Effect of SnO–SiO 2 composite coating on bonding of titanium–porcelain

The SnO–SiO₂ composite coating was deposited on titanium (Ti) by sol–gel dipping process. The adhesion between the Ti and porcelain was evaluated by three point flexure bonding test. The results of thermogravimetry and differential scanning calorimetry analysis showed that the optimal heat treating temperature for SnO–SiO₂ composite coating was 300°C. The SEM results revealed that the existence of microcracks on the SnO–SiO₂ composite coatings surface after being treated at 300°C. The Ti oxide was formed along the crack. Failure of the Ti–porcelain predominantly occurred at the SnO–SiO₂ composite coatings. SnO–SiO₂ composite coatings served as an effective oxygen diffusion barrier, improved the chemical bonding between porcelain and Ti and resulted in the increased bonding strength of Ti–porcelain.