CO2 laser cutting of Incoloy 800 HT alloy and its quality assessment

In this article CO2 laser cutting of Incoloy 800 HT alloy is studied. The dross ejected from the kerf is monitored and the frequency of dross ejection correlated with the striation frequency. SEM microphotography and measurement of the surface roughness of the cut edges are carried out. International standards for thermal cutting are used to assess the quality of the cut edges. A statistical analysis employing a factorial analysis is carried out to determine the significance levels of the cutting speed, laser output intensity, thickness, and the pulse frequency of the laser beam for the waviness, out of flatness, and overall quality of the cut edges. It is found that the dross ejection frequency is directly related to the striation frequency. The results of SEM microphotography, surface roughness measurement, and the optical method for the striation frequency monitoring are found to be in good agreement. The overall quality of the cut edge improves within a certain range of pulsing frequency, which is ca. 600 Hz in the present case. The results of the statistical analysis provide useful information on the influence of parameters on the waviness, out of flatness, and overall quality of cut geometry.