Ремонт деталей авіаційних двигунів із жароміцних нікелевих сплавів із застосуванням адитивних плазмових технологій

In order to improve the maintainability of aircraft engine parts, the article examined the use of additive technologies in repairs. The article establishes that the use of additive technologies by the method of plasma surfacing in the repair of aircraft engine parts, such as turbine blades, sealing discs, NA parts, is very promising and will significantly increase the percentage of parts and assemblies restored after operation, which have a significant area of damage. Turbine blades are made of nickel heat-resistant alloys with a polycrystalline structure (ЖС6К-ВИ, ЖС6У-ВИ), or from alloys with directional crystallization (ЖС32-ВИ, ЖС26-ВИ). After operating for more than 6 thousand hours, in addition to the operational wear of the ends and side walls of the shroud flanges, thermal fatigue cracks up to 6 mm deep are observed on the blades received for repair. The technology of argon-arc surfacing and the surfacing materials existing for this process do not provide the heat-resistant properties of the restored surface necessary for the operation of the blades. The solution to the problem was achieved through the use of a compressed arc source with precision adjustment of the welding current and mechanization of the supply of filler material (powder), which would make it possible to surfacing with a limited penetration depth and, accordingly, mixing the deposited material with the base metal. The developed technology made it possible to restore damaged sections of blades after operation (shroud flanges, labyrinth scallops, z-shaped profiles and airfoil ends) on heat-resistant alloys using filler material equal to the strength of the base metal. For this process, powders of nickel and cobalt alloys with a fraction of +63...-160 microns are used, obtained by atomization with a jet of inert gas (argon). The main powders used are ЖС32-ВИ, ЖС6К-ВИ, В3К, Stellite 12, Stellite 6, ХТН61. Disc material – ЭП742-ИД. Working medium, air, oil and combustion products. The maximum heating temperature of labyrinth scallops is up to 680 ºC at a maximum medium pressure of up to 1.47 MPa. The maximum peripheral speed of the scallop end is 251 m/s. Material of seal mating parts ЭИ435 (cell δ = 0,1 mm). When developing the technology, the successful experience of restoring labyrinthine scallops of turbine blades was taken into account. The restoration of the labyrinthine ridges of the disk was carried out using a compressed arc source with precision control of the welding current