Preparation of alumina ceramic template by the molten salt method

Single-crystal alpha alumina (α-Al2O3) platelets were synthesised with aluminium sulphate in the study. Moreover, the effects of the heating temperature, holding time, and different power mixtures of γ-Al2O3 and sodium sulphate (Na2SO4) on the morphology of as-prepared α-Al2O3 platelets were explored. The crystalline phase evolution and morphology of the samples were characterised by X-ray diffraction and scanning electron microscopy. According to the further analysis results, most of α-Al2O3 platelets were hexagonal particles. After the power mixture of γ-Al2O3 and Na2SO4 (1:2) was heated at 1200°C for 1 h, the platelet size became relatively uniform with an average diameter of 3–5 μm and a thickness of 50–100 nm. This method is an easily controllable, simple, and green method to produce high-quality α-Al2O3 platelets.