The Effect of High Power Adjustable Ring Mode Fiber Laser for Material Cutting

In this Master of Science Thesis is researched Corelase Oy's performance of ARM fiber laser source’s in laser cutting with different metals. The cutting quality was measured with surface roughness values and cutting edges angularity. The theoretical part covers the principles of the fiber laser, CO2 laser, disk laser and Nd: YAG laser and how they apply to in laser cutting. Also, there is introduction to laser cutting and how the cutting quality can be measured and validate along standard SFS-ISO EN 9013. The test materials were copper, aluminium, mild steel and stainless steel. The copper was tested in 6 mm, 10 mm and 20 mm in thicknesses. The aluminium was tested at 15 mm and 20 mm thick plates. The mild steel had 5 mm, 15 mm and 20 mm plates and the stainless steel had 10 mm and 15 mm thick plates. The experiments were made with one test setup where were used ARM fiber laser source with the output powers of 2+6 kW and cutting head from Precitec. The study focus to find parameters sets which give metals good surface roughness value and to lower the dross formations under the cut edge. Also, the kerf opening angle was measured for 15 mm and 20 mm thick plates which had the best surface roughness. The most effecting parameters to the surface roughness were the feed rate, the focal plane’s position and the nozzle diameter with the assistant gas pressure for all materials. For the mild steel (5 mm and 15 mm), the copper and the stainless steel were achieved the quality class of two for the surface roughness with the ARM laser. For the aluminium and the mild steel (20 mm) achieved the quality class level three. The burr get most effect from the nozzle diameter and the gas pressure. The tests show that the ARM fiber laser source provide good cutting quality with only one type of cutting head. The ARM laser source is versatile what comes to laser cutting