Mechanical and electromechanical properties of monoclinic ZrO2 fiber/PZT composites

Mechanical and electromechanical properties of mono-clinic 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 K1C of 1.4MPa &middot m 1/2 , 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 K1C&middot 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.