Effect of Carbon Source on Crystal Morphology of SiC in-situ Formed in AI_2O_3-Si-C Matrix  

作　　者：LIANG Feng LI Nan LIU Baikuan HE Zhongyang 

机构地区：[1]The State Key Laboratory of Refractories and Metallurgy,Wuhan University of Science and Technology [2]Puyang Refractories Group Co.,Ltd.

出　　处：《China's Refractories》2015年第2期11-15,共5页中国耐火材料（英文版）

基　　金：financially supported by National Basic Research Program of China ( 973 Program , 2012CB722702 )

摘　　要：Three kinds of Al2O3- Si- C matrix specimens were prepared using tabular corundum powder and Si powder as starting materials,ultrafine flake graphite,nano carbon black,and carbon nanotubes as carbon sources,respectively,to research the effect of micro or nano carbon materials on structure and morphology of formed Si C crystals. The specimens were fired at 1 000,1 200 and 1 400℃ for 3 h in carbon-embedded condition,respectively.The phase composition was studied by XRD and the crystal morphology of Si C was investigated by FESEM. The results show that：（ 1） the amount of Si C increases with the firing temperature rising;（ 2） the in-situ reaction mechanism and the formed Si C crystal morphology vary with carbon source： carbon nanotubes are generally converted into Si C whiskers by carbon nanotubes-confined reaction; Si and nano carbon black react to nucleate quickly,and the nucleated Si C crystals grow evenly in all directions forming Si C particles; Si C whiskers are produced from edge to internal of ultrafine flake graphite.Three kinds of Al2O3- Si- C matrix specimens were prepared using tabular corundum powder and Si powder as starting materials,ultrafine flake graphite,nano carbon black,and carbon nanotubes as carbon sources,respectively,to research the effect of micro or nano carbon materials on structure and morphology of formed Si C crystals. The specimens were fired at 1 000,1 200 and 1 400℃ for 3 h in carbon-embedded condition,respectively.The phase composition was studied by XRD and the crystal morphology of Si C was investigated by FESEM. The results show that：（ 1） the amount of Si C increases with the firing temperature rising;（ 2） the in-situ reaction mechanism and the formed Si C crystal morphology vary with carbon source： carbon nanotubes are generally converted into Si C whiskers by carbon nanotubes-confined reaction; Si and nano carbon black react to nucleate quickly,and the nucleated Si C crystals grow evenly in all directions forming Si C particles; Si C whiskers are produced from edge to internal of ultrafine flake graphite.

关 键 词：alumina-silicon-carbon ultrafine flake graphite nano carbon black carbon nanotubes silicon carbide whiskers in-situ reaction 

分 类 号：TQ175.1[化学工程—硅酸盐工业] TQ127.11