Production of finely dispersed titanium powder by volumetric reduction of its ions with sodium dissolved in the BaCl2–CaCl2–NaCl melt
Электронный научный архив УРФУ
Информация об архиве | Просмотр оригинала| Поле | Значение | |
| Заглавие |
Production of finely dispersed titanium powder by volumetric reduction of its ions with sodium dissolved in the BaCl2–CaCl2–NaCl melt
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| Автор |
Lebedev, V. A.
Polyakov, V. V. |
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| Тематика |
ADDITIVE TECHNOLOGIES
CURRENT EFFICIENCY CURRENT EFFICIENCY ESTIMATION BY THE AVERAGE VALENCE OF TITANIUM IONS IN THE ANODE LAYER ELECTROLYTIC VOLUMETRIC REDUCTION OF TITANIUM GRAIN SIZE ANALYSIS MICROGRAPHS ULTRASONIC MILLING X-RAY PHASE ANALYSIS |
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| Описание |
The research is intended to develop a technology for the production of finely dispersed (10 to 100 μm) powders of titanium and its alloys suitable for use in additive technologies after classification and spheroidization. A eutectic mixture was used as electrolyte, mole fractions: BaCl2 – 0.16, CaCl2 – 0.47, NaCl – 0.37, melting point of 452 °C. Electrolytes with a similar composition are used in industry for the electrolytic production of sodium with high current efficiency. No titanium salts were added to electrolyte. Sodium losses due to evaporation, corrosion, and ion recharge were replenished by a periodic increase in electrolysis current. A VT1-0 titanium plate was used as an anode. The walls of a steel crucible served as a cathode. Sodium was released on these walls and dissolved in electrolyte. Titanium ions were reduced in the bulk of electrolyte and in the anode layer. It is the first time that the results obtained were interpreted using the data on the electrode potentials of Ti3+/Ti, Ti2+/Ti, Ti3+/Ti2+ systems. It was shown that the concentration of slowly moving complex Ti3+ ions increases in the anode layer, and sodium dissolved in electrolyte reduces mainly Ti2+ ions in the electrolyte volume in the first 12 min of electrolysis. Starting from the 20th min, the concentration of Ti2+ ions in the anode layer begins to increase rapidly according to the reaction: 2Ti3+ + Ti = 3Ti2+ as titanium powder accumulates in the electrolyte volume. At the same time, the proportion of sodium consumed for the reduction of Ti3+ ions to Ti2+ decreases, which contributes to an increase in current efficiency and cathode potential stabilization for 30 minutes at –2.963 V. After the 50th min, the reactivity of the salt melt begins to decrease, the concentration of Ti3+ ions increases steadily until it levels off with the concentration of Ti2+ ions at the 85th min. This sharply increased the current consumption for ion recharge and made it necessary to stop electrolysis after switching on a current of 12 A for a short time (for 40 s). After 10 s, judging by the change in the cathode potential, sodium dissolved in electrolyte was almost completely consumed for titanium ion reduction. After 6 min, the potentials of electrodes returned to the initial anode potential value indicating that the system returned to its original state with the near-zero content of titanium salts and dissolved sodium. 95 % of powder was obtained in the electrolyte volume. Current efficiency was 84.0 % and turned out to be close to the value calculated from the average valence of titanium ions and the loss of anode weight (87.0 %). After ultrasonic dispersion, more than 80 % of powder was in the 10–100 μm range with a maximum at 36 μm. X-ray phase analysis showed that this is practically pure α-titanium (93.06 %) and oxygenated α-titanium (5.45 %). The originality of the research consists in the use of a volumetric, intensive, electrolytic method for producing finely dispersed titanium powders with no dissolved sodium and titanium chlorides in the initial and final electrolytes, in a stepwise increase in the current and potentiometric process control. The uniqueness of the research consists in the titanium powder obtained where the major part is in the melt volume in the form of intergrowths that are easily crushed by ultrasonic dispersion into individual crystals. Over 80 % of these crystals were in the range of 10–100 μm required for additive technologies with an average size of 36 μm. © 2022 Izvestiya Vuzov. Poroshkovaya Metallurgiya i Funktsional'nye Pokrytiya.
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| Дата |
2024-04-08T11:05:59Z
2024-04-08T11:05:59Z 2022 |
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| Тип |
Article
Journal article (info:eu-repo/semantics/article) Published version (info:eu-repo/semantics/publishedVersion) |
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| Идентификатор |
Лебедев, ВА & Поляков, ВВ 2022, 'Получение тонкодисперсного порошка титана объемным восстановлением его ионов натрием, растворенным в расплаве BaCl2–CaCl2–NaCl', Известия высших учебных заведений. Порошковая металлургия и функциональные покрытия, Том. 16, № 1, стр. 4-16. https://doi.org/10.17073/1997-308X-2022-1-4-16
Лебедев, В. А., & Поляков, В. В. (2022). Получение тонкодисперсного порошка титана объемным восстановлением его ионов натрием, растворенным в расплаве BaCl2–CaCl2–NaCl. Известия высших учебных заведений. Порошковая металлургия и функциональные покрытия, 16(1), 4-16. https://doi.org/10.17073/1997-308X-2022-1-4-16 1997-308X Final All Open Access; Green Open Access https://powder.misis.ru/jour/article/download/669/379 https://powder.misis.ru/jour/article/download/669/379 http://elar.urfu.ru/handle/10995/131248 48076840 10.17073/1997-308X-2022-1-4-16 85136604181 |
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| Язык |
ru
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| Права |
Open access (info:eu-repo/semantics/openAccess)
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| Формат |
application/pdf
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| Издатель |
Izdatel'stvo Kalvis
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| Источник |
Izvestiya vuzov. Poroshkovaya metallurgiya i funktsional’nye pokrytiya
Izvestiya Vuzov. Poroshkovaya Metallurgiya i Funktsional'nye Pokrytiya |
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