Effects of multicomponent catalyzer on preparation of ultrafine α-Al2O3 at low sintering temperature

α-Al2O3 powder, with a purity of 99.95% and an average particle size of 80 nm, was prepared via the thermal decomposition of AACH precursor. During the AACH preparation, OP-10 (alkylphenol ethoxylates) was used as a dispersant and a deflocculating agent, and a self-confected multicomponent catalyzer (MC) was used to prevent powder agglomeration. Our experiments illustrated that: apart from the necking and agglomeration-preventing effect during the sintering process, MC had potential promotive effects on the reduction of α-Al2O3 phase transformation temperature by maintaining the powder particles in a comparatively dynamic-sintering state, thus significantly improving the dispersibility of the sintered powder. BET and ICP analyses indicated that MC was propitious for increasing the specific surface area of the formed α-Al2O3 powder and induced very tiny impurities in the sintered products.