Laser Straight Cutting of an Aluminum Alloy: Effect of Cutting Speed on Kerf Size

摘要

Laser straight cutting of 2024 aluminium alloy is carried out using a CO2 laser and the kerf width variation due to laser cutting speed is examined. The lamp parameter analysis is introduced to formulate the kerf width and its variation is predicted in line with the experimental conditions. The predictions of kerf width variation are compared with the experimental data. Morphological changes in the cutting section are examined using and optical microscope and a scanning electron microscope (SEM). It was found that the CO2 laser cut section is free from large scale asperities such as large size cracks and excessive sideways burning. The kerf width predictions agree well with the experimental data and the differences between both results are within the experimental errors. The kerf width size increases at the back surface of the workpiece, which is associated with the beam size enlargement towards the kerf exit, exothermal oxidation reactions, and transient plasma behaviour in the kerf. The regular strain patterns are formed at the kerf surface and locally scattered few small size dross attachments are observed at the kerf edge, which are more pronounced for low CO2 laser cutting speeds.