压电复合材料的现状与展望

The Present Situationand Prospect of Piezoelectric Composites

由压电陶瓷相和聚合物相组成的压电复合材料是本世纪 70年代发展起来的一种多用途功能复合材料。由于柔性聚合物相的加入 ,压电复合材料的密度 ( ρ)、声阻抗 (Z)、介电常数 (ε)都降低了 ;而复合材料的优值 (dhgh)和机电耦合系数 (kt)却提高了 ,这使压电复合材料能在水听器、生物医学成像、无损检测、传感器等诸多方面被广泛地用作换能器。本文对压电复合材料的发展、现状、展望及其性能影响因素作了概述。由于1— 3型复合材料有较好的性能 ,所以着重叙述了它的特点。本文最后讨论了压电复合材料的设计原则。

Amultipurposefunctionalcompositematerials ,piezoelectriccompositesconsistingofapiezoelectricceramicphaseandapolymerphasehasbeendevelopedsincethe 1970s .Byreplacingaportionofthepiezoelectricceramicwithaflexiblepolymer ,thedensity ( ρ) ,a cousticimpedance (Z)anddielectricpermittivity (ε)ofpiezoelectriccompositescanbelowered .Moreover ,thefigureofmerit (dhgh)and thickness -modeelectromechanicalcouplingcoefficient (kt)increase .Asaresult,piezoelectriccompositesareextensivelyusedastransduc ersinhydrophone ,ultrasonicbiomedicalimaging ,nondestructivetestandsensorsetc .Inthepaper ,development ,factorsinfluencingprop erties ,recentstatusandprospectarereviewed .Compositeswith 1— 3connectivitypatternhavebetterproperties ,socharactersof 1— 3 compositesareintroduced .Finally ,principlesfordesignofpiezoelectriccompositesarediscussed .