Chemically reduced plzt ceramics for ultra-high displacement actuators

Abstract

A new and unique processing method for fabricating stress-biased, monolithic ceramic elements for ultra-high displacement actuators is reported. The technique consists of chemically reducing one surface of a high lead containing piezoelectric or electrostrictive wafer such as PLZT with solid graphite in an oxidizing atmosphere at an elevated temperature. This process produces a dome-like wafer structure which is the key to its high displacement characteristics and its enhanced load bearing capabilities. This new type of ceramic bender is capable of (1) achieving displacements as high as 3 mm from a single element, (2) sustaining point loads of about 10 kg and (3) distributed pressures of approximately 0.6 MPa. Designated as Rainbow ceramics, they have been successfully produced from both sintered and hot pressed material.