SOL-GEL CONTROL OF THE MICRO NANOSTRUCTURE OF FUNCTIONAL CERAMIC-CERAMIC AND METAL-CERAMIC COMPOSITES/

The problems encountered to tailor simultaneously various specific che mical or physical properties are discussed. Selected polymeric precurs ors used in association with fine powders allow the control of the nan o/microstructure of composites and hence the preparation of functional (FGM) and hierarchical reinforced (HRC) composites, making it possibl e to combine several kinds of fibers, interphases, and matrices in the same composite (hot microwave absorbent), to control the fiber/matrix interface (long life times composites), to achieve net-shape sinterin g of 3D composite matrices, and to prepare thick films of metal-cerami c composites with tailored microwave absorption (radar stealthiness).