Fabrication and Properties of CaAl₁₂O₁₉-Al₂O₃ Composite Ceramics

Abstract:

CaAl₁₂O₁₉-Al₂O₃ composite ceramics were synthesized by in situ solid state reaction using CaCO₃ and industrial α-Al₂O₃ powders. The effects of sintering temperature and ratio of CA₆ (CaAl₁₂O₁₉) content on phases and microstructure of the final composite ceramics were studied by XRD and SEM. The result showed that sheet-like CA₆ appeared in the materials when sintering temperature was higher than 1400°C and grew up with the increased of the sintering temperature. The optimum sintering temperature was 1600°C, when the sample containing 20wt% CA₆ was sintered at 1600°C, the bulk density was 3.21g/cm³, the apparent porosity achieved 9.94% and the bending strength gained 149.88MPa. With the increasing of CA₆ content in the final composite ceramics, the bulk density and the bending strength increased firstly and then decreased. The lowest apparent porosity 1.42%, a density of 3.60g/cm³ and the highest bending strength of 265.10MPa were achieved for the sample containing 10wt% CA₆ sintered at 1600°C.

• Periodical: Key Engineering Materials (Volumes 512-515)
• Pages: 539-542
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.512-515.539
• Online since: June 2012
• Authors: Xue Yin Liu, Yan Gai Liu, De Xin Yang, Ding Yun Ye, Zhao Hui Huang, Ming Hao Fang
• Keywords: CaAl₁₂O₁₉-Al₂O₃, In Situ Solid State Reaction, Sheet-Like Crystal

References

[1] X. He, X.G. Zhou, B. Su, 3D interconnective porous alumina ceramics via direct protein foaming. Mater. Lett., 63 (2009) 830-832.

DOI: 10.1016/j.matlet.2008.12.021

[2] B. Hallstedl, Assessment of the CaO-Al2O3 system, J. Am. Ceram. Soc. 73 (1990) 15-23.

[3] C. Dominguez, R. Torrecillas, Influence of Fe3+ on sintering and microstructural evolution of reaction sintered calcium hexaluminate, J. Eur. Ceram. Soc. 18 (1998) 1373-1379.

DOI: 10.1016/s0955-2219(98)00067-3

[4] C. Domínguez, J. Chevalier, R. Torrecillas, et al. Microstructure development in calcium hexaluminate, J. Eur. Ceram. Soc. 21 (2001) 381-387.

[5] A. Altay, C.B. Carter, P. Rulis, et al. Characterizing CA2 and CA6 using ELNES, J. Solid State Chem. 183 (2010) 1776-1784.

DOI: 10.1016/j.jssc.2010.05.028

[6] K.W. Harr, R. J. Mangabhai, F. P. Glasser, Relationship between mineral phase C4AF and CA in CAC with a high iron content, Proc. Int. Conf. Calcium Aluminate Cements (2001) 121-127.

[7] B. Venkateshwaran, M.W. Yao, R.Y. Guo, et al. Low temperature dielectric properties of magnetoplumbite family of materials, Int. J. Inorg. Mater. 1  (1999) 213-217.

DOI: 10.1016/s1466-6049(99)00033-1