Fabrication of Functionally Graded PZT/Pt Piezoelectric Actuators.

Piezoelectric materials have received increasing attention in the field of electromechanical system because they can readily transfer an electrical signal to a mechanical movement. Unimorph and bimorph actuators that contain a piezoelectric plate and a metal plate are widely used to generate a larger bending displacement than an extensionalmode transducer. However, degradation may occur at the organic bonding interfaces after long time service. In this work, to develop a functionally graded PZT/Pt piezoelectric actuator, PZT/Pt composites with various composition ratios were prepared and characterized. (1) Dense PZT/Pt composite samples without any chemical reaction between the PZT and Pt phases were obtained by sintering in air at 1200°C for 1 h. (2) The PZT/Pt composites that contained 20vol% Pt or less exhibited dielectric and piezoelectric properties, with piezoelectric constant decreasing with increasing Pt content. (3) FGM PZT/Pt bimorph actuators were designed using Taya's model and successfully fabricated via powder metallurgical routes.