Abstract:

Mullite whisker was prepared via nonhydrolytic Sol-Gel route using tetraethoxysilane and anhydrous aluminium chloride as precursors and ether as oxygen donor.The prepared mullite whisker is 0.2-2.0μm in diameter, with aspect ratio of 60-70. Effects of processing parameters on the mullite whisker were also studied by means of XRD, SEM and TEM, including activity of mullite xerogel, addition way and amount of mineralizer AlF₃, forming pressure and calcining temperature. The results indicate that the mullite xerogel prepared by the constant pressure reflux, transforms into the whisker with high yield and good quality after being shaped into disc at the pressure of 12MPa and calcined at 1200℃ for 1h with outside addition of 3wt% AlF₃.

Key words: non-hydrolytic Sol-Gel route, mullite, whisker, aspect ratio