Робота присвячена пошуку нових вакуум-плазмових покриттів з високою твердістю для підвищення довговічності компресорних лопаток ГТД авіаційних двигунів В якості кандидатних обрані вакуум-плазмові покриття на основі Ti-Al-N, отримувані за технологіями Avinit, які забезпечують нанесення твердих якісних покриттів з різко зменшеним пошкодження мікродугами. Багатошарові покриття Avinit мають більш високі, ніж TiN, функціональні характеристики (мікротвердість, тріщиностійкість, температуростійкість, ерозійну та корозійну стійкість) і можуть бути перспективними для нанесення ерозійно-стійких покриттів для компресорних лопаток. Технології Avinit технологічно найбільш близькі до використовуємих у промисловому виробництві вакуум-плазмових технологій нанесення захисних покриттів TiN. Розроблені нові багатошарові 2D-нанокомпозитні зносостійкі іонно-плазмові тверді покриття Avinit (TiN-AlN)n . Створені програмні продукти дозволили вийти на якісно новий рівень щодо подальшого модифікування та вдосконалення конструкцій функціональних покриттів Avinit, стабільності технологій та підвищення контролю їх якості при нанесенні таких покриттів для використання у виробництві компресорних лопаток ГТД авіаційних двигунів. Особливу увагу приділено методам попередньої іонно-плазмової обробки поверхонь перед покриттям. Проведені металографічні дослідження хімічного і фазового складу і структури покриттів Avinit (TiN-AlN)n .Товщина покриттів 7-9 мкм, мікротвердість 34-35 GPa (в порівнянні з серійно використовуємого покриття TiN: 27,4 GPa). Застосування в технологіях Avinit тристадійної іонно-плазмової обробки з використанням подвійного вакуум-дугового розряду з подальшим нанесенням зміцнюючих покриттів в єдиному технологічному циклі, виключає тріщиноутворення і забезпечує отримання міцнозчеплених високоякісних покриттів заданого складу з максимально зменшеною долею крапельної складової. Нанесені розроблені покриття (TiN-AlN)n на дослідні партії робочих компресорних лопаток ГТД авіаційних двигунів для проведення стендових випробувань.
For the first time, an algorithm for measuring the altitude of a helicopter or unmanned aerial vehicle based on the processing of broadband pulsed noise signals is synthesized by the method of maximum likelihood. When formulating the problem, the mathematical model of the signal and observation is specified, their statistical characteristics are investigated. The peculiarity of the synthesis problem is the use of a noise pulse transmitter, which implements the function of illuminating the underlying surface, as well as taking into account the fact of the signal structure destruction during its radiation, propagation and reflection. This destruction of the waveform makes it impossible to synthesize radar with internally coherent processing when working on one receiving antenna. An appropriate structural diagram of the radar is developed and the results of its modeling are presented.
Technology has been developed for repairing the nozzle assembly (SA) casing in the D-18T engine by additively growing the damaged part by microplasma surfacing with a powder of EP648VI (KhN50VMTYUB-VI) alloy. Traditionally, a part with such damage was rejected. The cost of replacing a damaged part with a new one is about 200 thousand hryvnias. The article discusses the equipment and features of the growing technology using the method of microplasma multilayer surfacing. Additive growth of the cut-damaged part was carried out on a STARWELD 190 H robotic installation for microplasma powder surfacing using EP648 VI alloy powders with a 63–163 micron fraction. After growing, heat treatment (aging at 700 ºС, exposure for 16 hours), mechanical processing, and quality control of the grown part were carried out. To create an evidence base to determine the possibility of installing a repaired part on the engine, a set of studies was carried out, which included the determination of the chemical composition of samples grown using a technology similar to repair, metallographic studies, and mechanical tests. As a result, it was found that the chemical composition of the deposited metal meets the requirements of the technical specifications TU 14-1-3046-97 "Bars made of heat-resistant alloy grade KhN50VMTYUB (EP648), and the microstructure of the deposited metal after heat treatment is a γ - solid solution with the presence of carbides, carbonitrides and a small amount of γ´ phase, which corresponds to the normally heat-treated state of the EP 648 VI (KhN50VMTYUB-VI) alloy and the level of mechanical properties of the grown alloy with subsequent serial heat treatment (aging at 700 ° C, holding for 16 hours) not lower than the level of the forging used at serial production of a part. The economic effect of the introduction of this technology is shown, which is more than 100 thousand hryvnias (about 23% of the cost of a new part).
