Involving material specific interaction in surface structuring of metallic materials by ultrashort pulsed Direct Laser Interference PatterningThursday (25.06.2020) 11:30 - 11:50 Room 2
Surface structures in the micro- and nanometre length scale have shown to enhance the performance and functionality for many specialized applications in surface engineering. Like in the case of their natural blue prints, e.g. the well-known lotus and shark skin, this positive effect is closely related to precisely designed surface structures, which might also involve hierarchical patterns. In technically achieved surface structures, the morphology of the topography is in complex relation to the utilized processing methodology, by which the material interaction has to be fully understood to enable high quality results. Ultrashort pulsed Direct Laser Interference Patterning has shown to be able to produce surface structures in both the micro- and nanometre length scale in a one-step process on a large scale of solid materials. This is enabled by a mainly ablative material response on ultrashort pulsed laser irradiation, where thermal diffusion plays a minor role even in highly conductive metallic materials. Nevertheless, the detailed response is strongly varying in between materials of even the same class leading to differences in the morphology of the achieved topographies resulting from different ablation mechanisms.
In this context, we present the results of a study, where the material specific interaction in response to ultrashort pulsed Direct Laser Interference Patterning was investigated for the creation of hierarchical structures in the micro- and sub-micrometre scale on and metallic materials. In the experiments, the complex thermal surface kinetics involved in the pattern formation were examined also involving thermal simulation using a Two Temperature Model (TTM), which allowed for precise tailoring of the surface structure’s topographical parameters as well as the creation of optimised patterns in the sub-µm scale.