Bauman Moscow State Technical University, Moscow, Russia:

O. P. Matveeva, Professor of a Chair “Rocket Launching Systems”, e-mail: sm8@sm8.bmstu.ru

JSC “Giredmet”, Moscow, Russia:
Yu. B. Patrikeev, Head of Laboratory of Technology of Obtaining of Rare-Earth Metals, Powders and Alloys, e-mail: ybpatrikeev@giredmet.ru
Yu. M. Filyand, Senior Researcher of Laboratory of Technology of Obtaining of Rare-Earth Metals, Powders and Alloys, e-mail: jmfilyand@yandex.ru

Our study shows the methodical approaches to substantiation of technological parameters for hydrogen storage alloys production in arc furnaces with permanent electrodes. They allow to determine a correlation between the conditions of heat exchange during ingot solidification, the crystal structure and hydrogen capacity of the alloys and their manufacturing costs. The influence of material macrostructure on the amount of absorbed hydrogen and the dependence of this value from heat transfer processes during solidification were experimentally studied. The high intensity of heat exchange processes between the alloy and the water-cooled ingot mold helps to reduce grain size and, as a consequence, to increase hydrogen capacity. Heat exchange processes between the crystallizing ingot and the water-cooled ingot mold were analyzed taking into account an average temperature and variation of the flow regimes of the coolant. Quantitative limitations for the ingot mass were defined, depending on the weight and size of the mold in which the ingot is formed. Systematic approaches allowing to improve the technology of hydrogen storage alloys production were developed on the basis of obtained results. For this purpose, the direct and inverse optimization problems were formulated. Their solution will aid to produce materials having hydrogen capacity specified by consumer, and to minimize the manufacturing cost. The offered approaches were used in the development of production technology of intermetallic compounds Mm_1–yLayNi₄Co that exhibit increased hydrogen capacity, low hysteresis, mild activation conditions and optimal technological and operational characteristics. Such properties allow to apply these alloys for hydrogen storage and purification, and also for energy conversion in metal hydride heat pumps.

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