National University of Science and Technology “MISiS”, Moscow, Russia:

K. Yu. Chervyakova, Engineer of the “Casting Technologies and Materials” Engineering Center, Undergraduate of the Casting Process Technology Department
M. E. Samoshina, Senior Researcher of the “Casting Technologies and Materials” Engineering Center, Assistant Professor of the Casting Process Technology Department
N. A. Belov, Deputy Director of the “Casting Technologies and Materials” Engineering Center, Professor of the Casting Process Technology Department, e-mail: nikolay-belov@yandex.ru

Problem of substantiating the aluminum matrix composition for obtaining the heat treatable boron-aluminum alloys in the form of ingots and sheet products. Aluminum-based materials alloyed by boron are promising radiation-resistant structural materials. Analysis of basic systems of the heat treatable (T6) aluminum alloys was carried out. Zinc-containing systems (Al – Zn – Mg and Al – Zn – Mg – Cu) has been excluded because of likelihood of burning-out at high smelting temperatures. With the use of the calculations (Thermo-Calc software) and experimental methods (including scanning electron microscopy and micropobe analysis), justified has been an unreasonableness of obtaining the boron-aluminum alloys based on magnesium-containing systems because of an active interaction of that element with boron. An (Al, Mg)B₂ compound with particles of adverse needle-shaped form arises even at small magnesium concentrations. Experimental study has been focused on the boron-aluminum alloys based on Al – Zr – Sc (with magnesium, manganese and titanium additives) and Al – Cu systems. Alloys have been prepared on the base of high-purity aluminum in a graphite-fireclay crucible at the temperature of 900–950 оС in a RIELTEK («РЭЛТЕК») induction furnace, which provides an intensive melt mixing required to exclude a possibility of refractory boron-containing particles deposition. The melt was poured into a graphite moulds to obtain flat ingots of 40×120×200 mm in size. Samples for structural investigations has been cut thereof. Later on the ingots have been treated by strain and thermal processing. It was found that titanium introduction into the systems with zirconium and scandium doesn’t assist in preventing their interaction with boron, which hamper the aluminum matrix hardening. The Al – Cu system meets the requirements best of all since copper doesn’t interact with boron and doesn’t effect on composition of the boron-containing phases. It was determined that such system allows to obtain ingots and sheet products of aluminum boron-containing alloy possessing high mechanical properties. The maximum achievable hardness on ingots and sheet products amounts to 129 HV and 133 HV correspondingly, and the tensile strength (sheets) equals to 430 MPa.

This article was written within the implementation of the Agreement on subsidies No. 14.578.21.0004 (Unique identifierof the project RMEF157814X0004) between the National University of Science and Technology “MISiS” and the Ministry of Education and Science of the Russian Federation within the framework of realization of the Federal Target Program “Research and Development in the Priority Directions of Progress of the Scientific and Technological Complex of Russia for 2014–2020”, approved by the Decree of the Government of the Russian Federation of November 28, 2013, No. 1096.

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