Synthesis of alumina powders with addition of seeds through Pechini Method

Synthesis of alpha-alumina powders is normally accompanied by an inherent crystal growing during the calcination process, since this phase usually forms in temperatures above 1200°C. Many researches have been attempting to reduce the formation temperature of alpha-alumina, in order to obtain a stable powder with finer granulometry. In this work it was studied the chemical synthesis of ultrafine powders of alumina, adding 10% in weight of alpha-alumina seeds, using the Pechini method. The obtained polymeric precursors were pre-calcinated at 500°C in order to eliminate organics, and the resulting product was calcinated at 900°C, 1000°C and 1100°C to verify the present phases. The powders had their morphology and microstructure characterized by X-ray diffraction, scanning electron microscopy and infrared spectroscopy. It was observed an influence of seeding with alpha-alumina on the formation temperature of this phase during the calcination process. (author)