The article considers coatings deposited on turbine blades via plasma vapor deposition (PVD) method with Ni-Cr-Al-Y cathodes obtained using powder metallurgy (PM) and electron beam remelting process (EBMR). The study analyzes the effect of cathodes manufacturing techniques on surface roughness of rotor turbine blades. Task: to examine a microstructure and chemical composition of the considered cathodes; to quantify a droplet phase of a heat-resistant coating of turbine blades subdivided into size-fractions. Methods used optical microscopy, SEM-analysis. Next results were obtained. In the microstructure of two cathodes under study, it is revealed γ-solid solution with intermetallic Ni-Cr-Al and yttrium-based phases. Simultaneously, distribution of the yttrium phase in the PM-cathode more uniform in compare with EBMR-cathode. Metallographic studies showed that yttrium phase in the structure of the PM-cathode is highly-dispersed, with sizes up to 5 microns, and due to structural and dimensional heredity received during cathode hot isostatic pressing compaction. The structure of the cathode obtained using EBMR-process is a series of the conglomerates of intermetallic phases, with more than 50 microns long, which are branched out on volume. The compliance of the chemical composition of the cathodes under study to requirements of the specifications is established. After the coating deposition on turbine blades by a PVD-method with cathodes under study, were not observed any coating delamination, and their thickness corresponded to the specifications. With a distribution analysis of droplet phase on the turbine blade surface were established that coatings with PM-cathode have been characterized by complete absence of a 65 microns droplet phase, and has half less 25…45 microns droplet phase compared with the EBMR-cathode. Conclusions. The coating with PM-cathode has smaller droplet phase on the turbine blade surface and as a result improved their roughness and gas path surface state. The use of PM in the production of the cathodes for protective coatings provides stable performance of installation and provides long-term operation time of cathodes, compared with the EBMR-cathodes.
The article considers coatings deposited on turbine blades via plasma vapor deposition (PVD) method with Ni-Cr-Al-Y cathodes obtained using powder metallurgy (PM) and electron beam remelting process (EBMR). The study analyzes the effect of cathodes manufacturing techniques on surface roughness of rotor turbine blades. Task: to examine a microstructure and chemical composition of the considered cathodes; to quantify a droplet phase of a heat-resistant coating of turbine blades subdivided into size-fractions. Methods used optical microscopy, SEM-analysis. Next results were obtained. In the microstructure of two cathodes under study, it is revealed γ-solid solution with intermetallic Ni-Cr-Al and yttrium-based phases. Simultaneously, distribution of the yttrium phase in the PM-cathode more uniform in compare with EBMR-cathode. Metallographic studies showed that yttrium phase in the structure of the PM-cathode is highly-dispersed, with sizes up to 5 microns, and due to structural and dimensional heredity received during cathode hot isostatic pressing compaction. The structure of the cathode obtained using EBMR-process is a series of the conglomerates of intermetallic phases, with more than 50 microns long, which are branched out on volume. The compliance of the chemical composition of the cathodes under study to requirements of the specifications is established. After the coating deposition on turbine blades by a PVD-method with cathodes under study, were not observed any coating delamination, and their thickness corresponded to the specifications. With a distribution analysis of droplet phase on the turbine blade surface were established that coatings with PM-cathode have been characterized by complete absence of a 65 microns droplet phase, and has half less 25…45 microns droplet phase compared with the EBMR-cathode. Conclusions. The coating with PM-cathode has smaller droplet phase on the turbine blade surface and as a result improved their roughness and gas path surface state. The use of PM in the production of the cathodes for protective coatings provides stable performance of installation and provides long-term operation time of cathodes, compared with the EBMR-cathodes.
