Особенности инициирования подвижным источником энергии реакций в плоском слое, расположенном на подложке

Abstract

In the conditions of the surface treatment of materials and coating application using mixtures of powders (metals, metals and nonmetals, metals and oxides) capable of chemical interactions, problems similar to those of solid-phase combustion theory arise. Currently available publications, which confirm the fact of the reactions, are limited to the analysis of the obtained structures, mechanical properties and the statement of the presence of certain compounds and phases. We present the reduced models for the synthesis of composites on a planar substrate allowing us to analyze qualitative effects. The first model is one-dimensional with a total reaction. The second model corresponds to the synthesis of a matrix-inclusion-type composite. The process is assumed to be driven by a moving heat source. Both models take into account the properties of the substrate. The transition to dimensionless variables reveals both the parameters characteristic of macrokinetics and the parameters typical for modern material synthesis technologies. The numerical solution shows that in the presence of a mobile heat source the reaction zone is sufficiently wide, and the temperature dynamics in general is dissimilar to that of combustion processes. It is shown that there is a parameter region in which partial transformation is observed. Two characteristics of the synthesis process have been determined - the time of the reaction initiation and the time of half-transformation (for a sample of finite size). Taking into account detailed kinetics, similar studies allow us to predict the qualitative composition of synthesis products when changing the conditions and initial composition of powder mixtures.