The influence of different titanium sources on flaky α-Al2O3 prepared by molten salt synthesis

Flaky α-Al2O3 with different sizes and morphologies was synthetized by molten salt synthesis using Al2(SO4)3 as raw material. The formation mechanism of flaky alumina and the influence of different titanium-containing additives (TiOSO4, TBOT, and TiO2) on the growth of α-Al2O3 crystal were discussed by SEM, XRD and EDS. Results showed that pure α-Al2O3 can be obtained by adding all the three kinds of titanium-containing additives, but the diameters, thickness, and the morphologies of flaky α-Al2O3 were greatly affected by the different titanium sources. The adding of TiOSO4 additive resulted in the largest diameter of alumina platelets, while adding TiO2 additive would greatly reduce the diameters. The growth velocities of crystal planes in diameter and thickness direction were influenced by the distribution differences of the titanium ions, which resulted in different morphologies of alumina platelets. Diverse reaction routes for different titanium sources in preparation process were also discussed in this paper.