Aluminum Workshop: Filler wire for 5454 Aluminum plate

Q: I have a fabrication project involving 5454 aluminum plate, and I was told to weld this alloy using 5183 filler wire. Is this correct?

A: If you check any of the charts showing the recommended filler metals for the various aluminum alloys, you will find that 5554 is the recommended filler wire for 5454 parent material because its chemistry is a close match to that of 5454 and it is the best recommendation in all respects.

Filler wire 5183 was developed as a high-strength filler metal for 5XXX alloys, such as 5083, with high magnesium content and high strength. I suppose you could consider using 5356 filler wire to weld 5454 as well. 5356 is also a high-strength filler and is commonly used for welding the high-magnesium-content 5XXX alloys and the 6XXX alloys.

Is there anything wrong with using 5356 or 5183 filler metal to weld 5454 aluminum plate? With the one exception mentioned next, no, there isn't, but there isn't any advantage either. A weld in 5454 made with 5554 filler will be as strong as welds made with 5356 or 5183.

A Characteristic of 5454 Aluminum

It's important to know that 5454 was developed to have a very specific characteristic. Aluminum magnesium (that is, 5XXX) alloys with magnesium content higher than 3 percent, such as 5083, can be susceptible to stress corrosion cracking if they are exposed to temperatures above 150 degrees F. Type 5454 was developed with a relatively low magnesium content specifically to avoid this problem. Many 5454 applications specify this alloy to help avoid stress corrosion cracking. If you weld the 5454 with 5356 or 5183, the 5454 won't be susceptible to stress corrosion cracking, but the higher-magnesium-content weld will be.

Before you use 5356 or 5183 to weld 5454, make sure that the service temperature for your application is below 150 degrees F. If it isn't, be sure to use 5554 filler wire.