| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 811168 | Journal of the Mechanical Behavior of Biomedical Materials | 2011 | 10 Pages |
Alkali-heat treatment (AHT) is a simple and practical method to make titanium surfaces bioactive. Hydroxyapatite nucleates on Ti when in contact with body fluids due to the presence of a thin sodium titanate film produced by the AHT. This method was proposed more than a decade ago and it has been widely investigated at varied scopes. However, there is still little information about the mechanical properties of this film. In this work, the tribo-mechanical behavior of films produced by alkali treatment (AT) and AHT on Ti is investigated using instrumented indentation technique. The films were also characterized by TF-XRD, SEM, EDS and in vitro bioactivity tests. Analytical methods were employed to obtain the mechanical properties of the film from instrumented indentation data. The heat treatment subsequent to the alkaline processing increased the film elastic modulus from 1.7 GPa to 2.8 GPa, the hardness from 12 MPa to 20 MPa and the critical load for scratch test from 1.5 mN to 5.5 mN. Despite the overall improvement in the film bioactivity and tribo-mechanical behavior, the AHT elastic modulus is only 2% of the pristine Ti whereas hardness is less than 1%. This information must be considered for implant design purposes.
Research highlights► Heat treatment improved both bioactivity and tribo-mechanical behavior of the film. ► The films elastic moduli were 1.7 GPa (AT) and 2.8 GPa (AHT). ► Hardness was estimated as 12 MPa (AT) and 20 MPa (AHT). ► The scratch resistance increased 4 times from AT to AHT. ► Tribo-mechanical features of the AHT film are only around 1% the pristine Ti ones.
