An Erratum to this paper has been published: https://doi.org/10.1134/S0018151X23010224

Селективное лазерное сплавление (СЛС) является перспективным направлением аддитивных технологий. Проблема контроля микроструктуры и качества конечного изделия, получаемая методом СЛС, решается подбором режимов плавления с помощью экспериментального поиска или численного моделирования. На сегодняшний день сформировалась многоуровневая методология моделирования СЛС-процессов, которая и рассматривается в настоящей работе.

At present, an intense development occurs in investigations of metamaterials having unique properties that depend on their micro- and nanogeometry. Additive technologies, especially in selective laser melting, open ample opportunities for creating such metallic metamaterials. The presented investigation deals with processes of heat transfer of metamaterials with gyroid-type microgeometry.

This article is devoted to the simulation of the processes of formation of dust clouds in the absence of gravitation, which is necessary for understanding the processes proceeding in dust clusters in outer space, upper planetary atmosphere, and on the surface of space objects, as well as for evaluating the possibilities of creating disperse structures with given properties. The chief aim of the simulation is to determine the general laws of the dynamics of the dust cloud at the initial stage of its formation. With the use of the original approach based on the particle-in-cell method that permits investigating the mechanics of large ensembles of particles on contemporary computational platforms, we consider the mechanics of a dusty medium in the process of its excitation in a closed container due to the vibration of the walls, and then in the process of particle scattering when the container opens in outer space. The main formation mechanisms of a dust formation have been elucidated, and the possibilities of mathematical simulation for predicting spatial and time characteristics of disperse structures have been shown.

The statistical properties of dense random packings of ellipsoidal bodies in cylindrical vessels created under the effect of the gravity force are investigated by the numerical method developed from the equations of mechanics of a rigid body. The body-to-body and body-to-wall interaction is described by elastic forces. It has been found that the influence of the gravity force in the presence of walls specifies the statistically meaningful anisotropy of the orientation of ellipsoids. According to the method of the formation of a packing and the spatial separation of bodies by size can be found; this causes a local narrowing of the size spectrum. The method is naturally generalized by including friction forces, arbitrary force fields, and walls of an arbitrary shape.

Thermophysical processes occurring during the thermal decarbonization of natural carbonate minerals (limestones, magnesites) have been investigated. A new model of the working process of burning a single spherical carbonate granule in the form of a system of ordinary differential equations has been proposed. This system makes it possible to generalize, in a natural manner, the model to the multidimensional and nonstationary cases where a moving mass of loose material is described. A comparison of the numerical calculations of the decarbonization dynamics and the measurement results obtained under totally controlled laboratory conditions has proved the high accuracy of the proposed model.