Research Information System
Conference on Better Ceramics Through Processing, CIRENCESTER, United Kingdom, 21 - 22 April 1998, pp.93-101
Nano-sized mullite matrix precursors comprising individually a mixture of a boehmite sol and one of a series of amorphous fumed silica powders in aqueous suspension were characterised in terms of particle size, particle size ratio, rheological behaviour and solids-loading. Particle mobility measurements and transmission electron microscopy (TEM) were employed to determine the heterocoagulated particle's net surface charge and the nano-scale alumina-silica particle interaction behaviour, respectively. The final nano-scaled suspension was optimised to obtain a heterocoagulated mullite precursor sol useful for the fabrication of fibre-reinforced mullite nano-ceramic matrix composites (CMCs) using electrophoretic filtration deposition (EFD). It has been shown that a nano-sized suspension having a solids-loading as high as 30 wt% under stable conditions can be prepared if the short-range particle-particle interactions are well controlled.