Sintering properties of zirconia-based ceramic composite

Abstract

This study examines the effects of different ZrB₂ content on various mechanical properties and electrical conductivity of ZrB₂/Y-TZP composite. Composites with ZrB₂ 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 ZrB₂ 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 ZrB₂ 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 ZrB₂ content of 20 wt-% and sintering temperature of 1400°C.

Keywords:

• Y-TZP
• Zirconia
• ZrB₂
• Composite
• Sintering
• Density
• Mechanical properties
• Resistivity

Acknowledgements

The authors acknowledge University of Malaya for providing the necessary facilities and resources for this research. This research was supported by the PPP Grant No. PV098-2012A and UMRG Grant No. CG022-2013.