Piezoelectric PZT tubes and fibers for passive vibrational damping

Passive vibrational damping was demonstrated in piezoelectric lead zirconate titanate (PZT) tubes incorporated into a hard epoxy matrix. For a poled tube, the coupling constant k₃₃, measured from the resonance frequency, was about 0.66. Sol-gel methods were used to fabricate piezoelectric fibers of Pb(Zr_0.52Ti_0.48)O₃ and niobium- and CdBO₃-substituted PZT. Continuous and fine gel fibers of about 5 to 100 μm in diameter were prepared by extruding and drawing spinnable viscous resins through a spinnaret. When fired at 600°C for 1 h, these fibers exhibited well-crystallized perovskite phases of PZT. Fibers fired between 700° and 1250°C were dense with varying grain sizes (0.1 to 5 μm). The dielectric constant of Pb(Zr _0.52Ti_0.48)O₃ fiber that was fired at 700°C for 1 h was about 800. These fibers will be incorporated into structural materials to obtain maximum damping properties