Once again, NO NO NO... Aluminum is not something you want to cool abruptly and un-evenly.
The odds of the company in China knowing the composition of the metal are also pretty slim. Even if they did know, they probably wouldn't tell you; not a trade secret or anyting but they might not want the level of impurities known. You're pretty much boned if you just want to strengthen the fins, it's okay if they're bent. If you want to straighten them heat them individually with a torch and lightly bend them back with needle-nose. The best temp to bend Aluminum of unknown composition is 400-500 degrees F.