Low‐Temperature Synthesis of Calcium Hexaboride Powder via Transient Boron Carbide Formation

Calcium hexaboride (CaB6) powder was synthesized by carbothermal reduction using a low-temperature synthesis method for boron carbide (B4C) powder. A B4C precursor consisting of boron oxide (B2O3) and carbon components was prepared from a condensed boric acid (H3BO3)-poly(vinyl alcohol) (PVA) product by thermal decomposition in air, which was then mixed with calcium carbonate (CaCO3) powder. CaB6 was formed via the transient formation of calcium borate (Ca3B2O6) and B4C, which were in close contact owing to the finely dispersed B2O3/carbon structure of the B4C precursor. CaB6 powder with fine particles was synthesized by heat treatment at 1400°C for 10 h in an Ar flow.

[1]  Masaki Kakiage,et al.  Effect of addition of tartaric acid on synthesis of boron carbide powder from condensed boric acid–glycerin product , 2013 .

[2]  Yusuke Tominaga,et al.  Effect of Molecular Structure of Polyols with Different Molecular Characteristics on Synthesis of Boron Carbide Powder , 2013 .

[3]  Rie Watanabe,et al.  Microstructure in precursor formed by controlling composition of condensed boric acid-poly(vinyl alcohol) product for low-temperature synthesis of boron carbide powder , 2013 .

[4]  Yusuke Tominaga,et al.  Synthesis of boron carbide powder in relation to composition and structural homogeneity of precursor using condensed boric acid–polyol product , 2012 .

[5]  Masaki Kakiage,et al.  Low-temperature synthesis of boron carbide powder from condensed boric acid–glycerin product , 2011 .

[6]  Masaki Kakiage,et al.  Effect of boron oxide/carbon arrangement of precursor derived from condensed polymer-boric acid product on low-temperature synthesis of boron carbide powder , 2011 .

[7]  Zhang Lin,et al.  Reaction mechanism and size control of CaB6 micron powder synthesized by the boroncarbide method , 2009 .

[8]  I. Yanase,et al.  Synthesis of boron carbide powder from polyvinyl borate precursor , 2009 .

[9]  Huashun Yu,et al.  The Size and Morphology of Fine CaB6 Powder Synthesized by Nanometer CaCO3 as Reactant , 2006 .

[10]  R. Telle,et al.  Phase transformation of transient B4C to CaB6 during production of CaB6 from colemanite , 2005 .

[11]  Shuqi Zheng,et al.  Synthesis of Calcium Hexaboride Powder via the Reaction of Calcium Carbonate with Boron Carbide and Carbon , 2001 .

[12]  E. T. Carlson.  The system: CaO-B2O3 , 1932 .