Formation of nanoporous titania on bulk titanium by hybrid surface mechanical attrition treatment

Titanium has been used as an important implant material in humans, and it is important to investigate the interaction between titanium and H2O2 produced from the inflammatory response during the implantation procedure. However, the reports about the interaction between H2O2 and nanostructured or ultrafine-grained Ti are still very limited. In this work, the interaction between H2O2 and bulk Ti with a nanostructure surface was reported. At first, a commercial pure Ti plate underwent a surface mechanical attrition treatment (SMAT) in vacuum for 1 h to produce a nanocrystalline layer of Ti about 30 μm thick. Then the SMAT Ti was immersed into hydrogen peroxide solution for 24 h at 25 °C, and nanoporous titania was produced on the SMAT Ti surface. The nanoporous structure could be retained even after calcinations at 600 °C, while only intergranular corrosion appeared in coarse-grained Ti after the same chemical treatment.