Three-dimensional laser heating including evaporation - A kinetic theory approach

In laser heating process, energy is transmitted to the lattice site molecules through successive collisions. It is this collision mechanism, which describes the heating model. The present study is carried out to develop 3-D laser heating model including the phase change process. The probability of electron and lattice site atom collisions is considered in the case of conduction heating process while the probability of vacancy and molecular collisions is taken into account when dealing with the phase change process. Consequently, the collision probability of each species is considered when describing the conduction, melting and evaporation processes in laser pulse heating. Since the energy equation resulted is in the form of integro-differential equation, a numerical scheme is introduced to solve the governing equation. The temperature profiles predicted from the present study are, then, compared to the results obtained from the previous study. It is found that 3-D model gives lower surface temperatures as compared to the previous results obtained from 1-D model.