Hydrodynamic Modeling of Laser-Induced Shock Waves in Aluminum in a Cylindrically Symmetric Statement

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. The axial symmetry of laser beam permits one to reduce the dimension of the problem from three to two and save considerable computational resources. Semiempirical equation of state of aluminum in the Mie–Grüneisen form is used with the adjustment of parameters according to the cold curve of the metal and the data of shock-wave experiments. The law of shock wave propagation and attenuation is investigated, and 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.