MONOCLINIC ZIRCONIA SINTERED BODIES PREPARED VIA TWO-STEP SINTERING AND CHARACTERISATION OF SELECTED MECHANICAL PROPERTIES

摘要

In the paper we examine some mechanical properties of the unstabilised zirconia sinters, such as Vickers hardness andfracture toughness. The sinters were prepared using two step sintering technique. It is the first time, when two step sinteringis used to process unstabilised zirconia nanopowders. As a preparatory experiment, a microstructure evolution of the sinterswas determined in order to select the temperatures T_(1) and T_(2) of two step sintering. The samples were sintered below themonoclinic to tetragonal transformation temperature, using several T_(1) and T_(2) combinations and different sintering times. Thesinters were compared in terms of density, grain size, Vickers' hardness and fracture toughness. The samples were sintered tofull density, showing a grain size of 95 nm, Vickers hardness of 11 GPa and fracture toughness of 5.32 MPa?m~(0.5).