Sol–gel synthesis of TiO2-modified nanocomposite coatings on titanium

Titanium dioxide nanoparticles-modified nanocomposite coatings were synthesized on titanium by sol–gel process. The specimens were studied by differential scanning calorimetry, transmission electron microscopy, field-emission scanning electron microscopy and bonding tests. TEM results showed that TiO2 nanoparticles were adhered and enwrapped in the hybrid sol matrixes to form aggregates of TiO2 nanoparticles. The size of the particle aggregates increased from about 160\ua0nm to above 500\ua0nm with the content of the TiO2 particles increasing from 45 to 60\ua0ma%. At the same time, the quantities of the microcracks on the coating surface gradually decreased. The solid phase content of the sols was increased by the addition of TiO2 nanoparticles, which avoided the formation of microcracks on the coatings surface. Compared to the uncoated group, the highest bonding strength improvement of about 24\ua0% was obtained at the TiO2 content of 60 ma%. Graphical Abstract: [Figure not available: see fulltext.