Effect of Sheet Nanocarbon on Properties of Low Carbon Al₂O₃-C Refractories

Abstract:

Sheet nanocarbon-Al₂O₃ composite powders were produced by vibratory milling using expanded graphite and Al₂O₃ powders as raw materials. The effect of different vibratory milling time on phase compositions and microstructure of the composite powders were investigated by X-ray diffraction (XRD), field emission scanning electron microscope (FESEM). Then sheet nanocarbon-Al₂O₃ composite powders were used as additives to produce low carbon Al₂O₃-C refractories which had a carbon content of 6%. The results showed that about 50nm thickness sheet nanocarbon and Al₂O₃ composite powders were produced via 15h milling with expanded graphite to Al₂O₃ powders weight ratio of 1:2. With the increasing of milling time, the (002) diffraction peaks of graphite wear off gradually and nanosheet was desquamated from expanded graphite; It is beneficial to improve the bulk density, cold modulus of rupture (CMOR) and thermal shock resistance of Al₂O₃-C refractories when adding certain sheet nanocarbon-Al₂O₃ composite powders. The sample containing 0.5% sheet nanocarbon had a CMOR of 18.51MPa after 1000 °C heat processing in N₂ atmosphere, while sample without adding any sheet nanocarbon was only 12.35MPa; The residual cold modulus of rupture (CMOR_TS) of sample containing 1% sheet nanocarbon was 4.22MPa after thermal shock test, while that of sample without nanocarbon was only 2.18MPa.

• Periodical: Materials Science Forum (Volumes 745-746)
• Pages: 642-645
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.745-746.642
• Online since: February 2013
• Authors: Xiao Xian Wu, Hong Xia Li, Guo Qi Liu, Chong Chong Niu, Tian Fei Ma
• Keywords: Expanded Graphite, Low Carbon Al₂O₃-C Refractories, Sheet Nanocarbon, Vibratory Milling

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