Combustion Synthesis of Nanosized -SiC Powder on a Large Scale

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• 作者：Guanghua Liu ; Kun Yang ; Jiangtao Li ; Kun Yang ; Jisheng Du ; Xiaoyi Hou
• 刊名：Journal of Physical Chemistry C
• 出版年：2008
• 出版时间：April 24, 2008
• 年：2008
• 卷：112
• 期：16
• 页码：6285 - 6292
• 全文大小：772K
• 年卷期：v.112,no.16(April 24, 2008)
• ISSN：1932-7455

文摘

Nanosized mages/gifchars/beta2.gif" BORDER=0 ALIGN="middle">-SiC powder was prepared by combustion synthesis on a large scale, which was carried out ina N₂ atmosphere with silicon powder and carbon black as the reactants. Mechanical activation played animportant role in enhancing the reactivity of the reactants, and a higher ball/charge weight ratio and a prolongedactivation time were favorable for complete reaction. PTFE was added as a reaction promoter, which remarkablyreduced the minimum activation time required for successful combustion synthesis. On the basis of experimentalresults and thermodynamical calculation, it is proposed that combustion synthesis of SiC in N₂ includes twosteps: (1) Si reacts with N₂ to form Si₃N₄, generating a lot of heat energy; (2) at higher temperatures theinitially formed Si₃N₄ decomposes, and released Si reacts with carbon to produce SiC.