Processing, microstructure and electromechanical properties of Pb(Zr, Ti)O3 fibers obtained by thermoplastic co-extrusion (original) (raw)
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Journal of Materials Science, 2011
This article describes the processing and characterisation of lanthanum-doped lead zirconate titanate (PLZT)-based ferroelectric fibres for composite transducer applications. X-ray diffraction of the extruded and sintered fibres indicated some lead loss during sintering; however, the fibres exhibited low porosity (1.54%), high maximum piezoelectric strain (4041 ppm) and relatively low coercive field (0.77 kV/mm). The low coercive field of the lanthanum-doped fibres may be advantageous in terms of facilitating polarization of the fibres in composite architectures.
Fabrication and Characterization of Flexible PZT Fiber and Composite
Ferroelectrics, 2012
ABSTRACT Straight lead zirconate titanate (PZT) fibers with round cross sections were fabricated by extrusion with boric acid and polyvinyl alcohol (PVA) condensation. The sintered fibers showed more tetragonality than the bulk. The dielectric constant of the electrode area perpendicular to the PZT fibers (Z1) was higher than the electrode area parallel to the PZT fibers (R1). Single PZT fiber exhibited higher remanent/saturation polarization and coercive field than the bulk and composite. The piezoelectric constant d33 of the Z1 composite was 300 pC/N for the 75 vol% PZT fibers. The Z1 composite had flexibility and high dielectric and ferroelectric properties, and exhibited promise in conformable and large-area applications.
Characterisation and properties of fine scale PZT fibres
Journal of The European Ceramic Society, 2005
The availability of fine scale lead zirconate titanate (PZT) fibres has enabled advances in actuator and sensor applications, including devices for structural control such as the active fibre composite (AFC). Since PZT fibres form active elements within a functional device, fibre characterisation and optimisation is essential. Several commercially available fibres have been studied, which are representative of two dominant processing routes currently utilised: extrusion and suspension spinning. Fibres have been characterised in terms of morphology (shape factor and diameter variability), microstructure (grain size and porosity), and phase composition (XRD). Certain fibres were found to exhibit properties unsuitable for AFC applications, which suggests that commercial production of fine scale PZT fibres may not yet be fully optimised.
Materials Science and Engineering: B, 1999
The effect of net PbO content (obtained by taking into account the amount of excess PbO added and PbO loss during sintering) on the mechanical and piezoelectric properties of lead zirconate titanate (PZT) ceramics has been studied. The samples were prepared by the solid state route using the morphotropic phase boundary composition Pb(Zr 0.535d Ti 0.465)O 3. Excess PbO was also added to the samples in varying amounts from 0-1.0 wt.%. To vary PbO volatility the samples were sintered with and without a PbO rich atmosphere at 1220°C for 2 h. The resulting Pb content as given by x in Pb 1 + x (Zr 0.535 Ti 0.465)O 3 + x varied from x= −1.7 ×10 − 2 to 1.8 ×10 − 2. The sintered density was found to increase with increasing lead content. The precipitation of the second phase believed to be ZrO 2 is observed for x= −1.7× 10 − 2. The fracture mode changed from intergranular to transgranular with increasing x. The fracture toughness (K IC) and strength are minimum near x =0 and increase with increasing as well as decreasing x. The maximum values of K IC and strength are 1.45 MPa m 1/2 and 90 MPa, respectively, for x =1.8× 10 − 2. The dielectric constant and piezoelectric strain coefficient d 33 increased with x.
Journal of The American Ceramic Society, 2003
Lead zirconate titanate (PZT) fibers are prepared by the sol–gel method using acetic acid and methacrylic acid to control the pH of the PZT precursor sol. The chemical evolution of the precursors, the thermal and crystallization behavior of the PZT gel fibers, and the microstructure of the samples with and without acid addition are analyzed and compared. It is observed that the properties of the fibers are improved when acids are used; particularly longer PZT ceramic fibers (4–5 cm) are obtained after heat treatment and a single perovskite phase is obtained at 550°C when using methacrylic acid. The mechanisms of the acid effect on the strengthening and crystallization of PZT fibers are discussed.
