Advanced Oxide Ceramics from a Preceramic Polymer and Fillers

Advanced oxide ceramics (mullite and wollastonite) have been obtained using a silicone resin plus inorganic or organo‐metallic fillers. Highly dense and crack‐free mullite samples were prepared, in the temperature range 1200–1500°C, by oxidation of the silicone resin, mixed with alumina nano‐particles. A large mullite yield was achieved even at low firing temperature (1250°C), due to the high reactivity of nanometric inclusions towards the silica provided by the polymer. The addition of calcined clay as secondary filler allowed mullitization already at 1200°C. Biocompatible wollastonite ceramics, based on mixtures of both low temperature phase (β‐CaSiO₃) and high temperature phase (α‐CaSiO₃) were developed from the pyrolysis in nitrogen of silicone filled with Ca‐acetate. The phase assemblage could be tailored by varying the pyrolysis heat treatment. The use of filled silicones for the development of advanced ceramics appears particularly promising, since shaping of complex components can be obtained using polymer processing techniques.

Keywords:

• Fillers
• Preceramic polymers
• Nano powders