Effects of attrition milling on precursors of Al2O3 and 12Ce-TZP powders.

The influence of attrition milling on the chemical precursors of alumina and tetragonal zirconia polycrystal (12 mol% CeO2) is studied, with particular attention to the morphology, the specific surface area, the crystallographic form and the sinterability of powders obtained by (i) calcining the pristine precursors and (ii) milling the pristine precursors and then performing the calcination. It has been demonstrated that in the latter case the specific surface area is reduced but the sinterability is increased with respect to the former one. This behaviour is due to the destruction, by the attrition milling, of the porous microstructures and of the large aggregates in the “as-prepared” materials. The influence of milling is more evident in the alumina precursor, since it contains a high quantity of organic matter and therefore exhibits a very porous microstructure with a high specific surface area.