Measurement and assessment of surface roughness for optimisation of laser cutting technology

Abstract

This paper presents an original approach for the optimisation of laser cutting process based on surface topography measurement. The surface roughness carries important information for monitoring of the immediate state of the technological process, material properties and interaction between a laser beam and machined material. A mathematical model was developed, where the surface roughness was taken into account as the most important quantitative criterion for process optimisation. In this investigation, low carbon steel and stainless steel were cut by using a 5 kW carbon dioxide laser. A Talysurf CCI 2000 and Surftest SJ401 measuring instruments were used for the measurement of the surface roughness. In the study, the average surface roughness Ra was considered. The predicted values for optimisation process conditions were in good agreement with experimental data. By applying the surface roughness model, the optimal cutting parameter setting, minimising surface roughness, was determined.