Preparation of aluminum borate whiskers by the molten salt synthesis method

A molten salt process was used to synthesize approximately single-phase aluminum borate (Al18B4O33) whiskers. The structure and morphology of Al18B4O33 whiskers were characterized by X-ray powder diffraction and scanning electron microscopy. The result showed that high-crystallized Al18B4O33 whiskers with an orthorhombic structure were obtained at 1000 °C. The diameter of Al18B4O33 whiskers synthesized at 1000 °C for 0.5 h was about 1.3 μm, and the lengths ranged from 50 μm to 150 μm. Instead of the well-known vapor–liquid–solid mechanism, a self-catalytic mechanism was used to explain the growth of the Al18B4O33 whiskers.