Abstract: Aiming at investigating the preparation and formation mechanism of magnesium aluminate spinel whisker, the present work utilized fused magnesia (≤0.074 mm), α-Al2O3(d50=2.5 μm) and flake graphite (≤0.15 mm) as main raw materials and applied a carbon-embedded heat-treatment process at 1 550 ℃ for 3 h to synthesize fibroid whisker-like MgAl2O4, whose phase composition and microstructure were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), and energy dispersive X-ray spectroscopy (EDS), respectively. The results confirmed the spinel phase of the resultant whiskers with the length of up to 10 mm and an average diameter ranging from 5 μm to 20 μm. The spinel whiskers exhibit sharp terminals, and some of the whiskers have branches. The mutual presence of alumina and graphite can lead to a relatively large amount of spinel whiskers. It can also be concluded that the vapor-solid (V-S) mechanism dominates the in-situ growth of the magnesium aluminate spinel whiskers.
1 Baudin C, Martinez R, Pena P. High-temperature mechanical beha-vior of stoichiometric magnesium spinel[J].Journal of the American Ceramic Society,1995,78:1857. 2 Tripathi H S, Ghosh A. Spinelisation and properties of Al2O3-MgAl2O4-C refractory: Effect of MgO and Al2O3 reactants[J].Ceramics International,2010,36(4):1189. 3 Lei Muyun, Huang Cunxin, Wen Fang. Development of transparent ceramic spinel[J].Journal of Synthetic Crystals,2007,36(2):319(in Chinese). 雷牧云,黄存新,闻芳.透明尖晶石陶瓷的研究进展[J].人工晶体学报,2007,36(2):319. 4 李楠,顾华志.耐火材料学[M].北京:冶金工业出版社,2002:185. 5 Mazzoni A D, Sainz M A, Caballero A, et al. Formation and sintering of spinels (MgAl2O4) in reducing atmospheres[J].Materials Chemistry and Physics,2003,78(1):30. 6 Xie Zhaohui, Ye Fangbao. In-situ formation of spinel fibers in MgO-C refractory matrixes[J].Journal of Wuhan University of Technology-Materials Science Edition,2009,24(6):896. 7 Zhu Boquan, Wei Guoping.et al. In-situ catalytic growth of MgAl2O4 spinel whiskers in MgO-C refractories[J].International Journal of Materials Research,2014,105(6):593. 8 Zhu Tianbin, Li Yawei, Sang Shaobai. et al. Formation of hollow MgO-rich spinel whiskers in low carbon MgO-C refractories with Al additives[J].Journal of the European Ceramic Society,2014,34(16):4425. 9 Hashimoto S, Yamaguchito A. Synthesis of MgAl2O4 whiskers by an oxidation-reduction reaction[J].Journal of the American Ceramic Society,2010,79(2):491. 10 杨南如.无机非金属材料测试方法[M].武汉:武汉理工大学出版社,1993:70. 11 Pei Chunqiu, Shi Gan. Influence of the composition on MA spinel properties[J].Journal of Wuhan University of Science and Technology,2012(3):207(in Chinese). 裴春秋,石干.材料组成对镁铝尖晶石化行为的影响[J].武汉科技大学学报,2012(3):207. 12 Qi Haitao, Zhang Li. Ultra-long AlN crystal grown by physical vapor transport method[J].Bulletin of the Chinese Ceramic Society,2014,33(4):816(in Chinese). 齐海涛,张丽.气相传输法生长超长AlN晶须[J].硅酸盐通报,2014,33(4):816. 13 陈肇友.化学热力学与耐火材料[M].北京:冶金工业出版社,2005:480. 14 梁英教,车荫昌.无机物热力学手册[M].沈阳:东北大学出版社,1993:442. 15 许越.化学反应动力学[M].北京:化学工业出版社,2004:114.
渝公网安备50019002502923号 版权所有：《材料导报》编辑部
2018, Vol. 32 
