PROCESSING OF PIEZOCOMPOSITES BY FUSED DEPOSITION TECHNIQUE

Piezoelectric ceramic/polymer composites were made by a fused depositi on (FD) technique, which is a solid-freeform fabrication (or layered m anufacturing) technique where three-dimensional (3-D) objects are buil t layer by layer from a computer-aided design (CAD) file on a computer -controlled fixtureless platform, Indirect and direct FD methods were used to fabricate lead zirconate titanate (PZT)/polymer composites, Fo r the indirect method, a CAD file for the negative image of the final part was created, A polymer mold was made via FD using a thermoplastic filament, and composite formation was completed via a lost mold techn ique, In the direct FD method, a thermoplastic polymeric filament that was filled with 50-55 vol% of PZT powder was used to form a positive image of the desired structure. Three-dimensional honeycomb (''3-D hon eycomb'') composites and ''ladder'' composites with 3-3 connectivity, which were formed via the FD technique, showed excellent electromechan ical properties for transducer applications, In addition, the FD techn ique showed the ability to form composites with controlled phase perio dicity, various volume fractions, and a variety of microstructures and macrostructures that are not possible with traditional composite-form ing techniques.