of Ag. The mechanical tests indicated that both nano/micro-scale Ti2Ag phases had a strong dispersion strengthening ability and Ag had a high solid solution strengthening ability. Electrochemical results shown the Ag content and the size of Ag particles had a limited influence on the bio-corrosion resistance although nano-scale Ti2Ag precipitates slightly improved corrosion resistance. It was demonstrated that the nano Ag compounds precipitates have a significant influence on the antibacterial properties of Ti-Ag alloys but no effect on the cell biocompatibility. It was thought that both Ag ions release and Ti2Ag precipitates contributed to the antibacterial ability, in which nano-scale and homogeneously distributed Ti2Ag phases would play a key role in antibacterial process.