| High-voltage porcelain insulators are subjected through a series of ‘simulation’ and ‘accelerated aging’ tests in order to minimize the chances for line failure. Failure analyses conducted in the laboratory indicate that the damages are generally due to (i) local melting and evaporation of materials from the grain boundary matrix and (ii) propagation of inherent flaws, e.g., voids, microcracks in the microstructure arising out of transient electrical and mechanical load factors. A consistency in the raw material quality, a closer in-process quality control and a well-designed microstructure may hold the key to the solution. Issues related to non-destructive testing have been discussed and future R&D opportunities have been highlighted. |
