Sintering properties of zirconia-based ceramic composite

Abstract

This study examines the effects of different ZrB 2 content on various mechanical properties and electrical conductivity of ZrB 2 /Y-TZP composite. Composites with ZrB 2 content of up to 20 wt-% were particularly beneficial at the lower sintering temperature range by achieving greater densification and better hardness than Y-TZP monolith. In contrast to the trends estimated from rule of mixture, the increment of ZrB 2 content did not result in any significant improvement in the elastic modulus and hardness of the zirconia composites. Nevertheless, all composites showed tremendous improvement in fracture toughness compared with monolithic Y-TZP and thus, suggested that other toughening mechanisms were operative besides transformation toughening of zirconia. Incorporation of ZrB 2 up to mass fraction of 20 wt-% into Y-TZP generally did not affect the tetragonal phase stability of zirconia. Significant reduction of electrical resistivity of the composites was achieved with ZrB 2 content of 20 wt-% and sintering temperature of 1400°C.