11
Argon-25% He (HE-25)
– This little used mixture is sometimes recommended
for welding aluminum where an
increase in penetration is sought and bead appearance is of primary importance.
Argon-75% He (HE-75) –
This commonly used mixture is widely employed for mechanized welding of
aluminum greater than one inch thick
in the flat position. HE-75 also increases the heat input and reduces
porosity of welds in 1/4 and 1/2 in.
thick conductivity copper. Argon-90%
He (HE-90) – This mixture is used
for welding copper over 1/2
in. thick and aluminum over 3-in. thick.
It has an increased heat input which improves weld coalescence and provides good
X-ray quality. It is also
used for short circuiting transfer with high nickel filler metals.
Figure 4-4 – Effect of Helium
Additions to Argon
