Fabrication of oxide coatings containing bismuth silicate or bismuth titanate on titanium

Oxide coatings formed on titanium in electrolytes with Na2B4O7 or Na2SiO3 by the method of plasma electrolytic oxidation and containing TiO2 or SiO2, respectively, were impregnated in an organic solution of bismuth and, thereafter, annealed in air at 700 °C. As a result, layered oxide coatings containing, aside from titanium and silicon oxides, crystalline phases of bismuth titanate (Bi4Ti3O12) or silicate (Bi2SiO5) were obtained. The composition and structure of the coatings surface parts and the distribution of bismuth-containing compounds over the surface have been investigated.