Thermal conduction effect on molten pool depth in laser-material interaction

This paper analyses the modelling of conduction losses in laser-material interaction. The incoming laser energy is evaluated by means of a non linear system equation which allows to calculate the physical state and the shielding effect of the plasma plume. The conduction losses were in particular evaluated by means of several models in order to understand the applicability of each one in relation to power intensity. Their influence has been tested by means of welding experiments with a 3 kW CO2 laser source, where penetration depths on an AISI 304 stainless steel were measured. Samples were extracted from the weld seams and geometric and microstructure evaluations were performed in order to verify the analytical models. Some of the considered conduction losses models evidenced good predicting capabilities in the range of the investigated parameters.