| Composites of lead zirconate-titanate (PZT) and polymers have been shown to have outstanding properties compared to PZT for hydrostatic sensing applications. Most work in the past has dealt with manipulations of the composite design, ceramic composition, or polymer type. The role of interfacial adhesion between the PZT and the polymer in these composites had not been examined in any depth.; For this reason, interfacial adhesion in PZT/epoxy composites was determined by mechanical tests and found to be far from optimum. A number of PZT surface treatments such as physical surface roughening and coupling agent treatments were found to increase the degree of adhesion by a factor of 2-3 times that of PZT. Furthermore, the interfacial strengths were so substantial in some cases that cohesive failure of the epoxy occurred.; In addition, 1-3 PZT/Spurr epoxy composites were fabricated with poor, intermediate, and good interfacial adhesion, respectively. The piezoelectric properties were found to be significantly affected by the level of adhesion. The (')d(,h), g(,h), and (')d(,h)g(,h) were found to be 25%, 57%, and 100% higher, respectively, for composites with good adhesion than for those with poor ceramic-polymer interfacial strengths.; Finally, the pyroelectric response of several 1-3 PZT/polymer composites was measured. The pyroelectric coefficients (p) were found to decrease (i.e., become more negative) as a function of increasing temperature. The figures of merit for composites were lower than that of PZT at room temperature, but were similar to or greater than the value for PZT at temperatures 50-80(DEGREES)C higher. |
