¹National University of Science and Technology “MISiS”, Moscow, Russia ; ²Moscow State Technological University “STANKIN”, Moscow, Russia:

E. A. Naumova, Associate Professor^{1, 2}, Metal Forming Department, e-mail: jan73@mail.ru

National University of Science and Technology “MISiS”, Moscow, Russia:
M. I. Petrzhik, Professor, Powder Metallurgy and Functional Coatings Department
P. K. Shurkin, Post-Graduate Student, Metal Forming Department
A. A. Sokorev, Senior Lecturer, Department of Foundry and Artistic Processing of Materials

In an effort to optimize the composition of high-strength Ca-containing aluminum alloys, the dependences of the hardness of Al – 2.5Mg – (0...10)Ca – (0...14)Zn (wt.%) compositions upon the aging temperature have been studied. The structure of alloys and the composition of individual microstructure constituents have been investigated by means of light and scanning electron microscopy as well as the energy dispersive X-ray microanalysis (EDXMA) method. Determined are the concentrations of Zn in primary crystals and in a eutectic for all experimental alloys. It was fixed that the composition of primary crystals in Al – 2.5Mg – 4Ca – 12Zn, Al – 2.5Mg – 6Ca – 12Zn and Al – 2.5Mg – 10Ca – 14Zn alloys accords with the Al₃ZnCa phase. The hardness and elastic modulus of (Al,Zn)₄Ca primary crystals and [(Al) + (Al, Zn)₄Ca] eutectic in Al – 2.5Mg – 10Ca – (1…14)Zn alloys have been determined by the instrumented nanoindentation method. It was found that these mechanical properties are rising as the concentration of Zn in primary crystals increases. According to the study fulfilled, the best combination of mechanical and technological properties has been achieved in Al – 2.5%Mg alloys with the content of Ca varied from 3 to 4% and Zn from 8 to 10%.

This work was supported by Task No. 11.2072.2017/4.6 for the implementation of the project on the theme of “Development of technology for obtaining deformed semi-finished products from alumomatrix eutectic composites reinforced with L12 nanoparticles without hardening”.

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