What type of materials benefits most from the use of helium gas in welding?

The use of helium gas in welding is particularly beneficial for heavy, thicker materials. Helium provides a higher thermal conductivity compared to argon, which allows for deeper penetration into thicker materials. This is essential when welding heavy sections, as the weld joint requires sufficient heat to achieve proper fusion and strength. Additionally, helium can create a hotter arc, which can be advantageous for achieving good fusion and reduce the risk of defects in the weld bead.

While thinner materials may not typically require the high heat that helium provides, and lightweight alloys may benefit from other shielding gases that offer different characteristics, the ability of helium to generate higher temperatures makes it the preferred choice for welding thicker materials. Plastic composites, on the other hand, are not typically joined using traditional welding methods that involve gas shielding, as they require different techniques suited to their material properties.