УТВОРЕННЯ НЕМЕТАЛЕВИХ ВКРАПЛЕНЬ ПРИ ТВЕРДНЕННІ ЖАРОМІЦНИХ СПЛАВІВ ТА ПРИЙОМИ РАФІНУВАННЯ РОЗПЛАВІВ: Processy litʹâ, 2021, Tom 145, №3, p.12-23

• Date: 2021
• Main Authors: Шинський, О. Й., Квасницька, Ю. Г., Максюта, І. І., Михнян, О. В.
• Format: Article
• Language: Ukrainian
• Published: National Academy of Sciences of Ukraine, Physical-Technological Institute of Metals and Alloys of NAS of Ukraine 2021
• Subjects: жароміцні нікелеві сплави; мікролегування; внутрішньоформене фільтрування; рафінування; пінокерамічний фільтр; неметалеві вкраплення
• Online Access: https://plit-periodical.org.ua/index.php/plit/article/view/68
• Journal Title: Casting Processes

Received 03,08.2021 UDK 669.245:513.71 Minimization of melt contamination of heat-resistant alloys from the excess content of harmful impurities, non-metallic inclusions during crystallization in the production of parts of gas turbine engines provides the authors microanalloy alloys with lanthanum for followed by the use of refining ISSN 0235-5884. Процеси лиття. 2021. № 3 (145) 23 Взаємодія фаз effective ceramic filters in-mold filtration of melts, the composition of which was developed with the participation of the authors and tested in the enterprise. The choice of temperature indicators of the limiting intervals of the filtration process was carried out in accordance with the temperatures of the main phase transformations (TS , TL), which were detected by the method of differential scanning calorimetry. Metallographic, electron microscopic, X-ray diffraction and MRSA methods have shown that sulfur, which is a powerful surfactant in the form of refractory compounds of lanthanum sulfides formed by microalloying, concentrates on the walls of the crucible at the interface between the alloyceramics during melting and by adhesion on the surface of the filters during refining during filtration. As a result, there is a sharp decrease in the content of sulfides in the alloy, instead of low-melting inclusions of nickel sulfides in the alloy remains a small amount of refractory lanthanum sulfide. It was found that since the NiP compound has a low melting point (850 0C), the phases containing phosphorus are the site of stress and crack propagation, which is associated with their location mainly at the grain boundaries, the formation of β-NiAl and phosphide niobium. Phosphorus is a weak surfactant, resulting in reduced refining efficiency compared to sulfur. It is empirically shown that due to partial purification of grain boundaries from inclusions of sulfides, oxides, phosphides, there is a decrease in grain size, grinding of eutectic secretions of γ - γ΄-phases. The number of non-metallic inclusions, their total volume content, %, decreased by 1.3-1.5 times. A comparative analysis of the mechanical properties of alloys after different methods of refining castings shows that the metal, which is additionally microalloyed by lanthanides, in this case lanthanum, followed by in-mold filtration, has an increase in mechanical properties at room temperature and at elevated temperatures. The use of the composition of more chemically and thermally stable refractory foundry ceramics (crucibles, molds, rods, filters) developed with the participation of the authors also significantly prevents contamination of the melt during crystallization by excess impurity elements.