Dielectric breakdown and thermal conductivity of textured alumina from platelets

A textured alumina was fabricated from anisotropic α-alumina particles (platelets) by heating at 1650°C for 15 min under applied pressure of 60 MPa using a PECS (Pulse Electric Current Sintering) technique. Subsequently, the thermal conductivity, mechanical properties and dielectric breakdown of the textured alumina were evaluated, are compared to those of conventional polycrystalline alumina and single crystal alumina. The results showed that the thermal conductivity of the textured alumina could be to exhibit almost the same dielectric breakdown as the conventional alumina, that is, the dielectric breakdown was 15 kV/mm and thermal conductivity was 36 W/mK, when the alumina was cut on the vertical plane in the load direction while sintering.