氧化铝/环氧树脂复合材料空间电荷特性与高温高湿环境下交流电场老化

Space Charge and AC Field Aging in High Hygrothermal Environment of Alumina/Epoxy Resin Composites

通过添加微、纳米氧化铝颗粒,制备了氧化铝/环氧树脂复合材料。研究了不同粒径、不同含量氧化铝颗粒对复合材料空间电荷的影响;同时对试样进行高温高湿环境下交流电场老化,再次测量其空间电荷分布,比较分析氧化铝/环氧树脂复合材料在老化前后的电气特性。实验结果表明,微、纳米氧化铝的掺杂使复合材料在直流高压电场下聚集更多空间电荷,且随着氧化铝质量分数的增加而增加,而纳米复合材料积聚空间电荷的现象比微米复合材料更明显。通过比较空间电荷分布发现常温固化型环氧树脂材料在固化过程中,微米氧化铝颗粒在环氧树脂中会发生明显的沉降现象,从而形成含量差异明显的上、下氧化铝/环氧树脂复合材料。将复合材料在80℃、90%RH的环境和AC 20k V/mm电场强度下,连续老化16h,并测量其空间电荷分布,结果表明纳米氧化铝/环氧树脂复合材料相对于纯环氧树脂、微米氧化铝/环氧树脂复合材料具有更好的抗老化能力。

Micro- and nano-alumina/epoxy resin composites were prepared in laboratory. Theeffects of different particle diameters and contents on space charge of epoxy resin composites wereanalyzed in this paper. The space charge distribution of experimental samples was measured before andafter AC aging in high hygrothermal environment, to reveal the effects of alumina on electricalcharacteristics of composites. It is found that more space charges appeared in micro-composites andnano-composites with the increasing of alumina particles content. The sedimentation phenomenon ofmicro-alumina particles is more obvious in the samples of micro-alumina/epoxy resin composites thanthat in the samples of room temperature curable epoxy resin. The samples of micro-alumina/epoxy resincomposites show different contents of micro-alumina between the up and down layers. Under theenvironment of 80℃ and 90% RH, the space charges were detected again after AC aging at 20kV/mm.It is shown that the withstanding aging ability of nano-composite is stronger than those of neat epoxyand micro-composite.