Laser pulse heating: Modelling of cavity formation

Abstract

Laser pulse heating of steel surfaces is considered and a non-conduction limited heating situation is modelled using an energy method. A numerical scheme employing a control volume approach is introduced to discretize the governing equations of energy. A laser pulse used in the experiment is employed in the simulations to compare the cavity depth with the experimental findings. It is found that the size of the mushy zone across the solid-liquid interface in the early heating period is larger than that corresponding to later heating periods. Similar behaviour is observed for the mushy zone across the liquid-vapour interface, provided that the mushy zone size differs for both cases. A cavity depth of the order of 1 μm is developed along the axial direction, which agrees well with experiment. The cavity profile in the radial direction follows its counterpart obtained from the experiment.