Laser structuring of open cell metal foams for micro scale surface enlargementThursday (25.06.2020) 15:40 - 16:00 Room 2
Nowadays, innovative materials gains an increasing market share in several industrial fields. One of these novel materials are open cell metal foams. Those can be found in different industrial applications such as in batteries, implants or chemical filters , since high surface to volume ratio are needed. However, a further increase of this ratio can further improve the functionality of these products. In the past, laser technology highlighted the solution for various challenges concerning the improvement of open cell metal foams [2, 3]. These challenges can be further improved using laser based fabrication methods allowing the production of repetitive periodic structures in the micrometer or sub-micrometer scales, such Direct Laser Interference Pattering (DLIP). Thus, modern laser technologies represent a powerful tool to enhance the surface area of substrates by the generation of ordered surface structures [4, 5].
In this work, DLIP was utilized for structuring the surface of open cell steel foams (Figure 1a). By controlling the laser parameters as well as the geometrical arrangement of the beams, 5.2 µm deep structures with a spatial period of 5.8 µm were fabricated (Figure 1b). Furthermore, despite the fact of an uneven surface, a homogenous pattern could be created leading to an increase of the surface area. Finally, the ability of generating hydrogen in both non-treated and laser textured foams is evaluated. The topography of the used materials was characterized using scanning electron microscopy and confocal microscopy. Moreover, the DLIP-structured foam was electrochemically characterized by determining of the double-layer capacitance using cyclic voltammetry (CV) as well as electrochemical impedance spectroscopy (EIS).