The effect of starting powder on the microstructure development of alumina–aluminum titanate composites

The effect of starting powder on Al2TiO5 morphology and grain growth of Al2O3 was investigated in alumina–aluminum titanate composites using Al2O3, TiO2 and calcined Al2TiO5 as starting powders. Depending on the composition of starting powders, various Al2TiO5 morphologies, such as rod-like, polyhedron-like, and irregular shape were observed. When Al2O3 and TiO2 were used as starting powder, the rod-like shape and the irregular shape of Al2TiO5 were observed. In the addition of calcined Al2TiO5 as starting powder, however, the polyhedron-like shape and the irregular shape of Al2TiO5 were observed. When the starting powder was consisted of Al2O3 and TiO2, alumina-aluminum titanate composites provided more narrow size distribution and smaller average size of Al2O3 grains compared to those consisting of Al2O3 and Al2TiO5.