Preparation of ZrB₂ and ZrB₂-SiC powders in a single step reduction of zircon (ZrSiO₄) with B₄C

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• 作者：R.V. Krishnarao ^{rvkr4534@yahoo.com" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Zircon (ZrSiO4) ; ZrB2 ; SiC ; Composites ; Synthesis
• 刊名：Ceramics International
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：43
• 期：1
• 页码：1205-1209
• 全文大小：1520 K

文摘

The reduction of zircon (ZrSiO₄) with C and B₄C results in the formation of impurity phases like ZrO₂, ZrC, ZrSi, SiO₂, SiC and borosilicate. Synthesis of pure ZrB₂ by eliminating SiO₂ in ZrSiO₄ in a single step reduction with B₄C has been studied. Without adding free carbon, zircon was reduced with B₄C in different weight ratios (ZrSiO₄/B₄C=1.6/2.5/3.3) at different temperatures between 1300 °C and 1600 °C in argon. The ratio of ZrSiO₄/B₄C and reaction temperature were optimized to produce a single phase ZrB₂ free from impurity phases. Addition of carbon or B₄C to an optimized mixture of (ZrSiO₄/B₄C=3.3) has resulted in the formation of (ZrB₂-SiC) composite powder. Composite powders of (ZrB₂-SiC) and (ZrB₂-SiC-B₄C) were formed by increasing the B₄C content to ZrSiO₄/B₄C=2.5 and 1.6 respectively.