Effect of hydroxyapatite and Ag, Ta2O5 or CeO2 addition on the properties of ultrafine-grained Ti31Mo alloy

In the present study, the crystal structure, microstructure, mechanical and corrosion properties of bulk Ti31MoxHA composites (x = 0, 2.5, 5 and 10 wt %) were investigated. The sintering of Ti31MoxHA powders led to the formation of a bulk composite with grain size of approx. 1 mu m. All these composites have elastic modulus lower than CP microcrystalline alpha-Ti, and their hardness is two times higher. The ultrafine Ti31Mo5HA composite was more corrosion resistant in Ringer solution than the bulk Ti31Mo alloy. Surface wettability measurements revealed the higher surface hydrophilicity of the bulk ultrafine-grained Ti31Mo10HA sample in comparison to microcrystalline Ti sample. Ti31Mo5HA composites with the addition of 1 wt % Ag, 2 wt % Ta2O5 or 2 wt % CeO2 were synthesized, too. The antibacterial activity of Ti31Mo5HA composite containing silver (Ag), tantalum (V) oxide (Ta2O5) or cerium (IV) oxide (CeO2) against Staphylococcus aureus was studied. In vitro bacterial adhesion, study indicated a significantly reduced number of S. aureus on the bulk ultrafine-grained Ti31Mo5HA-Ag (Ce2O3) plate surfaces in comparison to microcrystalline Ti plate surface. Ultrafine-grained Ti31Mo5HA - Ag or CeO2 biomaterials can be considered to be the future generation of medical implants. (C) 2020 The Authors. Published by Elsevier B.V.