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

Abstract

Abstract In the present work, ZrO2-3 mol% Y2O3 (Y-TZP) nanoparticles prepared by sol-gel method are incorporated in a matrix and uniaxially compacted applying different pressures. Sol-gel powders are of high reactivity, but very often the aim to obtain full densification at low sintering temperature, is not achieved. Thus to obtain a dense pieces with these powders require a higher sintering temperature and this has a negative effect on their mechanical properties. However, if one obtains 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 obtained green compacts show elevated densification, small grain size and improving mechanical properties after the thermal treatment at 1200 ºC in air.