Effect of Polarization Mode on Piezoelectric Properties by Different Sections

 Effect of Polarization Mode on Piezoelectric Properties by Different Sections

The polarization characteristic of the piezoelectric ceramic ring used in the ultrasonic motor is an important factor that is affecting the output performance of the ultrasonic motor. Polarization is a key step in obtaining the piezoelectric properties of piezoelectric ceramics, and the polarization process of P4 material piezo rings has many ways. The polarization method of piezoelectric ceramics is used for traveling-wave.ultrasonic motors is commonly used at home and abroad. The method of secondary polarization is used to perform positive and negative polarization after reasonably partitioning according to the vibration modes that are simulated and analyzed. When the polarization of piezoelectric ring vibration sensor is performed under a strong electric field of several thousand volts, a large shear stress will be generated at the division boundary during the polarization, and the shear resistance of the piezoelectric ceramic is generally low, and the positive and negative polarization will be caused by the fragmentation. 

The high rejection rate of piezoelectric ring transducer has led to the need to reduce the polarization voltage, which not only makes the polarization effect insufficient, but also does not fully exert the piezoelectric characteristics of the material. Secondly, due to polarization, it is not only cumbersome to operate, but also has large differences in performance between partitions, and the uniformity is low. In addition, the standing wave amplitude is excited by the two groups of piezoelectric vibrators during the vibration process is unbalanced, PZT material piezoceramic ring is resulting in partitions and motors. The contacting plane generates additional fluctuations in the axial direction of the motor,which is causing the motor to run unstably and reducing the output efficiency.In order to solve the above problems, this section proposes the use of a simultaneous one-way polarization process to improve the in homogeneity of polarization regions left by previous secondary polarization processes, and not only to avoid deterioration of the material due to secondary polarization. , And improving the performance uniformity of the piezoelectric ceramic material in each subarea, while is shortening for polarization time, the operation is simple, and also play a key role in improving the output performance of the ultrasonic motor. 

PZN-PZT piezoceramic rings knock sensor are as for the study. First, the piezo ceramic is partitioned by wire mesh silver plating, and then the positive electrode of the high voltage output is connected to the positive polarization zone of the piezoelectric ceramic, and the negative electrode of the high voltage output is connected to the negative polarization zone of the piezoelectric ceramic. After the polarization device is energized, the piezo transducer datasheets are simultaneously polarized in the same direction. Using the same polarization conditions is polarized electric field of 3.5 kWmm, polarization time of 15 min, and polarization temperature of 140°C, the polarized piezoelectric ceramic sections were measured.