Of course the high strength aluminums are in a heat treated condition when looking at their highest yield strengths.
Then 6061 is popular with machine shops because it machines well and becaus e it is easily available. It is often welded but it is not the best welding aluminum and it is not the highest strength aluminum. The yield strength i s 50,000. (When aftermarket fabricators say that something is billet they u sually mean machined from 6061.)
And 7075 is famous for strength but it does not weld very well. The yield s trength is 76,000 !
But don't forget about 2024 and it does not weld very well. The yield stren gth here is 67,000.
And so here are some high strength aluminum alloys that are better for weld ing:
2219, yield strength 66,000 2519, yield strength 66,000 7003, yield strength 50,000 7005, yield strength 51,000 7039, yield strength 58,000But each aluminum alloy requires a certain type of filler material for weld ing .