Fabrication, Microstructure and Mechanical Properties Relations of Ferroelectric Barium Titanate Reinforced with Alumina Micro/Nano Particulates
The effects of reinforced alumina particulates on some properties of ferroelectric barium titanate ceramics were investigated. BaTiO3/xAl2O3 powders where x = 0, 3, 5, 10 and 15 mol% were prepared by a solid-state mixed-oxide method. The starting alumina particle sizes used were about 10 μm and 40 nm for the preparation of composite and nanocomposite ceramics, respectively. Phase characterization by XRD suggested that the reaction between BaTiO3 and Al2O3 occurred during sintering and resulted in BaAl2O4 and Ba4Ti10Al2O27 phases accompanying the main BaTiO3 phase. The densities of the ceramics were found to decrease with increasing content of Al2O3 dispersoid. Average grain size was also reduced with increasing amount of alumina addition. The BaTiO3/Al2O3 nanocomposite ceramics at every composition contained smaller grains compared with the normal composite ceramics which seemed to be the main governing factor that caused higher hardness and lower fracture toughness in the nanocomposites.
S. Jiansirisomboon et al., "Fabrication, Microstructure and Mechanical Properties Relations of Ferroelectric Barium Titanate Reinforced with Alumina Micro/Nano Particulates", Advances in Science and Technology, Vol. 45, pp. 2406-2411, 2006