Trisodium phosphate (Na3PO4 center dot 12H(2)O) and titanyl sulfate (TiOSO4) were chosen to study the influence of additives on the morphology of alpha-Al2O3 platelets synthesized by molten salt synthesis. When Na3PO4 center dot 12H(2)O is added, alpha-Al2O3 platelets become thin and quite irregular. Besides, less overlapped particles can be found. When TiOSO4 is added, regular hexagonal alpha-Al2O3 platelets with a decreased size and increased thickness are obtained. When 0.51 wt% Na3PO4 center dot 12H(2)O and 12 wt% TiOSO4 are added, alpha-Al2O3 platelets with a regular shape and an aspect ratio of 12.5 are developed. The mechanism of Na3PO4 center dot 12H(2)O and TiOSO4 on the morphology of alpha-Al2O3 platelets is also discussed in this paper.

Keywords: Platelets; alpha-Al2O3; Molten salt synthesis; Additives