CLOSED-FORM AND NUMERICAL-SOLUTIONS TO THE LASER-HEATING PROCESS

The laser processing of engineering materials requires an in-depth ana lysis of the applicable heating mechanism. The modelling of the laser heating process offers improved understanding of the machining mechani sm. In the present study, a closed-form solution for a step input lase r heating pulse is obtained and a numerical scheme solving a three-dim ensional heat transfer equation is introduced. The numerical solution provides a comparison of temperature profiles with those obtained from the analytical approach. To validate the analytical and numerical sol utions, an experiment is conducted to measure the surface temperature and evaporating front velocity during the Nd-YAG laser heating process . It is found that the temperature profiles resulting from both theory and experiment are in a good agreement. However, a small discrepancy in temperatures at the upper end of the profiles occurs. This may be d ue to the assumptions made in both the numerical and the analytical ap proaches. In addition, the equilibrium time, based on the energy balan ce among the internal energy gain, conduction losses and latent heat o f fusion, is introduced.