Моделирование управляемого синтеза интерметаллидного композита с разными способами описания кинетики фазообразования

Abstract

Currently, multilevel (multilevel), multiscale (multiscale) and multiphysical (multi-physical) approaches to modeling the synthesis of new materials are of great interest. The purpose of this work is to compare two modeling approaches to the synthesis of coatings from Ti and Al powders on a substrate under the condition that the process is controlled by a moving heat source. The first approach consists in a formal description of the reactions sequence based on formal kinetics. The result is the composite coating composition depending on the parameters of the movable heat source. The second way of describing phase formation leads to a two-level model, in which the separation by description levels is associated with the separation of physical processes. The macrolevel problem includes the thermal part. The problem at the meso level gives the phase composition at each point of the macrosample and is solved in the quasi-stationary approximation. Based on the solution of the problem in each reaction cell, the distribution of aluminum and titanium concentrations, the phase boundaries position and the volume fractions of all phases in the cells at an arbitrary point in time, corresponding to the volume fractions of the phases at each point of the macrosample, are found. The resulting volume fractions of the phases are converted into mass concentrations of intermetallic compounds for comparison with the model of the first type. It is shown that both approaches lead to close values of the average integral concentrations of the phases. However, the dynamics of phase formation can differ significantly.