Materials
Best welding process for aluminium?
Quick answer
The best process for aluminium is AC TIG for quality, MIG with a spool gun for speed, 1.6 mm+ only — chosen for how the metal conducts heat and what contamination costs you.
Why
Oxide melts at ~2000°C while the metal underneath melts at ~660°C — cleaning and AC balance are everything
Runner-up options
Process choice is really about the job: thickness, position, cosmetics and what machine you already own. The above is the default quality answer; adjust for production speed (MIG) or site conditions (stick/flux-core) as needed.