Piezoelectric and mechanical properties of structured PZT–epoxy composites

Abstract

Structured lead zirconium titanate (PZT)-epoxy composites are prepared by dielectrophoresis. The piezoelectric and dielectric properties of the composites as a function of PZT volume fraction are investigated and compared with the corresponding unstructured composites. The effect of poling voltage on piezoelectric properties of the composites is studied for various volume fractions of PZT composites. The experimentally observed piezoelectric and dielectric properties have been compared with theoretical models. Dielectrophoretically structured composites exhibit higher piezoelectric voltage coefficients compared to 0-3 composites. Structured composites with 0.1 volume fraction of PZT have the highest piezoelectric voltage coefficient. The flexural strength and bending modulus of the structured and random composites were analyzed using three-point bending tests.

High Piezoelectric Voltage Coefficient in Structured Lead‐Free (K,Na,Li)NbO3 Particulate—Epoxy Composites

“…The experimental dielectric constant of the structured composite more or less matches the dielectric constant values predicted by Bowen's model for an interparticle distance, ip = 0.20 μm. The interparticle distance found here is clearly smaller than the values reported for structured PZT‐epoxy composites …”

“…For well‐developed “chains”, the topology of such composites approaches that of very expensive composites based on perfectly aligned fibers with a length equal to the electrode distance . Whereas the piezoelectric properties of such “quasi” 1–3 composites will remain below those of “real” 1–3 fibrous composites, the bending and stretching fatigue behavior of the quasi‐1–3 composites is far superior …”

Electrical and mechanical properties of BZT − xBCT lead‐free piezoceramics

“…In another study, Takahashi et al reported the bending strength of 185 MPa for pure BNT, which improved to 215 MPa for Nb‐doped BNT piezoceramics. In addition, the results of our study are higher than the values that were reported for pure PZT with flexural strength and modulus of 85 and 1.5 MPa, respectively …”

Piezoelectric Properties of a Pioneering 3‐1 Type PZT/Epoxy Composites Based on Freeze‐Casting Processing

“…Taking the products of the Morgan Technical Ceramics Company as an example, the standard 1‐3 piezocomposite materials (material type pcm1‐45) with 45% volume fraction of PZT have low ε r of 565, acoustic impedance of 15, and density of 4.1 g/cm 3 . Furthermore, the 3‐1 type PZT/epoxy piezoelectric composites have rarely been reported because PZT ceramics are hard and brittle resulting in that its structure is difficult to arbitrarily design . While, during the last few years, freeze‐casting process, the templating of porous structures by the solidification of a solvent, has been an effective and simple way to form straight‐through pores in ceramics .…”