Effect of Phase Composition and Internal Structure Parameters on the Functional Properties of High–Temperature Heat–Protective Ceramic Composites MgO–MgAl2O4

The paper presents the results of a study of the functional properties of high–temperature heat–protective ceramic materials based on a composition of MgO and MgAl2O4 in a wide range of component concentrations. It is shown that a decrease in the characteristic size of powder particles by two orders of magnitude and an increase in the quality of adhesion provide the achievement of extremely low thermal conductivity of sintered ceramics in combination with high strength and fracture toughness. By varying the volume fraction of components, it is possible to purposefully shift the balance of thermal conductivity, resistance to thermal shocks, and mechanical properties of heat–protective products in relation to specific operating conditions. Quantitative estimates of the effect of micro- and submicroscale discontinuities of the internal structure on the macroscopic functional characteristics of ceramic composites were obtained using computer modeling.