Laser cutting of aluminum alloys under conditions of formation of an optical discharge in argon jet of pulsed CO2 laser

The article reports on the results of laser cutting of aluminum alloys by a new method, whereby the material is influenced simultaneously by the laser radiation and the optical discharge plasma generated in an auxiliary gas flow. Cutting was carried out in argon flow with the use of pulsed CO₂ laser with modulation of the quality factor at the pulse repetition rate of 40 kHz. The method allowed one to obtain a quality cut without burrs and with low roughness while significantly reducing the pressure of the auxiliary gas (up to 30 times less) when cutting 1.5 and 2 mm thick aluminum alloy sheets. During the tests on low-cycle fatigue, the sample cut by a pulsed laser in the presence of the optical discharge withstood 2.6 times more stress cycles than the sample cut by a continuous laser.