Abstract: Tantalum (Ta) alloys have been widely used as bone repair materials due to their excellent biocompatibility. In present work, zinc (Zn) incorporated ceramic coatings with micro/nano hierarchical structure were successfully fabricated on Ta by micro-arc oxidation and hydrothermal treatment. The content of Zn ions is about (1.35 ± 0.3) wt%. Cortex-like rough morphology (Ra: 1.504 μm) with irregular vermiform slots can be clearly observed on the surface of Ta. More importantly, the coatings resembling the structure of natural bone can release Zn, Ca, and P ions in a controlled and sustained manner. The corrosion resistance of Ta is greatly improved after functionalized with ceramic coatings, confirming by potentiodynamic polarization tests. The bonding strength between the coatings and substrates can be up to 18.9 N. Furthermore, the surface of MAOs-HT@Ta is covered by bonelike apatite after immersed in Simulated Body Fluid (SBF) for three weeks, showing excellently bioactivity. These results suggest that the innovative Zn-incorporated micro/nano hierarchical coatings on Ta may be used as promising candidates for orthopedic implants.

Key words: micro-arc oxidation, micro/nano hierarchical structure, bioactivity coatings, corrosion resistance