Preparation and Properties of 3Y-TZP — Al2O3 Nano-Composites

• Published in: Key Engineering Materials 2003-01, Vol.253, p.243-254
• Main Authors: Vasylkiv, Oleg, Sakka, Yoshio, Skorokhod, Valeriy
• Format: Article
• Language: English
• ISSN: 1013-9826; 1662-9795; 1662-9795
• DOI: 10.4028/www.scientific.net/KEM.253.243

Yttria-stabilized zirconia nano-powder, which only contains extremely small uniform aggregates, was prepared using hydrothermal preparation followed with ultrasonic deagglomeration technique. The control of agglomeration in the nano-size powder is of utmost importance in order to obtain highly sinter-reactive ceramic. The nano-aggregates appear to be the smallest microstructural units, which determine the resulting green microstructure and sintering behavior. The densification of the zirconia ceramic at low temperatures was possible only because of a very homogeneous microstructure, i.e. a highly uniform packing of nano-aggregates was achieved in the green compacts. To improve sinterability and ceramic properties the zirconia-alumina (1-5 wt.% of *g-alumina) nano-composites were prepared. We showed that full-dense nano-grained ceramic, with average grain size of #~ 95 nm, have been sintered at 1150DGC using hydrolytic-derived 3mol% yttria-stabilized zirconia and zirconia-alumina composite nano-powders. Nanostructured 3mol% yttria-stabilized zirconia ceramic was shown to reach hardness of 12.5 GPa. Addition of alumina intensified the sintering process and hardness increased to 15.6 GPa.