Energy balance in laser-based free form heading

For the production of microparts having large local accumulation of material a size effect can be used: local melting by pulsed laser heating is used instead of a multistage upsetting process. The principle of this laser free form melting process is described. The influence of pulsed energy on the cumulated volume is investigated by experiments. The efficiency is determined by an analytical model, which gives the basis for an understanding of the relevance of the different coupling and energy loss terms. It is shown that the assumption of an adiabatic process is correct at least as a first approximation and the change of coupling phenomena from anormal to Fresnel absorption can explain the observations.