Surface flashover of alumina insulators in vacuum under impulse voltage (the influence of additives)

This paper investigates flashover performance of alumina insulators prepared with different additives in vacuum under an impulse voltage. The four kinds of alumina insulator studied are prepared under the same sintering conditions with different additives. The surface flashover performance of these samples is tested in vacuum. The microstructure of the alumina samples is also observed using scanning electron microscopy (SEM). Based on the experimental results, the characteristics of flashover are different from the test samples. The analysis shows that the influence of additives may be attributed to the change of microstructure.