Zirconia Nanoceramic via Redispersion of Highly Agglomerated Nanopowder and Spark Plasma Sintering

GUSTAVO SUÁREZ; HANNA BORODIANSKA; YOSHIO SAKKA; ESTEBAN F. AGLIETTI; OLEG VALYLKIV

JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY

AMER SCIENTIFIC PUBLISHERS

Año: 2010 vol. 10 p. 6634 - 6640

1533-4880

A 2.7 mol% yttria stabilizing tetragonal zirconia (2.7Y-TZP) nanopowder was synthesized and stored for five years. Humidity and unsatisfactory storage conditions gradually caused heavy agglomeration. Within a few months, 2.7Y-TZP nanopowder became useless for any technological application. A bead-milling deagglomeration technique was applied to recover the heavily agglomerated yttria-stabilized zirconia nanopowder. Low-temperature sintering and spark plasma sintering (SPS) were performed, resulting in fully dense nanostructured ceramics. Compacts formed with heavily agglomerated powder present low sinterability and poor mechanical properties. Bead-milling suspension formed compacts exhibit mechanical properties in the range of the values reported for nanostructured zirconia. This observation confirms the effectiveness of bead-milling in the deagglomeration of highly agglomerated nanopowders.  The high value of Vickers hardness of 13.6 GPa demonstrates the success of the processing technique for recovering long-time-stored oxide nanopowders.