Welding aluminum to steel?

[sherwood]

I was wondering if anyone had any information on this process, its a common joint in the aircraft industry for fuel systems. I have seen pictures of this but have little or no idea how its done. I bought a henrob 2000 torch (which is really nice and you should check it out) and it gas welds almost any metal and does as nice as tig on aluminum and figured that if anything can join steel and aluminum this would be it. Please leave me any info you have about this process.

Thanks, Patrick

 

[metengr]

I believe what you are referring too is brazing. Typically, aluminum cannot be fusion welded to steel because of the formation of Fe/Al intermetallic compounds that substantially weaken the weld deposit.

There are a number of internet sites that advertise braze filler metals for joining aluminum to steel without the need for pre-coating the steel with aluminum.