Investigation of the Properties of Heat-Protective Coatings to Improve the Performance of Products

Abstract

The heat-loaded part of the combustion chamber of a liquid rocket engine are Considered. The proposed coating has several layers: an internal metal coating that contacts the part or substrate, and an external coating made of a mixture of ceramic granules and metal powder. At the same time, to obtain the initial surface for coating with the required surface layer roughness, it is proposed to use the method of sand blasting. The article analyzes possible mechanisms of material formation for "base-coating" transition zones, as well as the influence of their chemical composition on the adhesive strength of layers.. The choice of brand and combination of materials used for coating is justified. Technological modes that have been tested in production conditions when applying heat-resistant coatings to parts of modern rocket engines are proposed. The influence of technological parameters of the initial surface preparation process and the geometry of the resulting micro-relief of the substrate on the adhesion characteristics of a multilayer coating made of heat-protective materials operating in the high-temperature zone of the combustion chamber of liquid rocket engines is revealed.

Coating roughness impact on the combustion chambers life of the turbo engines

“…Plasma flame spraying is generally used to apply the ceramic and base coat layers because it has proved to provide durable and reproducible coatings. The studies on the coating material and on its application are still being performed, [14][15][16][17][18][19][20] but besides the thermo-mechanical properties of the TBC, its surface roughness may also affect the performance of the coating, especially the life of the liner and so the combustion chamber of the turbo engine. Predicting component life is an essential part of reliability and service warranties and several efforts have been made in this area.…”