Welding properties with high power pulsed CO₂ laser

As one of the method to improve penetration bead shapes and defects (particularly root porosity), pulsed CO2 laser welding properties has been investigated using 5kW CO2 laser. Power level, pulsed frequency, and duty were varied. From this experiment, it was found that the lower duty pulsed laser beam can form the deeper penetration depth. For example, even if the average power is 2.5 kW with 50% duty, the the same penetration depth could be produced with approximately half speed as CW 5kW could be. Proper region which could produce a weld bead with minimun porosities was 30-60 pulses/cm with lower duty condition.