Pb(Zr,Ti)O3 Nanofibers Produced by Electrospinning Process
MRS Proceedings, 2008
Lead zirconate titanate (PZT) nanofibers are obtained by electrospinning a sol-gel based solution and polyvinyl pyrrolidone (PVP) polymer, and subsequent sintering of the electrospun precursor fibers. The PVP content of the precursor solution is critical in the formation of the fully fibrous mats. Scanning electron microscope (SEM) is used to examine the morphology of the precursor fibers and annealed PZT nanofibers. The diameters of the precursor PZT/PVP green fibers have increased with the aging of the precursor solution along with an increase in the viscosity. The viscosity of 500 mPa results in successful fibrous mats, yielding green PZT/PVP fibers with a diameter of 400 nm. The fiber mats are then sintered at 700°C. X-ray diffraction (XRD) pattern of the annealed PZT fibers exhibits no preferred orientation and a pure tetragonal perovskite phase. Preparation of piezocomposites by infusion of epoxy into the nanofiber mat facilitates successful handling of the fragile mats and en...
A comparative study of hard/soft PZT-based ceramic composites
Ceramics International, 2016
The objective of present study is an investigation of the role of mixing level (from macro-to microscale) on the dielectric and ferroelectric properties of doped lead zirconium titanate (PZT) composites with soft/hard counterparts. The composites were prepared by two types of doped PZT (soft and hard), which were mixed on a macroscopic (chessboard) and a microscopic level and densified using a classical sintering procedure. A combined scanning electron microscopy, and atomic force microscopy were performed to obtain new insights about microstructure modifications of the investigated ceramic composites. The dielectric properties and high field and ferroelectric properties demonstrated that the soft behavior is prevailing when using macro-scale mixing, while the micro-scale mixing favors the hard behavior. Therefore, the dominant (soft or hard) behavior can be modified by using different scale mixing methods, providing a possible method of controlling the functional characteristics of PZT-based composites.
Actuators, 2015
B-site substitution in KNN with tantalum results in a higher d33 and dielectric constant. This higher value makes KNNT interesting for lead-free actuator applications. KNNT fibers with diameters of 300 and 500 μm have been extruded and sintered at 1200 °C in a KNNT-enriched atmosphere. Subsequently, the influence of fiber diameter on the microstructure (porosity and grain size) was investigated. The measurements revealed that with decreasing fiber diameter, the porosity increases, whereas the grain size decreases. The influence of these microstructural differences on the piezoelectric properties was evaluated using a novel characterization procedure for single fibers. The larger diameter fibers show an increase in the electromechanical properties measured, i.e., d33, tanδ, Pr, Ec and the free longitudinal fiber displacement, when compared to smaller diameter fibers. The lower alkali losses result in a larger grain size, a higher density during sintering and lead to higher electromechanical properties.
Manufacture and characterization of high activity piezoelectric fibres
Smart Materials & Structures, 2006
Piezoelectric fibres are finding increasing application in a variety of piezoelectric composites, including active fibre composites (AFCs). This paper describes the manufacture and characterization of lead zirconate titanate (PZT) fibres manufactured by viscous plastic processing (VPP). The manufacturing method will be described along with a systematic characterization of the macrostructure, microstructure, phase composition and low and high field piezoelectric properties. A comparison with other available PZT fibres will be made, which demonstrates that the VPP PZT fibres display high piezoelectric coefficients.
Structure and the Electrical Properties of Pb(Zr,Ti)O3 - Zirconia Composites
Journal of the American Ceramic Society, 2012
In this work, the effect of introducing tetragonal yttria-stabilized zirconia (TZ) particles in soft [Pb 0.98 Ba 0.01 ][(Zr 0.53 Ti 0.47 ) 0.98 Nb 0.02 ]O 3 (PZT) was investigated. Both microstructure and electrical properties of the PZT-xTZ (x = 0, 2, 5, 10, 20 vol%) composites were studied and correlated. The addition of zirconia hinders the matrix grain growth, resulting in smaller grains. According to X-ray diffraction analysis, zirconia containing composites have a higher rhombohedral-totetragonal phase ratio, in addition to lower dielectric and piezoelectric properties, in comparison to pure PZT. Electrical properties, in terms of strain-and polarization-electric field hysteresis curves, are presented and correlated with the observed phase compositions and microstructures. The extrinsic contribution to the piezoelectric properties in PZT and PZT-xTZ was studied by measuring the frequency and the stress field amplitude dependences of the piezoelectric d 33 coefficient.