Ionisation Energy Reduction by Argon-Helium Mixtures
The physical modification of the plasma column by adding helium to argon, which increases the voltage required for charge carrier exchange and generates a higher-energy, broader temperature profile in the arc. This leads to improved heat input into the base material.
Use argon-helium mixtures when you need more heat in the arc than pure argon. Helium makes the arc hotter and wider, which helps with thick plates or highly conductive materials like copper or aluminum. The higher heat input improves melting and reduces the risk of lack of fusion. But be careful: with helium, the arc becomes more aggressive and the weld bead can become flatter. Start with a lower helium addition and increase it only when you see the base material melting cleanly.