Ultrashort pulse laser micro polishing of steel – Investigation of the melt pool depth
Martin Osbild, Andreas Brenner, Leon Röther, Johannes Finger
Abstract
For the most demanding applications in mold and tool manufacturing, ultrashort pulsed laser structured surfaces sometimes do not meet the requirements for surface roughness. A subsequent polishing step in the same machine with the same beam source offers a time and cost effective solution. The novel approach of ultrashort pulse laser polishing with a pulse duration of τ=10 ps is investigated experimentally and theoretically in the present study. It is shown that a low micro roughness is achieved with a melt pool depth between 1 and 3 µm in hot-working steel 1.2738, which allows a polishing process for surface structures with small and fine geometry features without influencing the structure itself.