Mechanical and Electromechanical Properties of Monoclinic ZrO2 Fiber/PZT Composites

Mechanical and electromechanical properties of monoclinic ZrO2 fiber/PZT composites fabricated by slip casting and ordinary sintering were examined. Bending strength of the composites decreased by increasing the fiber content from 0 to 20vol%. However, the composite containing 5vol% ZrO2 fibers yielded a fracture toughness KIC of 1.4MPa⋅m1/2, 75% higher than that of PZT matrix. The measurement of thermal expansion and observation of microstructure suggest that microcracking, crack bowing and crack deflection contribute to the increase in KIC. Addition of ZrO2 fibers reduced both permittivity and coupling factor K31 of the composites. At 5vol% ZrO2, the K31 value of the composite was 25% lower than that of PZT matrix.