Electrical Breakdown: Insulator Behavior After High Voltage

[Shakattack12]

Hey guys,

I as wondering what happens to an insulator during and after electrical breakdown. I understand that at a high enough voltage it exceeds the dielectric strength and becomes a temporary conductor. However, what happens afterwards. Is the material deformed or does it still maintain structural integrity?

 

[Lord Jestocost]

Typically, a breakdown channel is formed somewhere in the material owing to local decomposition of the material. As hard breakdown events are generally accompanied by strong local heating effects, the material surrounding the channel can suffer from plastic deformation owing to the sudden generation of high local stress field. For various breakdown mechanism see, e.g.,: https://www.tf.uni-kiel.de/matwis/amat/elmat_en/kap_3/backbone/r3_5_2.html

 

[Dadface]

I think it depends on the medium within which breakdown occurs. Sparking can occur during breakdown and this can permanently damage, I guess most if not all, solid materials. But certain gases can recover, in other words the excited and ionised atoms in the high energy environment of a spark can return to lower energy states after sparking. Not to forget that high temperatures can cause or speed up changes due to chemical and biological reactions.