Crystallography and anisotropy of crystals shape in dense aluminum titanate ceramics

This study investigates the anisotropic grain growth of Fe-doped aluminum titanate ceramics using Electron Backscatter Diffraction (EBSD). Three grades of materials exhibiting various grain size distributions were prepared on the basis of different sintering conditions. The crystal structure of the raw powder was first refined using X-ray diffraction. Then the microstructure variation of sintered polycrystalline aluminum titanate associated to anisotropic grain coarsening was accurately studied. Due to the orthorhombic structure of beta-Al2TiO5, the crystal shape is prismatic and elongated along the [100] direction. This specific grain shape is analyzed in relation with crystallographic axes in the frame work of the Wulff approach. The obtained results provide valuable information regarding the microstructure of such flexible ceramics made off anisotropic grains.