摘要
为了对纳米复合电介质的电气性能变化与显微结构之间的关系进行深入研究,以双酚A型环氧树脂为基体,通过机械分散法制备了不同浓度的纳米Al_2O_3-环氧树脂复合电介质。利用扫描电镜对试样的断面进行了观测,研究了不同含量的纳米粒子对复合电介质介电响应和工频击穿特性的影响。结果表明:纳米粒子在环氧树脂基体中分散均匀;随着掺杂量的增加,复合材料的介电常数和低频损耗先下降后上升,在纳米粒子质量分数为1%时达到最低;工频击穿场强先增大后减小,在纳米粒子质量分数为1%时达到最大,为43 400V/mm,相对纯环氧树脂提高约11.8%。分析认为,纳米粒子与环氧树脂之间形成的交互区是影响短时击穿的主要因素。微量掺杂时,交互区的厚度小于载流子的自由程,抑制载流子迁移,进而增大击穿场强,随着纳米掺杂量提高,交互区会发生重叠,降低击穿场强。
To investigate the interrelation ot nano-cmposite performance and microstructure, nanoAl2O3-epoxy composites are prepared by mechanical dispersion method. It is observed by SEM that nanoA1203 particles are well dispersed in epoxy matrix. The effects of nanoAl203 on dielectric response and breakdown of epoxy are studied by dielectric property test and breakdown examination. With the increasing filler loading, the dielectric constant decreases first and then increases, and reaches the lowest when the mass fraction of nanoA1203 gets 1%. The breakdown field strength has the opposite trend： it increases first and then decreases, and reaches the highest value of 43 400 V when the mass fraction of nanoAl2O3 gets 1%, increasing by 11.8% compared with pure epoxy. It is indicated that interaction zone between nanoparticle and epoxy matrix plays an important role in short-time breakdown. When the content of the particles is small, the thickness of interaction zone is less than the carriers＇ free path to block carriers to migrate, so the breakdown field strength increases. When the content increases, the overlapped interaction zone leads a lower breakdown field strength.
出处
《西安交通大学学报》
EI
CAS
CSCD
北大核心
2016年第12期18-23,154,共7页
Journal of Xi'an Jiaotong University
基金
陕西省自然科学基金资助项目(2015JM5243)
