反铁电相变陶瓷低频发射换能器

Antiferroelectric phase transitions ceramics low frequency projector

在具有高阶形式的广义压电方程基础上,讨论掺镧改性锆锡钛酸铅PbLa(Zr,Sn,Ti)O_3(PLZST)反铁电相变陶瓷的非线性机电耦合问题,得到类似传统线性压电方程的近似线性电致伸缩方程,给出了一种解决非线性反铁电相变陶瓷换能器电声转换问题的分析方法,即在直流偏置状态下对PLZST反铁电相变陶瓷的材料参数进行近似线性等效化处理进而分析换能器的电声转换问题。在此基础上,研制了水中谐振频率1.1 kHz新型反铁电相变陶瓷低频弯张换能器。湖上试验结果表明,与同结构同尺寸压电陶瓷弯张换能器相比,目前反铁电换能器样品的发射电压响应约高3 dB,声源级高出9 dB,并验证了本文所提出的分析非线性反铁电相变陶瓷换能器方法的正确性。

In order to discuss the nonlinear electromechanical properties of the La-modified lead zirconate titanate stannate antiferroelectric ceramics PbLa（Zr, Sn,Ti）O3 （PLZST）, the approximate linearized electrostrietive equations exactly the same form as the classical linear piezoelectric equations were derived from the second-order terms of the generalized piezoelectric equations. An analytic approach of solving the electroaeoustic transduction problems of the nonlinear antiferroelectric phase transitions ceramics transducers was presented. The nonlinear properties of the PLZST can be linearly equivalent with a maintained bias based on the approximate linearized electrostrictive equations for analyzing the electroacoustic transduction problems of the transducers. An innovative anti- ferroelectric ceramics low frequency class IV flextensional transducer with resonance frequency 1.1 kHz based on the approach was developed which utilizes the PLZST as active elements. The lake authentications indicated that the use of PLZST for transducers yielded presently a 3 dB increase in TVR and a 9 dB increase in SL over its PZT-4 counterpart, and the approach was valid.