JSC “Giredmet”, Moscow, Russia:

E. A. Yuzhakova, Junior Researcher of the Laboratory of Technology of Obtaining of Rare, Refractory and High-Pure Metals, e-mail: ElAYuzhakova@giredmet.ru
V. I. Kotlyarov, Head of the Laboratory of Technology of Obtaining of Rare, Refractory and High-Pure Metals, e-mail: VIKotlyarov@giredmet.ru
V. T. Beshkarev, Leading Researcher of the Laboratory of Technology of Obtaining of Rare, Refractory and High-Pure Metals
V. V. Ivanov, Senior Researcher of the Laboratory of Technology of Obtaining of Rare, Refractory and High-Pure Metals

This paper offers the method of production of powders of titanium and titanium-based alloys with the set particle size distribution by hydrogenation and dehydrogenation. The morphology of the received powder changed during plasma spheroidization after which particles acquire spherical shape. Application of the described method allowed to obtain the spherical powder with a countable nodularity of more than 96%. Quality of spherical powders of titanium and titanium-based alloys (obtained by gas atomization method using the thermal energy of plasma) directly depends on the properties of polygonal metal powders treated in plasma stream. Such parameters as chemical composition, content of gas impurity and fractional composition of initial titanium powders are critical. The method of production of polygonal powders of titanium alloys consists of the following stages: receiving ingots with the required structure, their hydrogenation for the purpose of receiving fragile hydrides, crushing and dissipation powders of hydrides, dehydrogenation and classification. The possibility of receiving polygonal powders of titanium alloys for additive technologies of the set particle size distribution by regulation of the modes of consecutive processes was considered. It was established the influence of remelting of initial materials on the rate of absorption of hydrogen and hydrogen fragility of titanium alloys. Experiments confirmed that the presence of coarse-grained structure accelerates the hydrogenation process. The optimum modes of hydrogenation and dehydrogenation allowing to reduce the particle quantity with sizes less than 10 microns were developed (in the case of obtaining titanium hydride with content of hydrogen 3.4–3.5% by weight). Negative influence of fraction 10 microns on powder characteristics was revealed: increase the ability of the spherical particles to stick together, formation of satellites and aggregates, reduction of powder flowability. It was considered the possibility of using gas centrifugal classification in the inert atmosphere with the purpose to reduce the particle quantity of less than 10 microns in size. Application of classifying equipment allowed to reduce this amount up to 0.5%.

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