Ultrasonic Induced Refinement of Induction Heated Oxide Coating on Titanium

Abstract

Induction heating treatment (IHT) has recently been used to improve the bioactivity and biocompatibility of titanium and its alloys, greatly related to the formation of the nanoscale oxide coating. In this work, the effect of ultrasonic on the IHT oxidation behavior of pure titanium has been investigated. Ultrasonic-assisted IHT of pure titanium was carried out for 13, 20 and 25 s. Submicro-/nano-scale morphological coatings with rutile and anatase TiO2 were prepared on the surface of titanium substrates subjected to ultrasonic-assisted IHT. In particular, the TiO2 crystals were significantly refined by ultrasonic impact. An improvement in hydrophilicity and hardness of the oxide film was achieved by ultrasonic-assisted IHT. The refinement of TiO2 crystals is suggested to be caused by ultrasonic induced changes of energy, defect density and their correlation with diffusion of oxygen. The present study provides a potential method to refine the nanoscale oxide films on titanium substrates, which is promising for improving the wear resistance and bioactivity of titanium and its alloys.