Aging of piezoelectric composite transducers

The effect of aging on some piezoelectric properties, including d(33), K-33 , and d(33)g(33) in 1-3 composite transducers has been evaluated in this ar ticle. The spontaneous changes of properties of piezocomposites (lead zirco nate titanate/epoxy) and piezoceramic under zero external stress was measur ed at 5 days and 500 days after poling. The results show that the aging beh avior in piezoelectric composites is very much dependent on the ceramic con tent. The composite material behaves similar to a piezoceramic at high volu me fraction of ceramic, i.e., greater than 25 vol. %. At low volume fractio n of ceramic, however, the rate of aging is much higher in piezoelectric co mposite compared to that of the piezoceramic. At lower than 25 vol. % of ce ramic, it was seen that the aging rate increases with decreasing the cerami c content. (C) 2001 American Institute of Physics.