Microstructure and properties of the eutectic 12Si–Al alloy subjected to barothermal treatment
- Авторы: Dedyaeva E.1, Nikiforov P.2, Padalko A.1, Talanova G.1, Shvorneva L.1
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Учреждения:
- Baikov Institute of Metallurgy and Materials Science
- Ufa Motor Works
- Выпуск: Том 2016, № 9 (2016)
- Страницы: 856-863
- Раздел: Article
- URL: https://journals.rcsi.science/0036-0295/article/view/170868
- DOI: https://doi.org/10.1134/S003602951609007X
- ID: 170868
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Аннотация
A binary 12Si–Al alloy is subjected to barothermal treatment (hot isostatic pressing) at a temperature of 560°C and a pressure of 100 MPa for 3 h. This treatment is shown to result in a high degree of homogenization in the chemically and structurally heterogeneous initial alloy. As follows from the morphology of silicon microparticles, barothermal treatment of the 12Si–Al alloy leads to thermodynamically promoted silicon dissolution in the aluminum matrix up to ~10 at % with the formation of a metastable supersaturated solid solution, which decomposes upon cooling. The process of removal of porosity, which results in the formation of a high-density homogeneous material, is analyzed. After a cycle of barothermal treatment, a bimodal size distribution of the silicon phase constituent forms in the 12Si–Al alloy at an average microparticle size of 2.7 μm and an average nanoparticle size of 36 nm. The linear thermal expansion coefficient of the alloy decreases after barothermal treatment, and the microhardness of the eutectic alloy is determined after this treatment. Barothermal treatment of the 12Si–Al alloy is shown to be an effective tool for the removal of microporosity, achieving a high degree of homogenization, and forming a near-optimum bimodal size distribution of the silicon structural constituent, which is comparable with or even exceeds the results of conventional heat treatment of the material at atmospheric or lower pressure.
Об авторах
E. Dedyaeva
Baikov Institute of Metallurgy and Materials Science
Email: padalko@inbox.ru
Россия, Leninskii pr. 49, Moscow, 119991
P. Nikiforov
Ufa Motor Works
Email: padalko@inbox.ru
Россия, Ufa, Bashkortostan, 450039
A. Padalko
Baikov Institute of Metallurgy and Materials Science
Автор, ответственный за переписку.
Email: padalko@inbox.ru
Россия, Leninskii pr. 49, Moscow, 119991
G. Talanova
Baikov Institute of Metallurgy and Materials Science
Email: padalko@inbox.ru
Россия, Leninskii pr. 49, Moscow, 119991
L. Shvorneva
Baikov Institute of Metallurgy and Materials Science
Email: padalko@inbox.ru
Россия, Leninskii pr. 49, Moscow, 119991