铁电和压电效应的电致疲劳综合建模研究

A synthetic model of electric fatigue for ferroelectric materials with ferroelectric and piezoelectric effects

铁电材料具有良好的铁电、压电、热释电等特性,被广泛应用于超声和声纳传感器等众多领域。根据其铁电电畴结构及其极化反转特性,实验中常可测得两种特征回线,即铁电极化回线和压电蝴蝶回线。理论而言,单纯外电场强度影响下的特征回线应呈现规则对称形状,然而,由于一些不可避免的原因(如,电畴极化不稳定、缺陷密度及电致疲劳等),均使得以上回线逐步退化,进而呈现非对称非线性回线,无疑为此类智能材料的力-电建模问题增加了难度,限制了该材料在工程中的应用。由于铁电材料所制成的器件通常是在循环交变电场下服役,或在力、电、温度等多场下工作,于是场致疲劳已成为铁电器件应用的主要障碍。基于此,提出一类电致疲劳综合模型,充分考虑由于循环电场极化导致的材料疲劳现象,对铁电和压电特征曲线进行较为全面和精确地描述。最后,利用实验数据对所提模型进行了验证,结果表明其精确性和适应性均优于传统模型方法,具有很好的应用前景。

Ferroelectric materials are applied in many fields,such as,ultrasonic and sonar transducers etc.due to their distinct ferroelectric and piezoelectric properties.Their characteristic loops measured in experiments are generally nonlinear and hysteretic.These loops gradually become degenerate and asymmetric due to some inevitable reasons,especially,electric fatigue to increase difficulties to their force-electricity modeling,and limit their application in engineering.Here,a synthetic model of electric fatigue was proposed fully considering material fatigue phenomena due to cyclic electric field polarization and precisely describing ferroelectric and piezoelectric characteristic loops.Finally,experimental data was utilized to verify the proposed model.The results showed that the accuracy and adaptability of the proposed model are superior to those of the traditional ones,and it has good prospects for application.