Vortrag (20 Min., 5 Min. Diskussion, 5 Min. Raumwechsel)
Laser based methods are often used to treat the surfaces of different materials for obtaining advanced functionalities. Compared to other technologies laser texturing provides the possibility to treat complex parts in a one-step without requiring post processing. This fact represents a key characteristic, especially for industrial applications in which high precision is required. For reaching high throughputs, and thus reducing processing times and consequently production costs, many investigations have already been performed for optimizing laser process parameters in order to achieve high ablation rates. A possibility that has recently arisen describes the use pulsed laser ablation operating in burst mode, which consist on dividing the laser pulse in two or more sub pulses with separation time of a few nanoseconds. In this way, higher removal rates in comparison to single pulse mode have been reached on different metallic substrates.
In this study, the burst mode is implemented in Direct Laser Interference Patterning (DLIP) for increasing the ablation rate in stainless steel substrates. The main aim is to analyze the effect of the number of burts (sub-pulses) and laser fluence on the structure depth of line-like patterns produced using a two-beam configuration. Finally, preliminary tribological results are introduced for showing the potential of the produced textured surfaces. The morphology of the fabricated structures is analyzed by confocal, scanning electron and atomic force microscopy.