ПІДВИЩЕННЯ СТРУКТУРНОЇ СТАБІЛЬНОСТІ ТА ВЛАСТИВОСТЕЙ ЖАРОМІЦНИХ НІКЕЛЕВИХ СПЛАВІВ ДЛЯ ЛОПАТОК ГТД ОБРОБКОЮ НАНОМАТЕРІАЛАМИ

An analytical review of existing views on the problem of increasing the heat resistance, heat resistance, and durability of high-temperature nickel alloys of the ZhC3 group of blades of gas turbine engines is carried out. The effect of alloying elements of alloys on structural transformations, types of hardening and corrosion resistance is analyzed. A complex powder modifier based on titanium carbonitride Ti (CN) is proposed for processing nickel melts. The choice of nanodispersed Ti (CN) carbonitride powders of a fraction of less than 100 nm as modifiers of low-alloy steels is substantiated. It has been established that Ti (CN) titanium carbonitride particles have a face-centered crystal lattice. The necessary criteria for the selection of nanopowder modifiers have been obtained: insolubility in the melt, correspondence of crystal lattices with the matrix of steel, proportionality with the critical radius of the austenite embryo during crystallization. A mechanism for the interaction of a steel melt with a layer of a nanodisperse composition is established. The macro- and microstructure of nickel alloys ZhC3, ZhC3DK was investigated. An analysis of microdiffraction patterns of particles is carried out, the nanopowders are shown to belong to solid crystalline bodies with a metallic bond. The coarse-grained and low-plastic matrix of the nickel alloy is under the influence of a large local loading, which contributes to the premature cracking of grain boundaries. Modification leads to significant changes in the structure of the alloy ZhC3 in comparison with the unmodified state. The structure of ZhC3 after modification is homogeneous, fine-grained. In modified samples, the grinding of grain was achieved 3 ... 5 times and the structure was stabilized in comparison with the initial state. Mechanical studies of samples in a modified state showed an increase in all parameters: tensile strength by 10 %; yield strength - by 13 %; the elongation by 20 % and the impact strength by 40 % compared to the original samples. Tests of samples for heat resistance showed a decrease in the depth of corrosion at a temperature of 1000 °C in the modified state on average by 25 %, which confirms the effect of modifying the alloys with nanodispersed modifiers.