MOLECULAR DYNAMICS SIMULATION OF THE FORMATION OF MISORIENTATION AREAS IN A DEFORMED IRON CRYSTAL UNDER INFLUENCE OF A LASER PULSE

10.25712/ASTU.1811-1416.2024.04.001

Abstract

It is known that the effect of laser pulses on a metal surface is accompanied by processes such as local heating, melting and even evaporation of the metal, which leads to various structural changes in the surface. Obviously, due to the widespread use of lasers as a tool for processing materials, the study of processes accompanying its effects is an urgent task, which, however, cannot always be solved exclusively experimentally and in this case the use of additional research methods is required. In the presented work, the molecular dynamics method is used to study the structural changes occurring in an iron single crystal subjected to relative deformations of various magnitudes under simulated exposure to a laser pulse. It is assumed that such an effect is accompanied only by heating the irradiated material to sufficiently high temperatures. It is shown that as a result of subsequent structural relaxation, dislocations are formed in the crystal, which are a response to external influence, and as the magnitude of the deformation increases, regions of misorientation are formed. Moreover, for misorientation in this case, large deformations are not required, but the presence of a liquid phase, as well as excess free volume, is necessary. It is suggested that the appearance of misorientation regions is also facilitated by tangential stresses created by the interphase boundary.