Relationship between the mechanical properties and microstructures of sintered PZT

PZT materials are increasingly being used in infrared sensors, transducers and actuators. The use of these sensor elements require materials with a high degree of reliability and mechanical integrity. In view of the extreme brittleness of PZT materials, there is a need to understand the factors responsible for the poor mechanical properties. Samples in the form of circular discs and rectangular bars were sliced from isostatically pressed and sintered rods. These were polished prior to the 3-point bend test and the circular ring test. The fracture strengths were found to range from 80 to 120 MPa, and Weibull moduli of about 7 to 18 were obtained. The fracture toughness of the sintered PZT materials has been studied using indentation technique. The results are presented and discussed in relation to the microstructures evolved.