Uniformly porous MgTi2O5 with narrow pore-size distribution: in situ processing, microstructure and thermal expansion behavior

Porous ceramics based on refractory double oxides are promising for light-weight structural components and high-temperature filter materials. In this study, porous MgTi2O5 ceramics with pseudobrookite-type structure have been prepared by in situ processing (viz. reactive sintering). High-temperature XRD revealed the in situ reaction behavior of the mixed powder, and indicated suitable sintering temperatures to obtain single phase MgTi2O5 (≥1000°C). Uniformly porous MgTi2O5 ceramics with very narrow pore-size distribution at the diameter of ∼1 µm were obtained by the pyrolytic reactive sintering at 1000–1200°C, where decomposed CO2 gas from a carbonate source acted as an intrinsic pore forming agent. Thermal expansion behavior of bulk porous MgTi2O5 (porosity: 42%) is also discussed.