Why is helium added to argon when making some spray or pulsed-spray transfer welds?

When it comes to welding processes, the addition of helium to argon serves multiple purposes that enhance the overall welding quality. One of the primary reasons for incorporating helium into the welding gas mixture is to boost heat conductivity. While argon is commonly used in welding due to its inert properties and ability to create a protective atmosphere, it has relatively lower heat conductivity compared to helium.

Helium, on the other hand, possesses excellent heat conductivity properties. By introducing helium into the gas mixture, the heat conductivity during the welding process is significantly increased. This enhanced heat transfer plays a critical role in improving the quality of the welds and ensuring proper fusion between the metals being joined.

Furthermore, the addition of helium to argon also helps in encouraging matter dispersal during welding. When helium and argon are mixed, the gases diffuse and form a solution where the atoms of helium and argon occupy a larger volume than they did before mixing. This increased matter dispersal aids in creating a more uniform and consistent weld, especially when dealing with easily oxidizable metals or processes sensitive to air.

Moreover, the helium and argon mixture provides a larger protective atmosphere around the weld area. This expanded coverage helps in shielding the welding zone from external contaminants and atmospheric elements that could negatively impact the welding process. The protective atmosphere created by the helium-argon mixture contributes to better weld quality and effectiveness, particularly in scenarios where precise and controlled welding conditions are crucial.

Conclusion

The utilization of helium in conjunction with argon in some spray or pulsed-spray transfer welds offers a range of benefits that directly contribute to improving the welding process. From enhancing heat conductivity and promoting matter dispersal to providing a more extensive protective atmosphere, the helium-argon gas mixture plays a vital role in optimizing weld quality and efficiency. Its application is particularly advantageous in welding situations involving easily oxidizable metals or processes sensitive to air, where maintaining a controlled welding environment is essential for achieving successful outcomes.