High pressure compaction and densification at 1200 ºC of nano-sized ZrO2-3 mol% Y2O3 powders obtained by sol-gel process

Abstract

In the present work, ZrO2-3 mol% Y2O3 (Y-TZP) nanoparticles prepared using the sol-gel method are incorporated in a matrix and uniaxially compacted by applying different pressures. Sol-gel powders are highly reactive, but the aim of obtaining full densification at low sintering temperatures is often not achieved. Thus, to obtain dense pieces with these powders requires a higher sintering temperature and this has a negative effect on their mechanical properties. However, if one obtains a higher density of green compact favours the subsequent densification process of the final piece. In this work, to obtain the compact ones three kinds of zirconia powders are prepared in different ways. Their compaction to high pressures and sintering behaviour are studied and correlated with the densification tests. The green compacts obtained show elevated densification, small grain sizeand improving mechanical properties after the thermal treatment at 1200 ºC in air.