不同升温方式对碳酸铝铵热分解制备纳米α-Al_2O_3粉体的影响

The effect of different heating modes for ammonium aluminium carbonate hydroxide on the synthesis of α-Al_2O_3 nanopowders

以合成的碳酸铝铵为原料;;采用不同升温方式;;研究了Al2O3相转变历程.研究表明;;提高800?C前的升温速度可使各Al2O3相形成温度明显降低.将碳酸铝铵从800?C升温到1050?C保温1.5h或从室温升温到1150?C可获得颗粒尺寸分别为40;;80nm单相α-Al2O3纳米粉体.

The procedures of phase transformation of Al2O3, via thermal decomposition of ammonium alu- minium carbonate hydroxide NH4AlO(OH)HCO3 or AACH synthesized with ammonium aluminium sulfate NH4Al(SO4)2 and ammonium hydrocarbonate NH4HCO3 were studied. It is demonstrated that, as the heating rate of the AACH increased below the temperature of 800?C, the phase formation temperatures of di?erent Al2O3 phases decrease. Single phase α-Al2O3 powders were obtained by heating the AACH for 1.5 h at 1050?C from 800?C or heating the AACH for 2.0 h at 1100?C at room temperature. The average particle sizes of the α-Al2O3 powders obtained from these two heating modes are 40 and 80 nm, respectively.