本文選題：碳熱還原法 + 冰模板法��； 參考：《硅酸鹽學(xué)報》2017年12期

【摘要】：以六方氮化硼(h-BN)、氧化硼(B_2O_3)和石墨(C)為原料,去離子水為分散介質(zhì)、甲基纖維素(MC)為分散劑、聚乙烯醇(PVA)為結(jié)合劑,通過冰模板法以及碳熱還原過程制備了BN B4C復(fù)合多孔陶瓷。結(jié)合碳熱還原反應(yīng)過程的熱力學(xué)變化對產(chǎn)物進行分析。結(jié)果表明:當(dāng)燒結(jié)溫度為1 350℃時,熱力學(xué)計算得到反應(yīng)體系達到平衡時的CO分壓為1.45×10~6,此時產(chǎn)物的XRD結(jié)果中出現(xiàn)B4C新相,說明在1 350~1 550℃的燒結(jié)溫度和氮氣氣氛條件下,石墨可將B_2O_3還原成B4C,得到產(chǎn)物的體積密度和氣孔率分別為0.22、0.26、0.28 g·cm~( 3)和94.65%、92.24%、92.10%。產(chǎn)物的微觀結(jié)構(gòu)由直通孔結(jié)構(gòu)和部分樹枝狀孔結(jié)構(gòu)組成,這些多孔結(jié)構(gòu)為碳熱還原反應(yīng)產(chǎn)生的CO氣體逸出提供了快速通道。
[Abstract]:B4C composite porous ceramics were prepared by ice template method and carbothermal reduction process using hexagonal boron nitride (h-BN), boron oxide (BSP) and graphite (C) as raw materials, deionized water as dispersing medium, methyl cellulose (MC) as dispersant and polyvinyl alcohol (PVA) as binder. The products were analyzed in combination with the thermodynamic changes in the process of carbothermal reduction. The results show that when the sintering temperature is 1 350 鈩，

本文編號：1994704