I don't know if solder sticks to Aluminium, you could always try though.
I tried soldering some metal together at work the other day, it was either steel or aluminium, but I'm guessing it was aluminium because it was inside a laptop, and laptops are designed to be light.
It didn't work.
I used some No More Nails in the end, the metal I stuck wont budge, and my boss swears by it, could always try some of that.