Investigations of qualitative aspects with burst mode ablation of silicon and cemented tungsten carbide

This paper presents results obtained by studying the micromachining of silicon and cemented tungsten carbide using high-frequency ultra-short-pulsed laser radiation. Depending on the fluence and number of pulses in the bursts, structures were created on silicon and cemented tungsten carbide to be able to determine the surface roughness and the depth of the structures. A single pulse in a burst represents the conventionally pulsed laser radiation (single pulse mode). Depending on the number of pulses in a burst, the achieved depth of the structure ablated increases. In silicon, a significant improvement in surface roughness could be achieved in a certain parameter range using the burst mode. In the case of cemented tungsten carbide, it was demonstrated by energy-dispersive X-ray analysis that the stoichiometry is maintained after processing in burst mode and conversion from composite to surface alloy takes place.