; Zhou, Ying
; Li, W.
; Sun, Chunhui
; Jun, Shangxue
; Ye, G.
Preparation of Sphere-Like α-Al2O3 from Commercial Al(OH)3 with a Mechanical Ball Milling Process
Refractories Manual (2016) 60-64
In comparison to the typically worm-like α-Al2O3 powders of 20–30 µm size from unmilled Al(OH)≤ precursor fired at 1450 °C, almost-spherical α-Al2O3 powders of ˜0.5 µm size were synthesized from 9 h-milled Al(OH)3 precursor with the same heat treatment. The effect of the commercial Al(OH)3 precursor milling treatment on phase transformation and morphology of α-Al2O3 was studied by XRD and SEM. It was found that the milling treatment of the commercial Al(OH)3 precursor not only led to an acceleration of α-transformation during calcination, but also changed the morphology and particle size distribution of the α-Al2O3 powders. As the Al(OH)3 precursors were broken into irregularly shaped pieces with a ≤1 µm size range by the milling treatment, the resulting sharp corners with high vapor pressure would alter the evaporation-condensation mechanism into one that is mainly based on diffusion in the α-Al2O3 calcination process and promotes the tendency to form spherical α-Al2O3 powders.
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