Argon-Helium Shielding Gas
Argon-helium mixed gas increases ionization energy and thermal conductivity of the arc, improving penetration on highly conductive materials like aluminum and copper.
Physicochemical Mechanism of Action
Argon-helium mixed gas contains argon (approx. 75%) and helium (approx. 25%). Helium increases the ionization energy of the arc, while argon increases thermal conductivity. This results in a stronger and more effective penetration.
Metallurgical Relevance & Risks in Welding
For highly conductive materials like aluminum and copper, the mixed gas can improve penetration, enhancing weld quality. However, incorrect concentrations or lack of use can lead to insufficient penetration, resulting in porosity and low weld strength.
Workshop Practice & Instructions
Use argon-helium mixed gas for aluminum and copper alloys. The typical concentration is 75% argon and 25% helium. Ensure the gas is correctly supplied in the weld zone to achieve optimal penetration.