The effect of assist gases on the quality of edge surfaces of Al-Li alloys cut with a pulsed Q-switched CO2 laser

Abstract

The effect of assist gases (argon or air) on the quality of edge surfaces of aluminum alloys cut with a pulsed Q-switched CO2 laser was experimentally investigated. Sheets of both Al-Mg-Li and Al-Cu-Li alloys with thicknesses of 1.5 and 2.0 mm were cut. It was found that the morphologies of the cut-edge surfaces were significantly different after cutting with argon and air. For the first time, the cutting process was carried out using a laser-plasma mode, when an optical discharge was maintained in an argon flow. At an argon pressure of 0.5 bar, the cut-edge surfaces were without dross and their roughness were significantly lower than that after cutting with a continuous wave laser. Severance energy levels were similar for both laser-plasma and continuous wave cutting modes.