Thermochemical modeling of oxygen-assisted laser cutting

A simple mathematical model is developed to relate kerf depth to laser power, laser scanning speed and kerf width during laser cutting. The model is based on a lumped parameter technique in which the overall energy balance is considered. The energy released during the chemical reaction between the material that is being cut and the assist gas is considered for oxygen-assisted cutting. Experiments were conducted using a carbon dioxide (CO2) laser to test the significance of the chemical reaction in the cutting process. The experiments conducted consist of cutting stainless steel using nitrogen as an inert assist gas, and the cutting of stainless steel using oxygen as a reactive assist gas. The cutting data between the two experiments are compared and used to demonstrate the scaling of the mathematical model. Oxygen increases the cut depth significantly compared to when nitrogen is used as an assist gas. (C) 2000 Laser Institute of America. [S1042-346X(00)00401-0]