COMPOSITION AND STRUCTURE OF POROUS HEAT-RESISTANT INORGANIC COMPOSITE MATERIALS

This paper is a continuation of our series of papers devoted to the production of ceramic and composite nanomaterials based on various inorganic heat-resistant binders. The work is devoted to important aspects that determine the properties of such materials: micro- and macrostructure, and the chemical composition. These factors are of particular importance for the production of porous, heat-resistant materials. In this paper, the main types of porous heat-resistant materials are considered. Porous materials are the solids that contain voids in a sufficiently large amount, and the average size of individual voids is significantly smaller than the body size. The structure of porous materials is characterized by the following parameters: general or true porosity, closed porosity, open or apparent porosity, average pore size and size distribution function, specific pore volume, specific surface area, the degree of the material anisotropy, permeability. It is shown that the method of production of porous materials has a great influence on the formation of the pore structure of materials. By changing the technological parameters of production of porous products, it is possible to regulate both the total porosity and the nature of the structure of the porous material. The analysis and comparison of the concepts that characterize the behavior of materials at high temperatures (refractoriness, thermal resistance, heat resistance, dross resistance, high-temperature strength) have been performed. Various chemicals with the greatest thermal stability and refractoriness have been compared. Various porous heat-resistant inorganic composite materials manufactured by industry have been analyzed. Various chemicals with the greatest thermal stability and refractoriness have been shown. The phase diagrams of such compounds were analyzed. Systems and phase compositions, optimal for creating heat-resistant porous materials, were recommended.