Fundamental investigations of burst pulse laser ablation on WC-Co composites

The increasing prevalence of high-power ultra-short pulsed laser systems necessitate the efficient use of energy for high-throughput processes. A promising approach involves the utilisation of ultra-short burst pulses, characterised by intra-burst rates in the MHz and GHz ranges, including their combination as Bi-bursts. These burst modes offer significant advantages over single-pulse methods, including enhanced ablation efficiency, superior surface quality, and controlled melt dynamics. In this study, cemented tungsten carbide was irradiated with various burst modes to investigate process efficiency, productivity and the resulting topography in relation to temporal energy distribution and burst pulse numbers. The results were compared with those obtained in single-pulse mode, revealing significant benefits in both productivity and quality. Following the initial ablation, an additional irradiation was conducted using the GHz-burst mode by varying the number of scans and burst pulses, which further reduced surface roughness by smoothing the topographies generated during the initial ablation.