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aluminium butt welds

by andy

any information on butt welding LM6 to 1200 aluminium in 8mm thick plate and LM6 to 1200 need to know weld prep ,rods, pre heat etc etc as im struggling to pass weld test.thanks andy



here are a few tips that should help...keep in mind, that usually on a welding test, the filler metal, preheat, and prep are specified.

from the composition of your 2 alloys, it would seem that 4047 would be best. 4043 should also work fine but since your Lm6 alloy contains about 12 percent silicon, the 4047 rod does also and would flow at a lower temp and also has less a tendency for cracking and porosity. there are some strength differences but you didnt mention that requirement.

a preheat of about 200 f will help

for your prep, stay away from scotchbrite, use only stainless wire brushes, use only a clean file if possible to prep the weld surface,
wipe with acetone before you start the prep and right before welding...let all the acetone dry before welding.

here is the most important tip...I have been working a lot lately with porosity issues on aluminum and have found that 80/20 helium/argon mix helps more than any one thing.

good luck bro,


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