The investigation of the effects on the geometrical and dimensional changing of the work and the cutting parameters in the laser cutting

In this study, dimensional changing and surface roughness were examined, by cutting four different geometrical shapes, on the two different materials. The AISI 304 stainless steel and DIN EN 10025-94 (TS 2162 EN10 025-96) structural steel which were widely used in manufacturing were used. The quicker and more economical laser cutting methods were intended for these materials without applying different processes on a laser cutting machine. For this purpose around 500 work pieces were cut on the laser machine. 4 mm, 6 mm and 8 mm thickness values for the materials were determined. 3000 W, 3800 W and 4400 W laser power; 2300 mm/min, 2700 mm/min and 3100 mm/min laser cutting speed; 3, 3.5 and 4 focal length and 0.50, 0.55 and 0.60 bar gas pressure for the structural steel were selected. 14, 15 and 16 bar gas pressure for the stainless steel material were selected. The 7.5", 5" heads having 1.2, 1.5, 2 and 2.5 mm nozzle diameter were used. Oxygen and nitrogen were used as auxiliary gas. After cutting process, dimensions of the parts (with square, triangle, circular and hexagonal shapes) were checked on a Coordinate Measuring Machine. The effects of laser power, cutting speed, focal point and gas pressure cutting parameters on size were investigated. The effects of cutting parameters on physical properties of the materials were also investigated. Surface roughnesses of the materials were measured.A relationship between geometry size variation and surface roughness was established according to laser power, cutting speed, focus point and gas pressure and the interpretation were performed using Minitab software. Interpretation results and experiments were compared. According to the results, it was seen that there is a relationship between laser power and outer edges while there wasn?t a significant relationship between laser power and cutting speed.Key Words : Laser, focal point, laser power, gas pressure, geometry and dimension.