Amount Of PZT Research Articles

Effect of PZT doping amount on microstructure and properties of Fe-based memory alloy composite coating by laser cladding

ABSTRACT To enhance the hardness and wear resistance of 304 stainless steel, Fe-based memory alloy/PZT piezoelectric ceramic (SMA/PZT) composite coatings with different PZT doping amounts (0.5–2 wt.%) were fabricated on 304 stainless steel by laser cladding. Coatings show good metallurgical bonding with the substrate. The microstructure, phase composition, microhardness, wear and corrosion resistance of the composite coating were investigated by scanning electron microscopy, X-ray diffractometer, microhardness tester, friction and wear tester and electrochemical workstation respectively. The results show that the microhardness, wear resistance and corrosion resistance of the composite coating are improved compared to the SMA coating. When the PZT doping amount is 1 wt.%, the SMA/PZT composite coating has the highest microhardness, and its wear and corrosion resistance are optimal compared to other coatings. It proved that 1 wt.% was optimal doping amount of PZT in the composite coating.

Dielectric properties of PFN–PZT composites: From relaxor to normal ferroelectric behavior

Lead iron niobate (PFN) has been reported as a high dielectric ceramic. However, the fabrication of PFN to obtain high purity needs careful preparation and complex techniques. In this study, lead zirconate titanate (PZT) was added to PFN to produce (1-x)PFN–xPZT composites where x = 0, 0.1, 0.2, 0.3, 0.4 and 0.5. The X-ray diffraction (XRD) patterns confirmed that all ceramics had perovskite structure with Pb2FeNbO6 as a second phase when x = 0 and 0.1. Pure PFN could be obtained in the form of PFN–PZT composites with PZT when x = 0.2–0.5. Dielectric behavior of PFN showed relaxor ferroelectric behavior as broad dielectric peak could be observed. The temperature at the maximum dielectric constant increased when PZT was added to PFN ceramics. The change of the degree of diffuseness, the variation of Curie-Weiss behavior and the broadness of dielectric peaks confirmed that the dielectric behavior was less relaxor and more normal ferroelectric when the amount of PZT was increased. Electrical conductivity of PFN–PZT composites was also discussed to explain the change of ferroelectric behavior in relation to the activation energy required for charge hopping process.

An Active Functionally Graded Piezocomposite Plate Subjected to a Stochastic Pressure

Abstract In the paper the analysis of random vibration of an actively damped laminated plate with functionally graded piezoelectric actuator layers is presented. The simply supported plate is subjected to stochastic loading represented by a uniformly distributed pressure. The random input is assumed as a Gaussian sta- tionary and ergodic process. The actuators are regarded as a multi-layer structure arranged of piezofiber composite sub-layers. The sub-layers differ each other with amount of PZT (lead-zirconate-titanate) fibers and are stacked to achieve a desired change of the PZT volume fraction through the actuator thickness. The gradation scheme of constituents and material properties are estimated by parabolic and power functions. Numerical simulations are performed to recognize the influence of the applied random excita- tions and the actuator properties gradations on the characteristics of the stochastic field of active plate deflection i.e. power spectral density, autocorrelation function and variance

Effect of Lead Titanate-Zirconate Additions into Barium Titanate Ceramics on the Dielectric and Piezoelectric Properties of Mixed Compounds

Powders of barium titanate (BT) and lead zirconate-titanate (PZT) were mixed together to form solid solutions in the ceramic system (1 − x)BT · xPZT, where 0 ≤ x ≤ 1. The mixed compounds were synthesized by sintering pressed samples of the mixed powders at high temperatures between 1100–1400°C, for 3 hours. Dielectric and piezoelectric properties of the sintered samples were investigated at room temperature. X-ray diffractograms showed that monophase ceramics with perovskite structure were formed along the whole compositional range. The dielectric permittivity ϵ r increased with increasing amount of PZT, reaching a maximum value of about 6900 for composition with x = 0.6, and then suddenly decreases up to lower values of less than 2000. The piezoelectric properties (electromechanical coupling coefficient k p , voltage and charge constants g and d respectively) behave as follows: at first there is a slight decrease of their values for all compositions with x ≤ 0.6 and then suddenly, and rather constantly, their values increase by more than 100% for compositions with x ≥ 0.6. Such a behavior could possible be explained in terms of the structural changes brought about by the incorporation of PZT phase into BT one. The mechanical mixture of BT and PZT particles of similar dimensions gives rise to both new compositions as well as to distinct particles of BT or PZT of different dimensions under the influence of temperature, whose properties may differ from the initial ones so that their properties can be either the result of a size effect or the compositional one, but most probably the combination of both.