Microstructure Changes of Nickel-Base Superalloys Induced by Interaction with Femtosecond Laser Beam

The investigation was performed on nickel-base superalloys, with nickel being the most influential alloying ingredient. After thermo-mechanical preparation and corresponding processing, femtosecond laser beam machining has been performed. The laser wavelength was 800 nm. The exposition time, during which the samples have been exposed to the pulses of femtosecond laser beam varied, as well as the average output power. The changes of both the output power and the exposition time enabled the samples to be irradiated with different total energy during each exposition. The changes in samples microstructure were observed with optical and scanning electron microscopy, with energy-dispersive spectrometry, and analyzed as well. Microhardness measurements of both base material and ablated spots have been performed.