CSIC developed a new and simple preparation process of lithium aluminosilicates with negative thermal expansion coefficients that requires inexpensive precursors (kaolin powders, lithium carbonate, etc.) and employs conventional and well known, within the ceramic industry, thermal and mechanical treatments. The result of this preparation procedure is an economic material with excellent thermal properties that combined with positive thermal expansion second phases allows the manufacture of composites with tailored, including null, CTE. Using this approach ceramic nanocomposite materials with non-oxidic second phases and showing a CTE lower than 1x10-6 K-1 in the temperature range (-150 ºC +150 ºC) can be obtained by a simple process that comprises conventional sintering methods, thus opening the possibility of manufacturing components with complex shapes and large dimensions. The patent portfolio also includes materials with only oxidic components and tailored thermal expansion coefficient, including materials with zero thermal expansion. These materials can be used in oxidizing atmospheres at elevated temperatures while maintaining excellent mechanical properties.

Whiskers  are  good  candidates  for  its use  as reinforcement phases in advanced  composites. Specifically,  single  crystal  alpha-Al2O3  whiskers  grown  with the  c-axis  orientation are suitable thanks to their  favorable  fracture  strength,  stiffness,  and  creep  resistance,  even  at  high  temperatures and oxidizing conditions.

Many defense applications demand ceramic nanocomposite materials combining several structural and functional properties only attainable with a tailored design of the microstructure and an adequate processing strategy that allows the consolidation of the materials into bulk-sized components while preserving the targeted microstructure, and particularly the nanoscale grain size. Incorporation of a small addition of metallic nano-particles improves the properties of polycrystalline oxide ceramics due to a mechanism of strengthening which is different when
compared to the mechanism attributed to metal particles of micrometric size.