Significance of structure-property relationship in alumina based porcelain insulators to achieve quality

The catastrophic failures of porcelain insulators in power lines can be minimized by understanding the structure-property relationship that governs the performance. A study addressing the materials aspects has been conducted on alumina based porcelain insulators used in 25 kV railway traction lines. This article asserts the controls exercised by chemical composition, crystalline structural phases and microstructure on the functional reliability and durability of the insulators. Influences of the total alumina, α-Al2O3 (corundum) and α-quartz contents, microstructural features including morphologies of mullite needles, quartz and corundum grains in the alumino silicate glassy matrix, large inhomogeneities in matrix constituents and composition have been highlighted.