Check out the online catalogs of McMaster-Carr
www.mcmaster.com , and MSC Industrial Supply
www.mscdirect.com. Both companies have a wide assortment of exotic epoxies, such that you're likely to find something that will work.
I recently read about this stuff: Pyro-Putty™ 657 is a stainless steel filled 1-1 mix, high performance epoxy good up to 400~450°F with a shear strength of 1860psi. Although designed for cast iron and steel, I'd imagine it would work on aluminum. See them
www.aremco.com