Mechanical property evaluation according to alumina content of aged porcelain insulator

High-efficiency power transmission of is gaining importance in modern society. Studies based on the improvement of quality and performance of materials that are used for fabricating high-voltage insulators are being actively conducted. The porcelain insulator has been used in power-transmission facilities for decades because of its excellent insulation and mechanical properties. It is also attracting attention as a potential next-generation high-voltage component because it is made of environment-friendly material. However, the mechanical strength and aging characteristics of ceramic material, because of its composition and microstructure, differ from those of the porcelain material; this makes it difficult to safely manage the product over a prolonged period in the industrial field. Therefore, in this study, field aged insulators are tested to analyze the effect of microstructure on mechanical properties and aging characteristics based on the alumina content of porcelain. The phase is analyzed via X-ray diffraction, and the change in corundum content is quantitatively analyzed via scanning electron microscopy and an image-analysis program. Vickers hardness test and tensile test are performed to evaluate the mechanical properties of the porcelain insulator based on the corundum content, and the failure probability is predicted by Weibull analysis of the tensile load. Finally, the tensile load equation is derived based on the corundum content and aging, and a verification test is conducted to confirm that mechanical strength and aging resistance increase as the corundum content increases.