If you mean the aluminum tubes in the landing gear and plates than the 6061T6 is the common heat treated alloy we use. T6 or T65 is the common heat treatment designation. Usually around 700 degrees the critical point that you do not want to cross if you heat them up or weld them as they will lose the tempering. I am not sure if I was answering your question or not so just ignore it of not!
The question was about Dominator gear (at least this thread is supposed to be about Dominators). I believe that the gear is not heat-treated. It's standard practice to fine-tune it after preliminary assembly, using a welding torch. That practice, of course, draws out any heat-treatment.