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yes, why the hell not? isn't it as sturdy as, say, steel? maybe not; I don't know!!
but not a bad idea!!!!!!!!
Most people should go with tin foil. That's about the length of the vow and the length of the marriage.
Isn't the idea to have a band made from a precious metal like silver, gold or platinum? (I've even seen titanium.)
Given that, aluminum is considered to be a fairly common metal, these days. There was a time before electricity (literally before electricity as the bauxite-to-aluminum smelting process take a LOT of electricity; first major aluminum smelter was built near the Niagara Falls power plant) when that metal was considered to be precious, the Washington Monument was actually topped off with it when it was first built.
But you can still have a ring fabricated from it if you like. You're probably going to want to have it coated with another material though. Constant skin contact with aluminum will leave a nasty looking black residue.