The primary function of the shielding gas in additive manufacturing is to protect molten and heated metal from the damaging effects of the surrounding air and to provide suitable conditions for the arc during the printing process. The shielding gases protect the print area from atmospheric gases, such as oxygen, nitrogen, carbon dioxide, and water vapor. All shielding gases are available in a range of convenient and cost effective gas supply options. Helium and argon are most commonly used.
Helium has unique shielding gas properties for high speed, high power laser printing/welding, including high ionization potential, producing excellent plasma suppression and high weld/print speeds.
Argon acts as an economic shielding gas that, like helium, does not oxidize and has no effect on the chemical composition of the metals, even in their molten state. Nitrogen, an even more economic alternative, does not oxidize but reacts with certain metals at elevated temperatures.
Our Air Products technical team has extensive applications knowledge in surface/bulk treatment of metals to help additive manufacturers optimize the gas selection, supply mode, and purity for improved part processing.
How does gas affect the quality of my additive manufacturing process?