weld al6061 and al7005 or al7020

[izeman]

i plan to add a battery box to my bike. those are two different bikes: one is al6061 and the other one is al7005.
we can get some al7020 material to make the box out of. will this be fine so weld to the two frames?
i now that al7005 has to be heat threated to be oxidation resistant and/or let sit for 3 month for full strenght. but welding different aluminium alloys? one with ALSI and on with ZN?
any pro on this topic that can help?

 

[agniusm]

No. Only 7003 and 7005 are weldable. As long as the filler material is suitable for both alloys there should be no problem welding different alloys.

 

[izeman]

what question did you answer with 'no'? i know that all 3 types of aluminium alloy are very good weldable.
the question was: do 6xxx and 7xxx fit together?