Welding aluminum

[jwmay]

I've often been told you can't weld steel to aluminum. Today I discovered evidence this is just untrue.

 

[macardoso]

hmmmmm. I'm not a welder, but I wonder about galvanic corrosion with the now mixed metals? I'm also not sure what the "alloy" is that gets made in the weld puddle. If you got hot enough to melt the steel, you'll have some sort of aluminum-iron alloy in the puddle. If only the aluminum melted then I guess it is more of a braze.

 

[jwmay]

No need to worry. It's been "re-engineered" to all steel. I don't imagine it's been in service for longer than 13 hours. I watched a couple different guys try to break it though, and it held up.

 

[Ulma Doctor]

aluminum and steel will not mix under normal conditions.
the aluminum and/or steel may have melted, but didn't likely form an alloy
there is a process using explosives that will adhere dissimilar metals such as aluminum and steel
short of that, i think the bolts gave the assembly any kind of strength

 

[Tim9]

Ulma Doctor said it well. Sure, you can melt both metals and they will “puddle” together. But in the sense of the word “weld”… what you have is not a true weld. You’ve just melted both metals. Good luck having that stand up to abuse .

 

[jwmay]

Sure, you can melt both metals and they will “puddle” together. But in the sense of the word “weld”… what you have is not a true weld. You’ve just melted both metals. Good luck having that stand up to abuse .

I think you're playing a little fast and loose with the word "you". Haha
I didn't make that abomination. I just found some other yoohoos "repair", while trying figure out why the machine destroyed one of its sensors. As for why it was done in the first place, I doubt we'll ever know. We are experiencing no shortage of suitable chunks of steel. Sometimes a person finds an overly craptastic repair, and the reason ends up being that we just didn't have a better option at the moment it was needed. But this garbage was above and beyond wrt useability, design, execution, and durability. Just a fail on every level. But still...like I said...we tried to break it, and it wouldn't. That's how it ended up memorialized on the hallowed pages of the HM forum.

 

[MrCrankyface]

I've sometimes used aluminium as backing when I've welded/filled gaps and just one of the materials melting into the pores of the other can create an incredibly strong bond.
I imagine it's somewhat similar to how soldering works albeit obviously unpredictable and much weaker.

 

[rwm]

That sure looks like someone tried to weld it. Do you think the filler is steel?
Robert

 

[jwmay]

I think they picked up the first piece if junk they found at the welding table, and MIGed it. Nobody uses anything but the MIG. We only have one guy that "knows" how to run the multi process machine, and NOBODY is gonna use the torch for anything but heating up stuck stuff.

 

[rwm]

I could see the MIG gun making holes/pits in the aluminum and filling them with steel. You might get a mechanical bond that way that would be hard to pull apart.
Robert