Large Strain Lead-free Ceramic Materials for Actuators
In this paper we present a set of (Bi0.5- Na0.5)TiO3-based lead-free ceramics which can provide large strain in response to an external electric field. An effective piezoelectric constant, Smax/Emax, as high as 830 pm/V, is obtained in optimized compositions under proper exciting conditions. This value is comparable to some soft PZT ceramics used in modern multilayer actuators. Electromechanical measurements suggest that the large strain mainly arises from 1), the high electrostrictive contribution of a non-polar phase and 2), a field induced phase transition accompanied by a volume change. The temperature and frequency dependences of the electromechanical response are presented and discussed from the point of view of phase transition dynamics. The implementation of these non-piezoelectric effects and related ceramics for actuator applications is discussed based on the material properties and practical requirements.
Y.L. Wang A. B. Kounga C. Hoffmann
Corporate Materials Research & Development (CMRD),EPCOS OHG Siemensstrasse 43,8530 Deutschlandsberg,Austria
国际会议
西安
英文
130-133
2009-08-23（万方平台首次上网日期，不代表论文的发表时间）