Special Welding Techniques
Section 5
Shielding Gas for Aluminum
Shielding gas for arc stud welding and drawn-arc capacitor discharge stud welding is generally argon of at least 99.95
percent purity. Helium may be used with large studs to take advantage of the higher arc energy (required for magnesium).
The gas should be directed to the weld area with an adaptor foot, and permitted to flow only while the weld tool is held
against the work in the welding position. Generally, 10ft
3
/hr (9l/min) is a good starting point for gas flow; however, the
shielding gas flow rates recommended by the stud manufacturer should be used.
Other Materials
On a moderate scale, stud welding is being done commercially on various brass, bronze, nickel-copper, and nickel-
chromium-iron alloys. These applications are usually very special ones requiring careful evaluation to determine suitability of
design.
Nickel, nickel-copper, and nickel-chromium-iron alloy stud welds tend to contain porosity and crevices. The mechanical
strengths, however, are usually high enough to meet most requirements. The weld itself should not be exposed to corrosive
media.
