A Molecular Dynamics Model for Studying the Influence of High Temperatures under Laser Irradiation on Changes in a BCC Crystal Structure

Abstract

The paper discusses the changes in the structures of BCC crystals subjected to high-temperature exposure. The interest in the study is explained by the processes occurring in the liquid surface layer and their subsequent impact on layer crystallization. They will further affect various physical and geometric characteristics of the material surface as a whole. The presented model helps observe the imperfections of the structure caused by the appearance of pores on the surface layers of the metal. The computational cell temperature in the designed model is distributed according to the solution of the linear problem of heat conduction. The model allows for revealing a surface layer continuity violation when the excess free volume localizes in the form of a group of spherical pores. The dimensions of such imperfections, as well as the duration of their existence, differ when modeling different laser radiation energy densities. Further research reveals the conditions for the pores to remain stable throughout the entire simulation time, as well as the relationship between the crystallographic orientation of the “solid-liquid” interphase boundary and the sizes of the formed pores” interphase boundary and the sizes of the pores formed. Keywords: bcc crystal, molecular dynamics model, interface boundary, porosity.