Abstract
An initial TiO2 coating was applied on Ti6Al4V by electrochemical anodisation in two dissimilar electrolytes. The secondary calcium phosphate (CaP) coating was subsequently applied by immersing the substrates in a simulated body fluid (SBF) with three times concentration (SBF×3), mimicking biomineralisation of biological bone. Electrochemical impedance spectroscopy and potentiodynamic polarisation assessments in SBF revealed that the anodic TiO2 layer is compact, exhibiting up to four-folds improvement in in vitro corrosion resistance over unanodised Ti6Al4V. X-ray photoelectron spectroscopy analysis indicates that the anodic Ti oxide is thicker than air-formed ones with a mixture of TiO2-x compound between the TiO2/Ti interfaces. The morphology of the dense CaP film formed, when observed using scanning electron microscopy, is made up of linked globules 0.1-0.5μm in diameter without observable delamination. Fourier transform infrared spectrometry with an attenuated total internal reflection analysis revealed that this film is an amorphous/poorly crystallised calcium-deficient-carbonated CaP system. The calculated Ca:P ratios of all samples (1.14-1.28) are lower than stoichiometric hydroxyapatite (1.67). These results show that a duplex coating consisting of (1) a compact TiO2 with enhanced in vitro corrosion resistance and (2) bone-like apatite coating can be applied on Ti6Al4V by anodisation and subsequent immersion in SBF.
| Original language | English |
|---|---|
| Pages (from-to) | 1087-1095 |
| Number of pages | 9 |
| Journal | Biomaterials |
| Volume | 26 |
| Issue number | 10 |
| DOIs | |
| Publication status | Published - Apr 2005 |
| Externally published | Yes |
ASJC Scopus Subject Areas
- Bioengineering
- Ceramics and Composites
- Biophysics
- Biomaterials
- Mechanics of Materials
Keywords
- Biocompatibility
- Biomimetic
- Calcium phosphate
- Corrosion
- SBF
- Titanium oxide