J. Akhtar et al., PHYSICOCHEMICAL STUDIES OF ZIRCONIA AND MAGNESIA DOPED ZIRCONIA CERAMIC POWDER, Journal of the Chemical Society of Pakistan, 19(2), 1997, pp. 93-103
Spherical fine zirconia (ZrO2) and 9 mol % magnesia doped zirconia (Mg
O-ZrO2) ceramic powders (diameter of similar to 0.2 mm) have been synt
hesized from a hydrothermally treated sol of zirconium and magnesium s
alts by spray pyrolysis. The results revealed that synthesized powders
can be sintered into uniformly sized fine grained ceramic of > 97% th
eoretical density at temperature as low as 1100 degrees C. The phases,
purity, crystallite size, agglomeration structure, particle size, spe
cific surface area, pore size distribution and porosity of ZrO2 and Mg
O-ZrO2 ceramics were measured by XRD, SEM, N-2-gas adsorption and Hg-d
iffusion techniques. The results of X-ray diffraction and scanning ele
ctron microscopy showed that the ZrO2 and MgO-ZrO2 remained amorphous
up to 700 degrees C, but on increasing the heat treatment temperature
to around 1200 degrees C for 8 hrs. monoclinic crystals were obtained.
Thermogravimetric (TG) and differential scanning calorimetric (DSC) t
echniques were used to measure the burnout temperatures and enthalpy (
Delta H) of polyvinyl alcohol (PVA) and methylcellulose (MC) polymers
used as binders. Burnout of these polymers is 100% in an oxidizing atm
osphere; 90% burnout was achieved in an inert atmosphere.