STUDY ON THE TRANSMITTANCE OF PLASMA DURING THE CO//2 LASER CUTTING OF MILD STEEL.

In the present study, the CO//2 laser cutting of sheets of mild steel is examined while varying the cutting speed. O//2 (as a reactive gas) is introduced through a nozzle in the cutting section. In order to examine the effect of plasma on cutting performance, O//2 pressure is varied and the absorption of the He-Ne beam passing through the plasma in a direction normal to the CO//2 beam axis is measured at the same time. It is found that cutting quality improves at a particular O//2 pressure for the mild steel workpiece. The absorption of plasma increases as the cutting speed reduces.