This proposal outlined two novel but "intelligent" applications of the piezoelectric phenomena in ceramics and ceramic composites. One utilizes the piezoelectric effect in the detection of stresses and cracks in monlithic ceramics and ceramic composites. It will also prevent cracking and crack growth as a result of the piezoelectrically generated compressive forces. the other application utilizes the piezoelectric effect to produce forces, either compressive or tensile, on fiber-matrix interfaces in order to modify the fiber-matrix interfacial shear strenths in the ceramic composites. Special tape-casting and laminating technique will be used to produce the monolithic BaTiO3 ceramics and the uniaxially-reinforced sapphire fiber BaTiO3 matrix composites. This proposed program will provide fundamental understanding of the synthesis of "intelligent" ceramics and ceramic matrix composites and their properties. %%%% This program outlined two "intelligent" applications of the piezoelectric phenomena in ceramics and ceramic matrix composites. One uses the piezoelectric effect to detect stresses and cracks and to use the piezoelectrically generated forces to prevent cracking and crack growth. The other uses the effect to produce forces on the fiber-matrix interfaces and to modify shear strengths through them. Special tape-casting and laminating technique will be used to produce the BaTiO3 ceramics and uniaxially-reienforced sapphire fiber BaTiO3 matrix composites. This study will provide fundamental understanding of the synthesis and "intelligent" ceramics and ceramic matrix composites and their properties. Potential commercial applications can be enormous and wide-ranged into many industrial sectors.
