Laser cutting quality assessment and thermal efficiency analysis

Lasers are widely used in industry as cutting tools due to ultra flexibility of the cutting conditions, obtaining high quality end product, quick set up, non-mechanical contact between the workpiece and the tool, and small size of the heat affected zone. In the present study, laser gas assisted cutting process is examined. Statistical method based on factorial analysis is introduced to identify the influence of cutting parameters on the resulting cut quality. International standards for thermal cutting is employed to identify the measurable variables when assessing the cut quality. Kerf width size is presented using scaling laws. Contribution of high temperature oxidation reaction in cutting due to assisting gas is accommodated in the analysis. First and second law efficiencies for laser cutting process are formulated. An experiment is conducted to assess the cutting quality and validate the Kerf width predictions. It is found that increasing laser beam scanning speed reduces the Kerf width while Kerf width increases with increasing laser output power. The main effects of all the parameters employed have significant influence on the resulting cutting quality. First law efficiency increases with increasing laser scanning speed, which substantiates as the workpiece thickness is doubled. © 2004 Elsevier B.V. All rights reserved.