| Abstract: | The article is a continuation of the publication cycle of the authors the on the theme “Multifunctional Protective Coatings for Especially Thermally Loaded Elements of Constructions of Hypersonic Systems.” Modern domestic approaches to the formation of single-layer and multilayered high-temperature protective coatings of various classes such as glass–ceramics ones obtained by various methods, coatings based on oxide ceramics, oxygen-free reaction-coupled coatings, and microcomposition coatings of the synergetic type are analyzed. Attention is paid to the fact that the scientific-and-applied investigation directed at the development of the structural and physicochemical models of the coating architecture and substantiation of their functioning with high-speed gas streams are almost absent. The selection of the chemical composition of coatings and production procedures of their formation is performed mainly based on the empirical basis. A series of coatings claimed as workable in conditions in a medium of tranquil or weakly perturbed air up to temperatures of 1600–2000°C is presented; however, their protective ability in conditions of the effect of high-enthalpy supersonic and hypersonic gas streams cannot be judged because of the insufficiency or absence of required data. Microcompositional coatings of the synergetic type based on the Si–TiSi2–MoSi2–B–Y system, which were developed in terms of an original conceptual approach to the formation of a multilevel system of heat protection of thermally stressed constructional elements made of heat-resistant materials of hypersonic aircrafts and their propulsion systems, are especially emphasized. A detailed analysis of their functioning in the composition of a unique construction wall with protected carbonaceous materials will make it possible to determine the tendencies and directions of subsequent investigations by the authors with the purpose of improving the developments. |
