Improvement of friction units of power plants by aplying ceramic composite spray coatings

Abstract

Modifying the working surface of a product by applying protective and functional coatings makes possible considerable changes in the mechanical, optical, electrical, magnetic, thermal and chemical properties of the original structural material, its real surface, producing articles with protective, for example, anti-corrosion, wear-resistant and other properties. We investigated the possibility of improving the friction units of aircraft power plants by applying nanostructured ceramic composite spray coatings. A heavily loaded bearing forming a part of the gearbox of a turbojet engine is used as a prototype of the friction unit. The advantages and drawbacks of improved friction units as compared to production models and their prototypes made according to an improved technology are assessed. The results obtained during the experimental work are presented. A positive conclusion is made about the use of nanostructured composite materials in the development of friction units; the most favorable method of coating is determined.

Providing of Operational Properties for Gas-Turbine Engine Parts and Assemblies Using Electrospark Deposition

“…In the coatings, a softening of the bonds of carbon atoms, the addition of hydrogen and oxygen atoms to carbon atoms with free valences (intensity ratio ID/IG = 1.57) was detected. Obviously, the formation of such a composition is associated with the peculiarities of the processes of electrical discharge action and transfer of the electrode material to the titanium substrate [18], [19]. Due to the intensive processes of dispersion and sublimation of the anode -graphite already at the beginning of the ESA process, a layer of fine graphite appears on the cathode, in the zone of impact of the discharges, which, during further processing, covers the entire surface being doped.…”