INFLUENCE OF PRODUCTION CONDITIONS ON THE DENSIFICATION OF ZIRCONIA POWDERS OBTAINED FROM ACETATES

Tetragonal yttrium-stabilized zirconia samples were obtained by pyroly sis of amorphous acetates containing both metals, at 950-degrees-C in air. The dilatometric behaviour of samples indicates a dedensification when pyrolysis is carried out with a non-linear heating rate causing an absence of fine open porosity. A destabilization when cooling is ob served for samples exhibiting a wide granulometry with agglomerate siz es reaching 100 mum. Even when neither one, nor the other phenomenon i s noticed, an important aggregation state of the starting powders limi ts the densification and leads to poor sintered densities.