Electric field assembled anisotropic alumina composite for thermal dissipation applications

A composite material with anisotropic microstructure was fabricated by DC electric field. Alumina was used as filler for thermal conductivity and polysiloxane resin was used as matrix. According to the alumina morphology and loading amount, various anisotropic microstructures were assembled. The thermal properties of the composite material were investigated parallel to the direction of the applied electric field accordingly. For plate-like alumina with 20 vol% loading, a thermal conductivity of 0.44 W/mK was achieved. With spherically shaped alumina, with an equal loading of 20 vol%, a higher thermal conductivity of 0.46 W/mK was achieved. The increase in the thermal conductivity of the fabricated alumina composites with anisotropic microstructure was attributed to increased filler-to-filler connectivity.