Fabrication of piezoelectric fibers with metal core

A study on the fabrication of Pb(Nb,Ni)O₃-Pb(Zr,Ti)O₃ (PNN-PZT) piezoelectric ceramic fibers with a metal core is introduced. The green fibers were fabricated by extruding a mixture of PNN-PZT powder and organic solvent together with a 50 mm Pt core. The fibers of 250 mm in diameter and a few centimeters long are obtained without any cracks after sintered at 1200°C. The core is precisely located at the center of the fibers. The boundary of the PNN-PZT ceramics and the Pt core was investigated by cutting the fiber along the cross-section and the longitudinal direction, and observing them with a scanning electron microscope. The ferroelectricity and piezoelectricity of a single fiber was confirmed. The polarization versus electric field relationship was measured by a Radiant RT-6000 and the result exhibits the typical ferroelectricity of the PNN-PZT material. The strain versus electric field relationship also shows the typical hysteresis of piezoelectric materials due to the d₃₁ effect.