Enhanced LASOX cutting with a Yb-fibre laser

Laser cutting is the largest laser material processing technology deployed in modern industries, and the 10.6 µm wavelength CO2 laser is the most used laser source for this process. One advantage that lasers have over conventional thermal cutting processes, such as plasma and flame, is the instantaneous energy transfer, and narrow kerf, which can result in higher cutting speed and therefore lower processing cost. Normally, in the laser cutting process, a minimum focus beam diameter is located on or into the material surface; depending on the laser power density, this leads to melting and vaporisation of the material. A gas jet, coaxial with the laser beam, creates a narrow kerf-channel and flushes away the melted volume of material; but the process becomes less effective as the material thickness increases and conventional cutting using lasers in the 2 to 6 kW power range is restricted to a thickness of less than 25 mm in stainless steel. However, using an oxygen assist gas jet on carbon steel allows thicker material to be cut, since in addition to blowing away the debris the exothermic oxidation reaction can add 25% more energy to the cutting process. Also see AILU newsletter, link below.