SEM images in Fig. 13 illustrate the influence of the calcination
temperature on the morphologies of a-Al2O3 obtained from Al-8. It
can be seen that as the calcination temperature increased from
1000 to 1100 C, the morphology of a-Al2O3 transformed from
approximately spherical sharp to vermiform sharp, besides, the
obtained a-Al2O3 powder was seriously aggregated and connected
with each other. The particle size of a-Al2O3 increased from 50 nm
to 250 nm. Which was attributed to the particle growth through
the coalescence and densification process of the initial particles