Academic Journal

Low-temperature superplastic deformation of the EK79 nickel-based superalloy with the mixed ultrafine-grained microstructure

التفاصيل البيبلوغرافية
العنوان: Low-temperature superplastic deformation of the EK79 nickel-based superalloy with the mixed ultrafine-grained microstructure
المؤلفون: Elvina V. Galieva, Ekaterina Yu. Klassman, Vener A. Valitov
المصدر: Frontier Materials & Technologies, Iss 1, Pp 19-27 (2024)
بيانات النشر: Togliatti State University, 2024.
سنة النشر: 2024
المجموعة: LCC:Materials of engineering and construction. Mechanics of materials
مصطلحات موضوعية: heat-resistant nickel-based superalloy, ek79, strengthening phase, microduplex microstructure, ultrafine-grained microstructure, low-temperature superplasticity, thermomechanical treatment, uniaxial compression, Materials of engineering and construction. Mechanics of materials, TA401-492
الوصف: One of the most effective ways to increase the processing plasticity of advanced superalloys (heat-resistant nickel-based alloys) is the formation of an ultrafine-grained (UFG) microstructure in bulk semi-finished products. Such a microstructure is a necessary condition for the manifestation of the structural superplasticity effect in the technological processes of manufacturing products from such superalloys. One of the most promising methods for producing UFG microstructures is thermomechanical treatment (TMT) according to the multiple isothermal forging scheme. It has been shown that the EK79 superalloy after TMT, with a gradual decrease in the processing temperature from 0.88 to 0.62 Ts (where Ts is the strengthening phase dissolution temperature) leads to the transformation of the initial microduplex fine-grained microstructure into a mixed UFG microstructure. Such a mixed UFG microstructure consists of: 1) relatively coarse (inherited from the fine-grain microstructure) particles – γ'-phase with a size of 3.0±0.8 μm; 2) γ-grains, and incoherent γ'-phase particles with a size of 0.3–0.5 μm; 3) strengthening coherent intragranular γ'-phase particles with a size of 0.05–0.1 μm, released upon cooling from the TMT temperature to room temperature. During uniaxial compression tests, the EK79 superalloy with such microstructure, demonstrates low-temperature superplasticity in the temperature range of 800–1000 °C. It has been found that an increase in the deformation temperature up to 1000 °C, leads to the increase of γ-phase grains to micron size. The maintenance of superplastic properties in the presence of relatively coarse incoherent particles in the microstructure of the second phase (γ'-phase) is apparently related to the fact that the deformation is localised in the UFG component.
نوع الوثيقة: article
وصف الملف: electronic resource
اللغة: English
Russian
تدمد: 2782-4039
2782-6074
Relation: https://vektornaukitech.ru/jour/article/view/904/859; https://doaj.org/toc/2782-4039; https://doaj.org/toc/2782-6074
DOI: 10.18323/2782-4039-2024-1-67-2
URL الوصول: https://doaj.org/article/9c99e37312554d0b9177936790933862
رقم الانضمام: edsdoj.9c99e37312554d0b9177936790933862
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