Disperse Equiaxed α-Al2O3 Nanoparticles Without Vermicular Microstructure

Nanocrystalline microstructure is regarded as a strategic approach to overcome the brittleness of alumina ceramics, and the preparation of disperse equiaxed alpha-Al2O3 nanoparticles is an essential step for the preparation of nanocrystalline alumina ceramics. In this work, disperse equiaxed alpha-Al2O3 nanoparticles were prepared using alpha-Fe2O3 as seed and isolation phase. At first, the composite of alpha-Al2O3 nanoparticles embedded in alpha-Fe2O3 matrix was obtained by calcining the precursor powder containing gamma-AlOOH and Fe(OH)(3) (Fe3+/Al3+ mole ratio of 5) at 770 degrees C for 2 h. Then disperse equiaxed alpha-ZAl(2)O(3) nanoparticles with a mean size of 12 nm and a size distribution from 2 to 40 nm without vermicular microstructure were obtained by removal of alpha-Fe2O3 and other impurities in the composite through acid corrosion.