National University of Science and Technology Moscow Institute of Steel and Alloys, Moscow, Russia

E. A. Naumova, Associate Professor of the Metal Forming Department, Candidate of Technical Sciences, e-mail: jan73@mail.ru
M. A. Vasina, Project Engineer of the Metal Forming Department, Candidate of Technical Sciences
S. A. Finogeev, Postgraduate Student of the Metal Forming Department
A. O. Bobrysheva, Postgraduate Student of the Metal Forming Department

Thermodynamic calculations (using Thermo-Calc (TСAL4 database) software) and experimental methods were applied to study formerly not investigated phase diagrams Al – Cе – Zn and Al – Ca – Cе – Zn in the area of aluminum angle, including construction of liquidus curves and polythermal cross-sections. We studied 6 Al – Cе – Zn alloys and 6 Al – Ca – Cе – Zn alloys. Melting was conducted in a resistance furnace by Graficarbo (Italy). The microstructure of the cast and heat treated samples was studied with an optical microscope (OM), Olympus GX51 (Japan), and a scanning electron microscope (SEM) TESCAN VEGA 3 (the Czech Republic). It has been determined that in Al – Cе – Zn in primary crystals of the phase, Al11Ce3 is dissolved to 8.91% (wt.) (to 7.19% (at.)) Zn, forming the (Al, Zn)₁₁Ce₃ compound, and zinc atoms replace aluminum atoms. At a cooling rate of 20 K/s a boundary of phase zones is shifted, expanding a zone of an aluminum solid solution. In Al – Ca – Cе – Zn in primary crystals of the phase, Al4Ca is dissolved to both zinc and cerium. But zinc is dissolved approximately twice as much than cerium (7.0% (wt.) Zn and 3.74% (wt.) Ce), forming the (Al, Zn)₄(Ca,Ce) compound, where zinc replaces aluminum, and cerium replaces calcium. With an increase in the amount of zinc in the Al – Ca – Cе – Zn alloys, an aluminum solid solution zone is narrowed. We studied hypo-eutectic alloy Al – 4 Ca – 3 Ce – 4 Zn. Its microstructure consists of dendrites of an aluminum solid solution and highly-dispersive eutectics. Zinc was distributed between a solid solution and eutectics at a ratio of about 1:1. The cast samples were rolled with a total reduction of over 80%. Hot rolling was carried out on laboratory mill 260 (Russia). The samples were tested for tensile strength on Zwick/Roell Z250 (Germany), a universal testing machine. Mechanical properties of the rolled products: ultimate tensile strength is 180 MPa, yield strength is 107 MPa, and percentage elongation is 10%. This composition may be deemed to be a promising high-technology “natural composite”.
The research was funded by the Russian Science Foundation, grant No. 20-19-00746-П.

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