Construction of multi-layered Zn-modified TiO2 coating by ultrasound-auxiliary micro-arc oxidation: Microstructure and biological property.

Surfaces with desirable cytocompatibility and bactericidal ability are favoured for orthopaedic implants to stimulate osteogenic activity and to prevent implant-associated infection. In this work, we creatively introduce ultrasonic vibration (UV) to micro-arc oxidation (MAO) process and explore its influence on the microstructure, corrosion property and biological responses of Zn-modified TiO2 coating. With the introduction of UV, a uniform surface layer with homogeneously-distributed clusters could be produced as the outer layer, which possesses a fusion band with the underlying TiO2. The microstructural modification associated with UV results in the enhanced corrosion resistance, increased adhesive strength and improved biological performances of the resultant coating relative to that with the absence of UV. Hence, the ultrasonic auxiliary micro-arc oxidation (UMAO) is regarded as a promising surface modification method to produce Ti-based orthopaedic implants of high quality.