Сибирский федеральный университет

Тип публикации: статья из журнала

Год издания: 2020

Идентификатор DOI: 10.3390/met10121673

Ключевые слова: al-mg-si-la system, cast aluminum alloy, eutectic modification, intermetallics, lanthanum, mg2si, microstructure, rare earths, solidification

Аннотация: The current study focusses on the phase composition, solidification path, and microstructure evaluation of gravity cast Al-4Mg-0.5Si-xLa aluminum alloy, where x = 0, 0.1, 0.25, 0.5, 0.75, and 1 wt.% La. A computational CalPhaD approach implemented in Thermo-Calc software and scanning electron microscopy technique equipped with electron microprobe analysis (EMPA) was employed to assess its above-mentioned characteristics. The thermodynamic analysis showed that the equilibrium solidification path of La-containing Al-Mg-Si alloys consists of only binary phases LaSi2 and Mg2Si precipitation along with α-Al from the liquid and further solid-state transformation of this mixture into α-Al + Al11La3 + Mg2Si + Al3Mg2 composition. Scheil–Gulliver simulation showed a similar solidification pathway but was accompanied by an increase in the solidification range (from ~55◦C to 210◦C). Furthermore, microstructural observations were congruent with the calculated fraction of phases at 560◦C and related to α-Al + LaSi2 + Mg2Si three-phase region in terms of formation of La-rich phase having both eliminating effect on the eutectic Mg2Si phase. Quantitative EMPA analysis and elemental mapping revealed that the La-rich phase included Al, La, and Si and may be described as Al2LaSi2 phase. This phase shows a visible modifying effect on the eutectic Mg2Si phase, likely due to absorbing on the liquid/solid interface. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.

Журнал: Metals

Выпуск журнала: Vol. 10, Is. 12

Номера страниц: 1-12

ISSN журнала: 20754701

Издатель: MDPI AG

• Deev V. (School of Mechanical Engineering and Automation, Wuhan Textile University, Wuhan, 430073, China, Department of Metal Forming, National University of Science and Technology MISiS, Moscow, 119049, Russian Federation)
• Prusov E. (Department of Functional and Constructional Materials Technology, Vladimir State University Named after Alexander and Nikolay Stoletovs, Vladimir, 600000, Russian Federation)
• Shurkin P. (Department of Metal Forming, National University of Science and Technology MISiS, Moscow, 119049, Russian Federation)
• Ri E. (Department of Foundry Engineering and Metal Technology, Pacific National University, Khabarovsk, 680042, Russian Federation)
• Smetanyuk S. (Department of Foundry, Siberian State University, Krasnoyarsk, 660041, Russian Federation)
• Chen X. (College of Mechanical and Electrical Engineering, Wenzhou University, Wenzhou, 325035, China, Department of Metals Technology and Aviation Materials, Samara National Research University, Samara, 443086, Russian Federation)
• Konovalov S. (College of Mechanical and Electrical Engineering, Wenzhou University, Wenzhou, 325035, China, Department of Metals Technology and Aviation Materials, Samara National Research University, Samara, 443086, Russian Federation)

• Scopus