Heat affected zone in aluminum single crystals submitted to femtosecond laser irradiations

Abstract : An experimental procedure is developed to quantify the radial dimension of the heat affected zone (HAZ) in metals submitted to laser pulses. A cube oriented aluminum single crystal is highly deformed by plane strain compression, then micro-drilled by 200 fs or 8 ns laser pulses, and finally analyzed by the electron back scattering diffraction technique. Recrystallized and recovered zones are observed as signatures of the HAZ. A typical value of 1.5 µm is found in the femtosecond regime of illumination, whereas for nanosecond pulses a value of 25 µm is measured. These results are in accordance with previous experiments and numerical simulations.