Utilization of zirconia nanoparticles for improving the electrical and physical characteristics of HV porcelain insulating material

The effect of zirconium oxide nanoparticles (NZ) addition on the electrical and physical properties of porcelain insulators over high different sintering temperatures was investigated. Different amount of zirconia nanoparticles (0–8 wt%) was added to porcelain sample that obtained from local raw materials found in large quantities and excellent quality in the Sinai and Aswan (Egypt). Samples were produced by powder technology with compositions of 50% kaolin, 25% feldspar and 25% quartz. The prepared samples admixed with different amounts of zirconia were sintered at different temperatures (1100, 1200, 1300 and 1400 °C) for 2 h. The microstructures of some selected samples were characterized by scanning electron microscopy (SEM). Phase composition of some nanocomposites samples was identified using X-ray diffraction (XRD), to evaluate the thermal, structural and microstructural changes by increasing the concentration of zirconia. The electrical properties of different samples were evaluated by measuring the AC breakdown strength, the relative permittivity ( ε r ) and dielectric loss (tan δ ) at different frequencies at room temperature. A finite element method (FEM) axisymmetrical model of the samples is used to evaluate their breakdown strength. The results obtained revealed that, samples sintered at 1300 °C give the best electrical and physical properties. Also, nanocomposite porcelain sample admixed with 4 wt% zirconia nanoparticles and sintered at 1300 °C present the maximum density (3.678 g/cm 3 ), minimum water absorption (0.031%) and minimum porosity (0.049%) values as well as good insulating characteristics and confirm the electro technical porcelain production feasibility.