The Effect of TiO2 Nanoparticles on the Surface Morphology and Drying of HA-TiO2 Composite Coating on NiTi Alloys by Electrophoretic Deposition

Nowadays, HA attracts a lot of attention as a bio-ceramic coating on metallic implants due to the its desired biological properties. In order to improve the properties of HA coating, especially cracking induced by drying and sintering, using of HA composite coatings are in the spotlight. In this study composite coatings of HA-TiO2 containing of 0, 5, 10 and 20 wt% TiO2 were coated using the electrophoretic deposition process on the NiTi substrates. The used suspension solution was mix of n-butanol and triethanolamine. The electrophoretic deposition was carried out at 60 V for 120 seconds on the cathode. After deposition, specimens were dried at room temperature and then sintered. The XRD and SEM were used to study the phases and microstructure of coatings, respectively. The composition of coatings were investigated using EDX. The results show that increase of TiO2 nanoparticles up to 10 wt% improves the drying behavior of coatings and the bonding strength of HA10% TiO2 coating increases up to 21.1 ± 2.3 MPa in compared to that of HA coating (18.1 ± 3.1 MPa).