| abstract |
When processing materials with laser radiation (11, 12), a plasma (14) is formed at high beam powers. Because of its absorption of the laser light, this hinders the energy transfer to the workpiece (10). In order to render the electrons mainly responsible for absorption harmless, helium, which promotes the recombination of electrons and ions, is blown onto the processing point (13).n n n This invention takes the readily available gases CF₄ and / or SF₆ instead of the expensive helium. Together with a filling gas / inert gas, to which they are mixed to less than 25%, they are blown (16) via a nozzle (15) to the processing point (13), where they form strongly electronegative fluorine radicals under the influence of the high temperature which withdraw electrons from the plasma (14). This process can be controlled via the mixture composition.n n n The method described is particularly suitable for metalworking, in particular of aluminum alloys. |