Controllable Preparation and Properties of Layered Al2O3 / EP Composites.

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. [ABSTRACT FROM AUTHOR]