Effect of Shielding Gas Pressure in Laser Cutting of Sheet Metals

Abstract

To investigate the influence of the shielding gas pressure on the laser cut quality, a series of experiments was conducted for various cutting conditions. The cutting pressure distribution was measured on the workpiece, and also beneath the workpiece with a prepared kerf for various nozzle pressures and nozzle-to-workpiece distances. The cut specimens were inspected by various manners such as dross observation, surface roughness test, and kerf width measurement. Based on the data of pressure measurements and the results of the cut surface inspection, the influence of the considered cutting conditions on the cut quality could be evaluated. The cutting pressure beneath the bottom surface was slightly different from that on the top surface and the pressures on two surfaces had a substantial influence on the dross state. But they possessed only a negligible effect on the surface roughness and kerf width, except the extreme case, where the cut kerf could not be obtained. It could be also revealed that the cutting pressure, which has a close relationship with the nozzle-to-workpiece distance under a given nozzle pressure, affects the range of the available cutting speed.