Welding Tips and Tricks

I am in Aerospace and welding C355 cast aluminum. we have gone through some changes in the molding and ingot process.
I am now getting porosity between the cast surface and the weld puddle. using a dynasty 400 was using a syncrowave 350lx. I know the syncro will have a different wave and the dynasty cant make the exact output. A transformer and a inverted are different, I use a burr to clean, acetone, and oven heat to 300 deg F. ist really a 50/50 shot. Everything is X-rayed and penetrant. Argon and helium mix, zirconiated, E03, Ceriated, lanthanated, getting the same result.

Any guess? could the help. Cheers fellas, Don

Duplicate

Is the problem common to both machines ? Try another bottle of gas from a different source ?

Is the porosity problem common to every casting from the new process or intermittent ?

Can you get a mass spectrometry analysis of the chips you grind off the casting to check the cast material is to the correct material spec and hasn't acquired / lost some elements during the process, also the filler material, if it is a new supplier or batch.

If the Dynasty is set to 60 Hertz and Sine output, it should be close to the waveform of the Syncrowave.

I would look hard for Argon leaks.

I would be suspicious of the casting. Grind into one or X-ray it before you weld. You might just be discovering a problem that’s there before you even weld. Also possible that there is something trapped in the pores of the casting that’s vaporizing and causing bubbles when it gets hot enough to liquify the metal.