Drilling model for /spl mu/s-pulses

This work describes advances in fundamental physical modeling, experimental diagnosis as well as time varying processes like drilling a prescribed hole shape. The present model allows to estimate the beam- and pulse shape, that lead to almost complete melt ejection and suppression of resolidified layers at the wall. The corresponding procedure has been patented. The laser drilling process is represented mathematically by a three-dimensional free boundary problem for the motion of two phase boundaries, namely, the solid-liquid and the liquid-vapor boundary. To reveal the structure of the solution and to avoid an unnecessary degree of complexity the iterative extension and refinement of the model is guided by experimental diagnosis