Aluminum HAZ properties 1

[LeonhardEuler]

Why do certain filler metals affect the parent metal strength more than others? Example 6061T6 with 4043 filler is weaker than with some other fillers such as 5356

 

[metengr]

Parental metal or base metal strength is unaffected by weld metal selection, and is only affected by heat input from the welding process. The weld joint strength is affected by weld metal selection, and welding process.

 

[LeonhardEuler]

If you check the aluminum manual it shows that 6061 has a lower strength when being welded with 4043 rather than 5356 by about 4ksi on yield if the material is greater than 0.375" thick

 

[metengr]

Yes, that is joint strength and not base metal strength. The weld strength difference is because of the filler metal strength differences.

 

[LeonhardEuler]

No, you're misunderstanding what I am saying. The parent metal is being reduced in strength depending on the filler alloy used. It is shown clearly in ADM that the parent metal strengths in the HAZ depends on the filler alloy used. This has nothing to do with the weld strength. Parent metal strength

 

[metengr]

Most likely ADM is referring to the weld fusion zone of the parent metal, which is where dilution occurs between the parent metal and weld filler metal thus affecting strength.

 

[LeonhardEuler]

Ok, so why does 4043 affect the strength greater than 5356

 

[dik]

...maybe a lower heat of fusion and smaller HAZ.

Dik

 

[metengr]

https://www.thefabricator.com/article/consumables/choosing-the-right-aluminum-filler-alloy

 

metengr is correct; HAZ properties are strictly a function of the thermal cycle.

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

 

[LeonhardEuler]

Ok I guess I just don't understand why the ADM is limiting 6061-T6 base metal strength based on filler alloy. I guess the 4043 requires a higher temperature?