Ti-based nanocoatings on Al2O3 powders

Ti-based nanocoatings on ceramic powders were successfully fabricated by heterogeneous precipitation method. Commercial Al2O3 (average particle size of 0.5 μm), titanium tetrabutoxide (Ti(C4H9O)4) and urea (CO(NH2)2) have been used as starting materials. Selecting appropriate precipitation conditions, both the thickness and the uniformity of Ti-based nanocoatings were adjusted. With a molar ratio TiO2/Al2O3 = 0.05 and the use of urea in excess, a homogeneous nanocoating of ∼20 nm on the alumina powder surface was attained. FTIR spectra indicated the formation of the TiO2-based nanocoating onto Al2O3 particles and TEM examinations showed that the amorphous coating layer crystallized to <10 nm TiO2 particles upon calcination at 500 °C.