The synthesis process of Porcelain Alumina Ceramic Insulator (PACI) material was carried out from various compositions of kaolin, ball clay, feldspar and alumina. The composite samples were prepared through mechanical milling and compaction processes to obtain three ceramic composites C1, C2 and C3. The sintering process on the composite samples was carried out at temperatures of 1200 ^oC and 1300 ^oC for 3 hours. All sample ware tested for morphology, crystal structure, elemental composition using SEM, XRD and XRF as well as compressive strength test and electrical properties. In sample C1, XRD results show that increasing the sintering temperature increases the crystallite size by about 71.65% with the dominant phase being mullite and a little quartz making the ceramic stronger and better as an electrical insulator. Likewise, Increasing the sintering temperature of ceramic composites, especially C3, can increase their strength to around 46.27 MPa with a stable density of around 1.56 gr/cm³, while the combination of kaolin and alumina and sintering treatment also produce good electrical properties, with an optimum dielectric value at C1 of around 9.27 kV/mm. Therefore, the experimental results show that the sintering process at a temperature of 1300 ^oC makes the porcelain insulator stronger and has better electrical properties.

Keywords: Porcelain Alumina Ceramic Insulator (PACI), Corundum, Material strength, Insulating properties.