Mullite whiskers were novelty prepared via pressure field assisted polycondensation nonaqueous precipitation method. The precipitate phase transition in heating process, phase compositions and microstructure of samples calcined at different temperatures, effect of pressure field on precursors polycondensation and AlF₃ amount on sample morphology, the structure and the growth mechanism of whiskers were investigated. The results indicate that pressure field caused by kettle treatment promotes the polycondensation reaction between AlF₃ and tetraethyl orthosilicate (TEOS), the excess aluminum fluoride coordinates with the precipitate skeleton of the =Al–O–Si≡, which brings about the low mullitization temperature (900 °C). The sample prepared with the optimal amount of aluminum fluoride (1.3 of the theoretical amount) calcined at 1100 °C presents high yield and aspect ratio (>15, 100 nm in diameter) of mullite whiskers. Growth of whiskers prepared via pressure field assisted polycondensation nonaqueous precipitation method is attributed to a vapor-solid (VS) mechanism with the inducement of screw. These mullite whiskers with the structure of multi-needle whiskers connected in the same center can be distributed evenly in epoxy resin, which greatly improves the mechanical properties of epoxy resin.

Novel yellow to blackish green Ni-doped aluminium titanate (Al2TiO5) ceramic pigments were synthesized by solid-state reaction method at 1400 ?C. Effects of nickel doping content on phase composition, microstructure, optical properties and stability were studied. The results show that the higher content of Al2TiO5 phase and the reduction of the lattice distortion of aluminium titanate could be attributed to the entry of nickel ions into aluminium titanate lattice resulting in the formation of solid solution. Ni-doped aluminium titanate ceramic pigments show exceptional glaze colouring and are expected to be promising high-temperature pigments.