铁电复合材料介电击穿的相场模拟  

Phase Field Simulation of Dielectric Breakdown in Ferroelectric Composites

作　　者：王子荷 米璋 王杰[1] WANG Zihe;MI Zhang;WANG Jie(School of Aeronautics and Astronautics,Zhejiang University,Hangzhou 310027,P.R.China)

机构地区：[1]浙江大学航空航天学院,杭州310027

出　　处：《应用数学和力学》2024年第11期1428-1439,共12页Applied Mathematics and Mechanics

基　　金：国家重点研发计划课题(2022YFB3807601);国家自然科学基金(12272338,12192214)。

摘　　要：以铁电聚合物为基体和铁电陶瓷为填充物的铁电复合材料,克服了单相铁电材料大极化强度与高击穿强度二者不可兼得的关系,表现出优异的压电、储能等多场耦合性能,受到人们越来越多的关注.然而铁电复合材料界面的应力和电场集中会引发材料的力电耦合失效,其中介电击穿是铁电复合材料的主要失效方式之一.因此,理解陶瓷填充物对铁电复合材料介电击穿性能的影响,对其在高性能能量转换与存储器件中的应用至关重要.该文针对铁电复合材料的多场耦合失效问题,构建包含极化、应变和击穿序参量的相场模型,研究了铁电复合材料在电载荷作用下的介电击穿行为.相场模拟结果表明,随着陶瓷填充物颗粒尺寸的增大,电击穿路径会避开陶瓷颗粒,同时材料内部的最大电场会逐渐增大,从而导致复合材料的击穿强度会越来越低.此外,模拟结果还发现介电击穿强度与填充物颗粒尺寸之间呈现出非线性关系.该文研究结果为铁电复合材料介电击穿强度的设计提供了一定的理论基础.The ferroelectric composite material with ferroelectric polymer as the matrix and ferroelectric ceramic as the filler overcomes the inverted relationship between high polarization strength and high breakdown strength of single-phase ferroelectric materials,exhibits excellent multi-field coupling properties such as piezoelectricity and energy storage.Recently,it draws increasing attention.However,the stress and electric field concentration at the interface of ferroelectric composite materials can cause the electromechanical coupling failure of the materials,and the dielectric breakdown is one of the main failure modes of ferroelectric composite materials.Therefore,understanding the effects of ceramic fillers on the dielectric breakdown performances of ferroelectric composite materials is crucial for their application in high-performance energy conversion and storage devices.Aimed at the multi-field coupling failure of ferroelectric composite materials,a phase field model involving polarization,strain,and breakdown order parameters was established to study the dielectric breakdown behavior of ferroelectric composite materials under electrical loads.The phase field simulation results indicate that,as the particle size of the ceramic filler increases,the electrical breakdown path will avoid the ceramic particles,and the maximum electric field inside the material will gradually increase,resulting in a lower breakdown strength of the composite material.In addition,a nonlinear relationship exists between the dielectric breakdown strength and the particle size of the filler.The work provides a certain theoretical basis for the design of dielectric breakdown strength of ferroelectric composite materials.

关 键 词：相场模型 介电击穿 铁电复合材料 极化强度 

分 类 号：O34[理学—固体力学]