Effect of Magnesium Addition on the Phase Transformation of α-Alumina Prepared from Route of Ammonium Aluminum Carbonate Hydroxide
Effect of magnesium addition on rapid transformation of α-alumina prepared from route of ammonium aluminum carbonate hydroxide during thermal heating and microwave radiation heating was investigated. The phase transformation and the final particle size of the transient alumina composite powder were significantly affected by amount of magnesium added in the aluminum precursor during the microwave radiation heating in various environmental atmospheres. Rapid transformation from γ- to α-phase was found in the magnesium added transient alumina by microwave-assisted transformation and nano-sized α-alumina was obtained. When the 3 wt% magnesium added ammonium aluminum carbonate hydroxide was heated by microwave radiation under nitrogen atmosphere, the transformation temperature from γ- to α-alumina was considerably lowered to 1000°C and the average particle size of 27.6 nm was attained for the α-alumina-spinel composite powder.
Chang Kyu Rhee
Y. M. Jung and S. W. Kim, "Effect of Magnesium Addition on the Phase Transformation of α-Alumina Prepared from Route of Ammonium Aluminum Carbonate Hydroxide", Solid State Phenomena, Vol. 135, pp. 139-142, 2008