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Synthesis of Calcium Hexaboride Powder via the Reaction of Calcium Carbonate with Boron Carbide and Carbon
Author(s) -
Zheng Shuqi,
Min Guanghui,
Zou Zengda,
Yu Huashun,
Han Jiande
Publication year - 2001
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.1151-2916.2001.tb01083.x
Subject(s) - boron carbide , scanning electron microscope , carbon fibers , boron , calcium carbonate , raw material , materials science , phase (matter) , carbide , chemical engineering , calcium , chemistry , mineralogy , metallurgy , composite material , composite number , organic chemistry , engineering
The synthesis of calcium hexaboride (CaB 6 ) powder via the reaction of calcium carbonate (CaCO 3 ) with boron carbide (B 4 C) and carbon has been investigated systematically in the present study. The influences of heating temperature and holding time on the reaction products have been studied using X‐ray diffractometry, and the morphologies of CaB 6 obtained at various temperatures and holding times have been investigated via scanning electron microscopy. The interaction in the CaCO 3 –B 4 C–carbon system by which CaB 6 is formed is a solid‐phase process that passes through the transition phases Ca 3 B 2 O 6 and CaB 2 C 2 . The optimal conditions for CaB 6 synthesis are a holding time of 2.5 h at a temperature of 1673 K, under vacuum (a pressure of 10 −2 Pa). CaB 6 powder has the same morphology as B 4 C, and the properties and the shape of CaB 6 powders can be improved by choosing good‐quality raw materials.