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Low‐Temperature Synthesis of ZrC Powder by Cyclic Reaction of Mg in ZrO 2 –Mg–CH 4
Author(s) -
Kobayashi Hidehiko,
Shimosaka Kenichi,
Saitoh Miki,
Mitamura Takashi
Publication year - 1993
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1993.tb07785.x
Subject(s) - molar ratio , thermite , decomposition , materials science , reaction rate , nuclear chemistry , reaction conditions , chemistry , inorganic chemistry , catalysis , metallurgy , organic chemistry , aluminium
We investigated the conditions for low‐temperature synthesis of ZrC fine powder from ZrO 2 –Mg–CH 4 . The synthesis utilizes a thermite‐type reaction, with Mg as the reducing agent, and a reaction between Mg and CH 4 gas as a carbon source. The Mg/ZrO 2 molar ratio as well as the heating rate were varied. Because C can be continuously fed into the reaction group by the cyclic reaction of Mg through the formation and decomposition of Mg 2 C 3 (2Mg + 3CH 4 → Mg 2 C 3 + 6H 2 → 2Mg + 3C), a molar ratio of 2.2 for Mg/ZrO 2 was sufficient for the synthesis of single‐phase ZrC. ZrC powders were synthesized under the following conditions: Mg/ZrO 2 molar ratio = 2.2, heating rate = 20°C/min, and temperature maintained at 750°C for 30 min. The amount of reaction heat produced in the reduction reaction of ZrO 2 by Mg depended on the Mg/ZrO 2 molar ratio, specifically, the amount of ZrO 2 contained. Moreover, the cyclic reaction of Mg‐Mg 2 C 3 –Mg was influenced by the amount of reaction heat described above and by the heating rate. The ZrC fine powder showed little aggregation and high dispersibility.