|
 |
Choosing Aluminum Wire by Lincoln's Aluminum Expert,
Frank Armao
Frank Armao |
Within the walls of The Lincoln Electric
Company are some of the brightest minds in welding, but we wouldn't be The
Welding Experts® if it weren't for the expertise of our customers. Learn
with us from questions submitted by real customers and answered by the real
experts. |
When should I use 4043 and when should I use 5356?
4043 is designed for welding 6xxx series aluminum alloys. It may also be used
to weld 3xxx series alloys or 2xxx alloys. 4043 has a lower melting point and
more fluidity than the 5xxx series filler alloys, and is preferred by most welders
because it "wets and flows better" and it's less sensitive to weld cracking
with the 6xxx series base alloys. 4043 can also be used for welding castings.
4043 also makes brighter looking MIG welds with less smut because it doesn't
contain magnesium. 4043 gives more weld penetration than 5356, but produces
welds with less ductility than those made using 5356. However, 4043 is not well
suited for welding Al-Mg alloys and should not be used with high Mg content
alloys such as 5083, 5086 or 5456 because excessive magnesium-silicide (Mg2Si)
can develop in the weld structure to decrease ductility and increase crack sensitivity.
(One exception to this rule is 5052, which has a low magnesium content.)
5356 wire has become the most commonly used of all aluminum filler alloys because
of its good strength and its good feed-ability when used as a MIG electrode
wire. It is designed to weld 5xxx series structural alloys and 6xxx series extrusions,
basically anything other than castings, because castings are high in silicon.
Its one limitation is that 5356 is not suitable for service temperatures exceeding
150 degrees Fahrenheit (65 degrees Celsius). The formation of Al2Mg at elevated
temperatures at the grain boundaries makes the alloys prone to stress corrosion.
For components that will be anodized after welding, 5356 is recommended over
4043, which turns jet black when anodized.
|
|
