Welding 6061-T6 to 6063-T6

By OhioLou Date 09-08-2003 17:09

I am asking this question at the risk of being kicked of this forum as an absolute rookie.

I want to make the dissimilar metal weld mentioned in the subject. I note that the recommended filler metals for both are the same. I saw a reference somewhere (can't find it) that indicated 6061 had a 15% higher heat conductivity than 6063. Don't know enough to know if that is a problem.

So the question: Is there a generic weld procedure available for making this dissimilar metal weld?

I'm thinking there might be three categories of answers:
1) No problem, here's the procedure that's bullet-proof
2) Some issues with this, but under these conditions can be done, watch out for this.
3) Can't be done reliably.

Any insight would be appreciated.

Lou

By aircraft (**)

Date 09-08-2003 23:45

You won't have a problem.

By mkulikow (*)

Date 09-10-2003 12:02

6063 and 6061 are in NO way dissimilar. Both are Al-Mg-Si, I believe that 6063 has a lower silicon and magnesium content making it a little easier to extrude but a little less strong. You can weld these 2 metals together all day long but understand the weakest link theory and the fact that you will loose half of your strength from the T6 temper in welding. You can use 4043 filler for better wetting out or use 5356 for better strength. Either way you can expect less that 15ksi yield strength post weld without any post weld heat. If you heat up post weld do not use 5356 since its only rated to 1200 degrees or so. You can use 4643 for that. All of the information can be read at:

http://www.weldreality.com/aluminumalloys.htm

- Mike