Piezoelectric properties of novel oriented ceramic-polymer composites with 2-2 and 3-3 connectivity

The processing of novel 2-2 and 3-3 PZT ceramic-polymer composites with various orientation of the ceramic phase with respect to the poling direction is presented. The volume fraction of the ceramic was chosen to be 30 percent for both types of composites. The orientation angle (theta) of the ceramic phase varied between 0degrees and 75degrees for both types of composites with 15degrees increments. The ceramic structures were fabricated using one of the Solid Freeform Fabrication (SFF) methods, particularly Fused Deposition of Ceramics (FDC). The sintered structures were embedded in hard epoxy and the effect of orientation angle on the electrical properties of the composites was evaluated. By increasing the orientation angle of the ceramic phase, the dielectric constant and the piezoelectric strain coefficient of both types of composites decreased. Although the piezoelectric voltage coefficient of the 2-2 composites showed a minor improvement with increasing theta at 45degrees, the g(33) value of the 3-3 composites increased considerably with theta and reached 80 mV/N at theta = 45degrees. Further increase of the orientation angle reduced the g(33) of such composites.