Overheated on track - now what?

[infernosg]

Originally Posted by RETed

That's typical.
It's actually aluminum oxide.
It's galvanic corrosion due to having two dissimilar metals (steel side irons + aluminum rotor housings) and an electrolyte (coolant) - that's basically a battery.


-Ted

Gah, of course! In my search to find something I've managed to forget even the most basic material science. So what exactly should I be looking for given the circumstances? I have a couple other pictures of the rear iron and rotor housing but nothing looks out of the ordinary (to me).