Cutting aluminum with plasma
One of our most frequently asked questions revolves around cutting aluminum with plasma. Plasma cutting works for any material that conducts electricity and modern plasma cutting technology yields excellent results on aluminum.
Aluminum cutting requires different gasses and consumables than steel cutting. High-def steel cutting typically uses oxygen as the primary gas and compressed air as the secondary. Standard-def cutting uses air and air for both primary and secondary. When cutting aluminum, the cutting gas (primary) is nitrogen and the shield (secondary) is water. We use nitrogen to make oxide-free weld-ready cuts and water (converted to a mist) to act as a shield. Using water instead of an expensive shield gas reduces cutting costs. Special application require argon or F5 (95 percent nitrogen/5 percent hydrogen).
Hypertherm utilizes Vented Water Injection (VWI) on their high-definition XPR300 plasma cutter. Thermal Dynamics has Water Mist Secondary (WMS) on their standard-definition Auto Cut 200 and 300 and high-definition Ultra-Cut plasma cutters. A high definition plasma cutter paired with AutoGas will typically generate the best edge on steel, stainless steel and aluminum, but excellent results can be had using standard-definition to cut aluminum. Some people are under the impression that plasma cutting aluminum leaves lots of dross that is difficult to clean. You’ll have weld-ready almost dross-free cuts with correct settings.
Cutting aluminum is really no different than cutting steel, with one exception: hydrogen gas builds when molten aluminum mixes with water. Hydrogen can collect under the work plate on water tables, which creates a very hazardous condition. Drop the water level to no less than 2″ below the bottom of the plate to let the hydrogen escape. If you’ll be cutting large amounts of aluminum, we can install a table-length aeration/bubbler system, which uses compressed air to agitate the water and release the hydrogen.