Sintering, microstructural and dilatometric studies of combustion synthesized synroc phases

Sintering, microstructure, and linear thermal expansion properties of Synroc-B and constituent phases, viz. perovskite CaTiO3, zirconolite ZrTi2O7, hollandite (ideal formula BaA12Ti6O16) have been investigated. Synroc-B powder when pelletized and sintered at 1250 °C for 2 h achieved >95% theoretical density. Sintered Synroc-B has a linear thermal expansion coefficient a of 8.72 × 10−6 K−1 and Vickerʹs microhardness 9.88 GPa. The linear thermal expansion curves did not show any hystersis indicating the absence of microcracking in the sintered bodies.