Power factor model for selection of welding parameters in CW laser welding

•An empirical model for determination of weld profiles in keyhole laser welding is proposed.•The model relies on two parameters, which determine the depth and width of laser welds.•These parameters ensure the same depth of penetration with different beam diameters.•This enables achievement of a particular laser weld with different optical set-ups.•The model can be potentially used to transfer welding parameters between different laser systems.

Laser welding offers enormous flexibility in terms of delivered energy. It does however, require a vast amount of parameters and phenomena to be monitored in order to control the process and to ensure high quality processing. In laser welding the same depth of penetration can be achieved using different combinations of parameters, such as laser power, travel speed. The problem is further complicated by the effect of beam diameter, which may vary significantly between different laser systems. In this work an empirical model, which enables achievement of a particular depth of penetration independent of the beam diameter is presented. First, the user selects a weld shape which meets a certain quality requirements and depth of penetration that have to be accommodated and then the model will specify how to achieve this weld using a particular laser system with a particular beam diameter.