Abstract:
Using two-dimensional cylindrically-symmetric physical and mathematical model and an algorithm, a numerical investigation of the problem of irradiating a volumetric aluminum target with a single femtosecond laser pulse is carried out. The problem has a number of fundamental and practical applications related to the hardening effect of residual plastic deformations after the passage of a laser-induced shock wave, in particular, laser shock hardening technology, also known in the literature as laser forging, laser riveting or laser peening.
Axial symmetry of laser beam makes it possible to reduce the dimension of the problem from three-dimensional to two-dimensional and significantly save computational resources. Semi-empirical equation of the state of aluminum in the form of a Mi—Gruneisen with the adjustment of parameters according to the cold curve of the metal and the data of shock-wave experiments was used.
The law of shock wave propagation and attenuation is investigated, the stages of (1) single, (2) transient and (3) hemispherical shock wave propagation are identified. The size and shape of the area on which the strengthening effect can be carried out by a single femtosecond laser pulse are described.
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