Effect of PbO content, loading rate and poling on mechanical properties of tape-cast and sintered PZT wafers

The effect of PbO content on the elastic modulus, hardness and fracture toughness of tape-cast and sintered PZT wafers was investigated using instrumented indentation based techniques. It was found that hardness and elastic modulus remained more or less unchanged whereas the fracture toughness increased with increasing PbO content. The effect of loading rate of indentation on the hardness and elastic modulus of the PZT wafer having near-morphotropic composition was also studied. It was found that the hardness increased initially with increasing loading rate up to a loading rate of 50 mN/min and subsequently decreased with further increase in loading rate. On the other hand, elastic modulus remained more or less unaffected. The effect of poling on the mechanical properties of the near-morphotropic PZT wafer was also investigated. Poling was found to result in a decrease in fracture toughness, although it did not have a significant effect on the hardness and elastic modulus.