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

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.