Effect of ZnO whisker content on sinterability and fracture behaviour of PZT peizoelectric composites

Zinc oxide whiskers (ZnOw) reinforced lead zirconate titanate (PZT) piezoelectric composites with high strength and high toughness were fabricated by nonpressure sintering at 1100 °C. Addition of ZnOw is effective for sinterability and densification of the composites. Incorporating ZnOw to PZT ceramics contributes to an obvious improvement of the fracture properties. The fracture strength and fracture toughness of the composites incorporating 2 wt.% ZnOw, compared with the monolithic PZT, are enhanced 46% and 47%, respectively. Improvement of fracture strength is ascribed to the enhancement of the elastic modulus and fracture toughness. Enhancement of fracture toughness is associated with the existence of the observed several mechanisms including crack deflection, whisker bridging, whisker pull-out and rupture due to the intergranular and intragranular whiskers.