The phase transformation of gibbsite to corundum (α-Al203) in 1,5-pentanediol (glycothermal treatment) was investigated between 270 and 450°C and between 10 and 50 MPa. The kinetics of transformation to corundum in this range are hindered. Only the formation of microcrystalline tohdite (5 A1203 : 1H20 ) can be observed. The lowering of the nucleation energy of corundum by adding α-Al203 seeds enables the synthesis of microcrystalline corundum at 330°C. The size of the gibbsite particles and the size and quantity of the α-Al203 seeds are important for the homogeneity and particle size of the resulting corundum. The particle size and the
morphology of glycothermal α-Al203 powders were compared with the results of hydrothermal synthesis of α-Al203.
|Journal||Journal of the European Ceramic Society|
|Publication status||Published - 1994|