Femtosecond laser machining characteristics in a single-crystal superalloy

Femtosecond laser machining characteristics of a nickel-base single-crystal superalloy were investigated as a function of laser fluence and the number of laser pulses. The significant decrease of recast layer for femtosecond laser machining was observed compared with that for nanosecond laser machining. The ablation thresholds for 1, 10, and 100 femtosecond pulse exposure were measured. Two ablation regions of the ablated crater were observed. The change of the ablation diameter and depth depended on the laser fluence and the number of laser pulses. And higher laser fluence could enable a faster rate of laser-machining.