LASER PERCUSSION DRILLING ON THIN MILD STEEL SHEET BASED ON THE DUTY CYCLE VARIATIONS OF A PULSED RF SLAB CO2 LASER

In this work, the influence of laser pulse trains on thin mild steel sheet blades is investigated. The method is based on varying the duty cycle (DC) of a pulsed RF slab CO2 laser during the process of laser percussion drilling. Here, an experimental methodology to correlate laser parameters and their effects on the characteristics of the melting material ejected was carried out. In the experiments, the interaction time such that of 5%, 10%, and 15% DC were considered for the pulse trains. Results showed a significant effect on the characteristics of melt material ejection during laser percussion. We demonstrate that it was not evident the influence and molten material for pulse width of less than 500 μs and larger than 4500 μs, respectively, when having 5% DC; spatter formation (droplets) for 10% and 15% DC with pulse periods > 2000 μs; debris formation (re-solidified material) at pulse periods from 200 to 1250 μs at 15% DC.