Composites of PZT and Epoxy for Hydrostatic Transducer Applications

Composites with 3–1 connectivity for transducer applications were made by embedding extruded PZT rods in an epoxy matrix. The effects of rod diameter, volume fraction of PZT, and composite thickness on the hydrostatic properties of the composites were determined. Due to decoupling of the d̄ 33 and d̄ 31 coefficients in a composite with 3–1 connectivity, the d̄ n may be enhanced, even in composites of low volume fractions of PZT. Such composites alsojiave a low dielectric permittivity. The combination of high d̄ n values and low ɛ 33 value results in a greatly enhanced ḡ n . Composites with 10 vol% PZT were made with values of d̄ h and ḡ h which are, respectively, two times (>80×10 −12 C/N) and 25 times (>70×10 −3 (V·m/N) the solid PZT values.