Effect of AlF3 Content on Microstructure and Properties of Mullite/Al2O3 Composite Ceramics
To reinforce the mullite/Al2O3 composite ceramics through formation of mullite whiskers, the composite ceramics were prepared by pressureless sintering using different AlF3 content. The microstructure, porosity, fracture toughness and thermal shock resistance of the composite ceramics were investigated. The results show that the addition of AlF3 can promote the mullite whisker formations, and the whiskers with the size of 3～10μm in diameter and a length-diameter ratio of 10～15 are obtained by sintering at 1600°C with the AlF3 content of 5wt%. Fracture toughness and thermal shock resistance of the composite ceramics are improved by the formation of mullite whisker. The fracture toughness of 4.79MPa•m1/2 can be obtained, and the 95.18% flexural strength remained after thermal shock.
Junichi Hojo, Tohru Sekino, Jian Feng Yang, Hyung Sun Kim and Wen Bin Cao
K. Z. Sang et al., "Effect of AlF3 Content on Microstructure and Properties of Mullite/Al2O3 Composite Ceramics", Materials Science Forum, Vol. 922, pp. 62-67, 2018