Ultrashort pulse surface melting and smoothing: The impact of pulse spacing on heat accumulation and structure formation
Fabian Nyenhuis, Andreas Michalowski, Johannes A. L’huillier
Abstract
Ultrashort laser pulses are often used in industrial manufacturing due to the small heat-affected zones they produce and their low melt formation. A contrasting approach aims to exploit the residual heat of successively applied laser pulses in combination with the material response. As a result of the heat accumulation within a burst, the formation of a melt film that is highly spatially and temporally confined is possible. Experiments, theoretical analysis, and numerical heat-flow simulations are used to show the influence of the laser parameters on pulsed melting and surface structure formation. Special attention is paid to the temporal delay between the pulses. A comparison of the process on iron and titanium allows the influence of material properties to be considered.