Study of the Effect of Laser Ablation on the Structure of a BCC Crystal Using Molecular Dynamics Simulation

Abstract

An external high-energy impact on the surface of a solid, for example, by ultrashort ultra-high-power laser pulses, can lead to phase transitions, as a result of which the surface structure undergoes cardinal changes. This paper presents the results of molecular dynamics modeling of changes in the surface layer of the computational cell under a short-term high-energy impact. The model constructed and described in the paper, in which the temperature of the computational cell is distributed in accordance with the solution of the linear problem of heat conduction, made it possible to reveal a violation of the continuity of the surface layer, which consists in the localization of excess free volume in the form of a group of spherical pores. The sizes of these imperfections, as well as the duration of their existence, have differences when modeling different energy densities of laser radiation. Further research made it possible to reveal the conditions under which the pores remain stable throughout the entire simulation time, as well as to reveal the relationship between the crystallographic orientation of the "solid — liquid" interface and the sizes of the formed pores.