Spectroscopic comparison of aluminium welding plasmas produced by high power CO and CO2 lasers

Abstract Welding tests on the aluminium alloy AlMgSi1 (6082) by the use of a high power CO laser with good beam quality show higher penetration depths and better weld seam quality compared with the results obtained with a commercial industrial CO 2 laser. Spectroscopy of the laser-induced welding plasma shows a strong decrease of the intensities of Al(II) lines and no appearance of Al(III) lines in CO laser aluminium welding compared with CO 2 laser welding at the same process parameters. This is a consequence of the shorter 5 to 5.6 μm wavelength of the CO laser leading to reduced beam-plasma interaction.