Does Electrical wire suffer 'wear' from electrons?

[defnk]

Hi all,

First post, hope its in the right forum.

My question is, does copper wire wear out from the movement of electrons? Do the electrons cause deterioration?
Assume in a vacuum (no oxidization etc)

Thanks!

 

[chroot]

Indeed, they do. The effect is called electromigration. You can basically imagine it as electrons pushing metal atoms around when they collide.

Since current flows through DC circuits in the same direction at all times, the collisions can gradually push enough metal atoms out of the way and break the wire.

For normal macroscopic wires, the effect is literally insignificant. For the tiny micron-scale wires in an integrated circuit, though, it's very important.

http://en.wikipedia.org/wiki/Electromigration

- Warren

 

[defnk]

Thanks! Great reply.
Any idea what happens to the lost 'matter'?

 

[chroot]

It isn't "lost," it's just moved around. Think about a river washing sediment downstream.

- Warren

 

[ooberchicken]

Is the effect canceled out on AC because the electrons flow both ways?

 

[Astronuc]

Electromigration seems to be primarily a problem in microcircuits. I don't believe I've of problem in large power lines or power electronics.

http://www.csl.mete.metu.edu.tr/Electromigration/emig.htm

The same problem should occur in AC as well as DC for the same current density and voltage.