Microstructure and microcracking behaviour of barium zirconium phosphate (BaZr4P6O24) ceramics

Barium zirconium phosphate (BaZr4P6O24), a member of a new family of low-thermal-expansion materials known as NZP, was synthesised by the solution sol-gel method, and sintered ceramics were prepared at 1100-1600 C. The effect of sintering parameters such as time and temperature on the microstructure and phase composition was studied. BaZr4P6O24 is known to possess anisotropy in its axial thermal expansions, which usually causes microcracking in the sintered bodies when cooled. The microcracking activity of the sintered samples was examined by acoustic emission measurements. 17 refs.