Preparation and sintering behaviour of nanostructured alumina/titania composite powders modified with nano-dopants

Nanostructured alumina/titania composite powders were prepared by doping with small amounts of nanosized zirconia and ceria. The nanosized raw materials powders were reconstituted into nanostructured particles by ball milling, spray drying and heat treating. Then, the nanostructured reconstituted powders were cool-isostatic pressed and pressureless-sintered into bulk ceramics. The phase composition and microstructures of reconstituted powders and as-prepared ceramic composites were characterized by using X-ray diffractometer (XRD), scanning electron microscope (SEM) and energy-dispersive spectrometer (EDS). The sintering behaviour of the nanostructured ceramic composite powders and the effects of nano-dopants and sintering temperatures on the microstructures of the ceramic composites were investigated and discussed. It was found that nano-dopants could lower the sintering temperature and accelerate densification of ceramic composites.