Co‐firing of PZN‐PZT Flextensional Actuators

Abstract

Flextensional actuators composed of a piezoelectric PZN‐PZT layer and a conducting PZN‐PZT/Ag layer were fabricated. Because the newly developed PZN‐PZT was sinterable at low temperature (<900°C), silver particles could be co‐fired with the PZN‐PZT. Therefore, an electrically conducting PZN‐PZT/Ag layer was fabricated by mixing the silver particles with PZN‐PZT powder. When 30–50 wt% Ag particles were mixed with the PZN‐PZT, the resulting composites showed a high‐electrical conductivity and low‐densification mismatch with respect to the PZN‐PZT layer. The PZN‐PZT/Ag layer had approximately the same resistivity as pure silver, because of the presence of a conducting channel of dispersed silver particles in the PZN‐PZT matrix. Two‐ and three‐layered actuators were fabricated with a diameter of 20 mm and a thickness of 0.9 mm using these PZN‐PZT and PZN‐PZT/Ag composites. When an electric field was applied, the fabricated actuators bent into a convex dome shape, yielding a large axial displacement at the center.