Helium-argon Mixed Gas

Benefits in welding, such as increased heat input and penetration, improved weld bead appearance and fluidity, reduced porosity, versatility.

Typical Compositions and Their Uses:

• Low Helium Content (e.g., 75% Argon - 25% Helium):

  • Good for welding aluminum workpieces.

  • Often used for deeper root penetration and reduced porosity in both MIG and TIG welding.

  • Helium content above 25% may cause arc instability in TIG welding.

• Medium to High Helium Content (e.g., 50% Argon - 50% Helium or 25% Argon - 75% Helium):

  • Ideal for welding thicker materials, especially non-ferrous metals like aluminum, copper, and magnesium, due to increased heat input and penetration.

  • Can significantly reduce porosity in laser welding of high-temperature alloys, with 50% helium often showing optimal results.

  • A 70% helium - 30% argon blend is excellent for mechanized aluminum MIG welding where high speeds are desired for material 10 mm or thicker.

• Tri-Mixes (Argon-Helium-CO �):

  • These mixtures are also common, particularly for welding stainless steel and carbon/low-alloy steels.

  • For example: 90% Helium - 7.5% Argon - 2.5% CO � for short-circuiting and spray transfer welding of stainless steel (low CO � content helps corrosion resistance and high helium provides heat input).

  • 66% Argon - 26.5% Helium - 7.5% CO � for carbon and low-alloy steel welding.