An approach to modelling evaporation pulsed laser drilling and its energy efficiency

Laser drilling is a thermal process with relatively low energy efficiency since the material removal mechanism is mostly based either on melting or on vaporization. Aiming at the investigation of the laser drilling efficiency, a theoretical both analytical and numerical study of evaporation pulsed laser drilling is presented. The analysis is based on a linear approximation of the temperature profile and separates the process into three phases, those of the heating, the melting and the vaporization. Based on these models, the energy efficiency and its dependence on the process parameters have been investigated and selection of relevant process variable guidelines, towards improving energy efficiency, are given. Moreover, the physical mechanisms responsible for most of the energy losses are analysed and classified according to their importance.