Wonder if there is a clever way to get around the deformation problem...perhaps filling the tube with something to support it maybe?
OK...so I couldn't help but look it up...one of the applications is listed as pipe bending. Think it's basically a low melting point alloy....how you'd get it in there is a different matter but perhaps another easier to obtain material would work just as well.
http://uk.metaconceptgroupe.com/produits/cerro-alloys/
Ive heard of people using sand. I'll look into it