Analysis and modelling of reactive three-dimensional high-power CO₂ laser cutting

A model of the process of cutting metal with a gas assisted CO₂ laser beam has been derived with the principal objective of understanding the role of manufacturing parameters both from its kinetics and its chemistry. The model considers the cutting front as a surface phenomenon for reaction and absorption. An adjusting parameter, m, is introduced in this model to represent the absorptivity for different materials and different incident angles. The mass diffusion rate at the gas/solid boundary of the cutting front is included in this model to investigate the exothermic heat which will be released at the cutting front during the cutting process. The effects of oxide films, polarization, cut front shape, cutting speed and laser power have been analysed. The tendency of the experimental results from many previous researchers agrees with the prediction of these theoretical results. It is shown that very small levels of impurity in the oxygen would be expected to have a significant effect on the cutting performance.