PVDF基磁电复合材料及其改性机理研究

发布时间：2018-01-06 17:28

本文关键词：PVDF基磁电复合材料及其改性机理研究　出处：《华中科技大学》2015年硕士论文　论文类型：学位论文

【摘要】：磁电复合材料因具有磁电转换功能而广泛应用在滤波器、磁场传感器、换能器、信息存储器等方面,目前已成为铁电、铁磁功能材料领域研究的热点。本文以聚偏氟乙烯PVDF基磁电复合材料为研究对象,采用微结构磁场调控和结构改进两种方法来提升材料的磁电转换性能。本文工作对磁场调控磁电复合材料磁电性能的研究及高性能柔性磁电复合材料的制备具有较好的指导意义。本文首先研究了聚偏氟乙烯PVDF、锆钛酸铅PZT和稀土铁合金Terfenol-D(TD)三相颗粒磁电复合材料中各相含量与复合材料电学性能的关系。考虑材料的柔韧性及电学性能,当PVDF与PZT体积比为3:7时,PVDF/PZT复合材料的综合性能最佳。在此基础上,添加不同含量的磁致伸缩相材料TD并进行磁电转换性能测量,实验结果显示,三相磁电复合材料的磁电转换性能随着TD含量的增加先增大后减小,这是由过低TD导致的磁致伸缩性能差和过高TD导致的渗流而降低压电性能引起的,当TD含量在7vol%时PVDF/PZT/TD复合材料的磁电转换系数达到58mV·cm-1·Oe-1。在磁电复合材料微结构磁场调控方面,本文采用溶液混合和热压成型工艺相结合,通过在热压成型过程中施加不同大小的诱导磁场,制备了PVDF/PZT/TD颗粒磁电复合材料。通过对磁电复合材料的压电性能、介电性能以及磁电转换性能进行分析,探究了诱导磁场对PVDF/PZT/TD颗粒磁电复合材料电学性能的影响。实验结果表明,磁电材料的磁电转换系数随着诱导磁场的增加先变大后减小,这是因为较小诱导磁场能有效提升材料磁致伸缩性能,而较大磁场在提升磁致伸缩性能的同时会较大程度上降低不同功能相间的耦合度从而降低磁电转换性能。磁电复合材料的磁电转换系数在诱导磁场200Oe附近时达到最大值82.5mV·cm-1·Oe-1,比无诱导磁场作用下的PVDF/PZT/TD颗粒磁电复合材料提高了40%以上。在结构改进方面,为了克服颗粒磁电材料中TD含量低的问题,本文制备了三层结构的层状磁电复合材料。根据相关理论分析,把压电层PVDF+PZT作为中间层,磁致伸缩层PVDF+TD作为两边层;为了得到性能最佳的层状磁电复合材料,研究了不同的层厚比对材料各项性能的影响,结果显示,当PVDF+TD、PVDF+PZT、PVDF+TD三层的层厚比为1:1.5:1时,该三层结构材料的磁电转换系数达到最大值2576.2 mV·cm-1·Oe-1,比PVDF/PZT/TD颗粒磁电复合材料增加了44倍左右。0-3型PVDF基磁电复合材料在柔韧性、抗老化、抗腐蚀、高频性能和抗涡流能力等方面优势明显,但其低磁电性能制约着该类材料应用的进一步推广。诱导磁场对磁电复合材料的磁电性能具有较好的提升作用,磁电复合材料的结构模式对磁电性能有着较大的影响,采用微结构磁场调控和结构改进的方法有利于促进柔性磁电复合材料实际应用的推广。
[Abstract]:Magnetoelectric composites with magnetoelectric conversion function which is widely used in filter, magnetic field sensor, transducer, information storage and so on, has become the hot research of ferroelectric and ferromagnetic functional materials. In this paper, polyvinylidene fluoride PVDF based magnetoelectric composite materials as the research object, using the micro structure of magnetic field and structure improvement of two methods to improve the material performance. This paper studies magnetoelectric conversion of magnetic field control of magnetoelectric composite magnetoelectric properties and high performance flexible magnetoelectric composite material preparation has good significance. This paper studies the polyvinylidene fluoride PVDF, lead zirconate titanate PZT and rare earth iron alloy Terfenol-D (TD) three-phase magnetoelectric composite particles the material in each phase content and the electrical properties of the composites. The flexibility and electrical properties of the material in the PVDF and PZT, when the volume ratio of 3:7, PVDF/PZT composite material synthesis Optimal performance. On this basis, the magnetostrictive phase materials with different content of TD and magnetoelectric conversion performance measurement, the experimental results show that the three-phase magnetoelectric composite magnetoelectric conversion performance with the increase of TD content increases first and then decreases, which is caused by the low seepage TD magnetostrictive properties and high difference caused by TD while reducing the pressure caused by the electrical properties, when the content of TD in the 7vol% PVDF/PZT/TD magnetoelectric composite conversion coefficient reached 58mV - cm-1 - Oe-1. in magnetoelectric composite micro structure magnetic field regulation, this paper adopts solution mixing and hot pressing forming technology combined by magnetic field induced by applying different size in the hot pressing process, PVDF/PZT/TD particles magnetoelectric composites were prepared. The magnetoelectric composite piezoelectric properties, dielectric properties and analysis of magnetoelectric conversion performance, explores the induced magnetic field on PVDF/PZT/TD The effect of particle magnetoelectric composite electrical properties. The experimental results show that the magnetoelectric magnetoelectric materials with increasing magnetic field induced conversion coefficient first increases and then decreases, this is because the smaller the induced magnetic field can effectively enhance the magnetostrictive properties of materials, and the larger magnetic field will greatly reduce the degree of coupling between different functions so as to reduce the magnetoelectric conversion performance in at the same time enhance the magnetostriction properties. The magnetoelectric magnetoelectric composite conversion coefficient reaches the maximum value of 82.5mV - cm-1 - Oe-1 in the induced magnetic field near 200Oe, than PVDF/PZT/TD induced magnetoelectric composite particles under magnetic field is improved by more than 40%. The improvement in the structure, in order to overcome the low content of TD particles in the magnetoelectric materials problems. The layered magnetoelectric composite three layer structure was prepared in this paper. According to the theory analysis, the piezoelectric layer PVDF+PZT as the middle layer, the magnetostrictive layer PVDF+T D as both layers; in order to get the best performance of the layered magnetoelectric composites, of different thickness ratio on the properties of the materials, results showed that when PVDF+TD, PVDF+PZT, PVDF+TD three layer thickness ratio 1:1.5:1, the three layer structure material magnetoelectric conversion coefficient reaches the maximum value of 2576.2 mV cm-1. Oe-1, PVDF/PZT/TD particles than magnetoelectric composites increased about 44 fold.0-3 PVDF based magnetoelectric composites in flexibility, aging resistance, corrosion resistance, high performance and anti vortex ability has obvious advantages, but its low magnetoelectric properties restricts the further application of this kind of materials. The magnetoelectric properties of the induced magnetic field of magnetoelectric composites has a good promotion effect, the structure model of magnetoelectric composite materials has great influence on the magnetoelectric properties through micro magnetic field structure regulation and improved structure is conducive to the promotion of soft magnetic composite The promotion of the practical application of the material.

【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB33

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