Process Date: January 2002

A weld created using a Synrad EVO125 laser on copper-nickel foil.

The photo on the left shows the results of welding 0.0025" thick sheets of copper-nickel alloy foil. Using an Evolution ™ 125 watt laser, the weld was made at a velocity of 110 inches per minute with a 2.5" focal length lens having a spot size of 0.004”. Argon gas, at 2 PSI, was used for shielding.

The key to achieving virtually no heat deformation and a uniform weld bead is in selecting proper pulsing parameters for the laser. In this case, a pulse frequency of 685 Hz and a pulse length of 880 microseconds provided the weld characteristics desired. Changing the thickness or width of the weld bead is simply a matter of experimenting with variations in beam velocity, pulse frequency, or pulse length.