Role of kinetics in laser processing 1

A computational model has been developed in order to simulate any laser-induced surface modification process with or without the kinetics condition. Front-fixing method with Landau transformation has been used to represent the geometric domain. Spectral collocation method has been utilized for spatial discretization in this model, while backwards differentiation has been used for temporal discretization. The computational model has been applied to the problem of laser-induced melting of an iron sheet with a medium power laser. In order to understand the importance of kinetics of phase transformation, the problem has been solved with and without the kinetics condition at the interface, and the results have been compared. It is observed from the test case that if kinetics condition is not used, the interface location is over-predicted and the free surface temperature is under-predicted. Both of these factors may have important consequences in several material processing techniques such as laser machining, laser annealing and pulsed laser ablation. q1998 Elsevier Science B.V.