Modeling of separation speed in thick plate cutting with a high-power fiber laser

Abstract

Most laser cutting operations rely on the operator’s experience and reference data tables to complete the material separation work. This traditional method is time-consuming and labor-intensive, seriously restricting the progress of laser cutting technology toward intelligence and automation. To obtain the material separation speed quickly, this work explores a method to establish a mathematical model of the separation speed by theoretical derivation. Firstly, the energy absorption and consumption in laser cutting of thick plates are analyzed in detail. The laser power density, oxidation reaction power density, and energy consumption per unit volume of material during heat conduction, melting, and heating are modeled, respectively. On this basis, the criterion of separation speed is defined. The theoretical model of separation speed is established through theoretical derivation. Secondly, the effects of laser power, gas pressure, focal plane position, material thickness, and nozzle diameter on the separation speed are investigated. A comparison between the theoretical and experimental values of the separation speed reveals obvious differences in both; however, there are consistent trends in their changes with the process parameters within a certain range. Thirdly, the differences between the theoretical and experimental values of the separation speed are analyzed in detail. This work helps to deepen the understanding of the laser cutting process and improve the laser cutting efficiency.