采用冰模板法构筑具有层状结构的Al2O3三维网络骨架, 并通过真空浸渍工艺制备出Al2O3/环氧树脂(EP)复合材料。研究了楔形硅橡胶角度、浆料固相含量、冷冻温度对层状Al2O3三维网络骨架微观结构的影响, 分析了片层间距对Al2O3/EP复合材料导热、介电和绝缘性能的影响。结果表明: 楔形硅橡胶角度为10°和15°时Al2O3三维网络骨架的层状有序性最佳, 固相含量的增加和冷冻温度的降低均会使片层间距减小; Al2O3/EP复合材料的热导率和介电常数随着片层间距的减小而增大, 但体积电阻率呈降低趋势; 当片层间距为45 μm时, 热导率达到0.52 W/(m·K), 体积电阻率为1012 Ω·cm。

The Al2O3 3D network skeletons with layered structure were constructed by ice template method. The epoxy (EP) was successfully infiltrated into the pores of porous Al2O3 material by vacuum impregnation process, and finally the Al2O3/EP composites were prepared. The influences of wedge silicone rubber angle, slurry solid content and freezing temperature on the microstructure of layered Al2O3 3D network skeleton were investigated. And the influence of the lamellar spacing on the thermal, dielectric and insulation properties of Al2O3/EP composites was analyzed. The results show that the order of layered Al2O3 3D network skeleton is the best with the wedge silicone rubber angle of 10° and 15°. Simultaneously, the lamellar spacing in the Al2O3 3D network skeleton decreases with the increase of solid content and the decrease of freezing temperature. The thermal conductivity and dielectric constant of Al2O3/EP composites increase with the decrease of the lamellar spacing, but the volume resistivity shows a decreasing trend. When the lamellar spacing is 45 μm, the thermal conductivity reaches 0.52 W/(m·K) and the volume resistivity is 1012 Ω·cm.