Research On The Structure And Properties Of The High-power PZT Piezoelectric Ceramics

Piezoelectric ceramis is successfully applied in many areas. Among them, the High-power ceramics and its applications will remain a hot subject to be concerned. To meet the requirements of high-power devices such as piezoelectric motors, piezoelectric transformersand ultrasonic transducers, it is desirable that the piezoelectric ceramics has high piezoelectric constant, high electromechanical coupling factor, high mechanical quality factor, and low insert loss. On the basis of those properties, possibly high power density and mechanical strength, as well as excellent temperature stability, are alsorequired.In this paper, three series of SrCO3,CeO2,Nb2O5 doped Lead Zirconate Titanate piezoelectric ceramics were prepared with conventional mixed solid oxide. The effect of composition and preparation on the Structure and Properties of the Doped PZT Piezoelectric Ceramics were studied;The samples after sintered were poled; the mechanisms of the domain rotation of the sintered samples were investigated, theoretically. The effect of poling on the structures and properties of ceramics were analyzed in nature, which would provide theory support to the further study. The experimental results indicated, when the Zr/Ti ratios were 54/46, in calcining temperature of 900℃and sintering temperature of 1260℃, for PSZT ceramics, the typical parameters were:ε₃₃^T/ε₀=1380, d₃₃=312pC/N, Kp=0.56, Qm=805, tanδ=0.35%, Tc=351℃. For series B, when the amount of CeO₂ is 0.3wt%,the optimized properties was get, the typical parameters were:ε₃₃^T/ε₀ =1620, d₃₃=346pC/N, Kp=0.57, Qm=1000, tanδ=0.32%, Tc=378℃. For series C when the amount of Nb2O5 is 0.05wt%, the optimized properties was get, the typical parameters were:ε₃₃^T/ε₀ =1810, d₃₃=412pC/N, Kp=0.63, Qm=326, tanδ=0.9%, Tc=367℃. Results showed that the amount of tetragonal phases increased and rhombohedral phase decreased with increasing additives. SEM investigation revealed crystalline grain size decrease with increasing CeO₂,Nb₂O₅ content, The proper dopants could not only improve the temperature stability of resonance frequency, but also optimize piezoelectric properties of the system, they can be used as high power piezoelectric material in some area. In the paper, XRD is used to analyze the lattice structure of synthetic powder; SEM is used to observe the surface of the ceramics.