New application of piezoelectric ceramic materials

Views: 1 Author: Site Editor Publish Time: 2019-09-29 Origin: Site

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They are each applied to different components. It has a high coupling coefficient and dielectric constant ,small dielectric loss. These characteristics of PZT material piezoelectric ceramics determine the material is suitable for ultrasonic hydrophone emission transducer and high voltage generating components. It also has a high coupling coefficient and dielectric constant. However, the dielectric loss is relatively large! The quality factor is small, so it is suitable for underwater sound! The receiving component of the ultrasonic transducer has a high quality factor, so it can be used to make a filter by cation holes. Experimental results It shows that the piezoelectric performance is best when the sintering temperature of +, - is effectively reduced, and the resonance frequency is PKQ, which is suitable for piezoelectric sprayers and ultrasonic cleaning transducers. On the basis of +,-, people have developed multi-system piezoelectric ceramics such as ternary system and quaternary system based on +, -. The piezoelectric properties of the piezoelectric ceramics can be adjusted in a wider range, and a piezoelectric ceramic system with excellent performance is obtained, which satisfies the requirements of piezoelectric devices in different fields. Piezoelectric ceramics are widely used in electric field driven electromechanical devices to generate resonance. However, experiments have shown that at low power resonances, piezoelectric ceramics remain unchanged even after prolonged vibration. However, under high power drive, the stability of the piezo ceramics is degraded! Other properties are also degraded. People have discovered through experiments that the reason for this phenomenon is that the temperature of the ceramic surface will increase significantly when oscillating under high frequency driving. Thereby destroying the normal process of ceramic re-aging, resulting in performance degradation. This makes research and development of high-power piezoelectric materials imperative. At present, research in this area is based on +, - and has been successfully applied to high-power transducers. Another example is the development of piezoelectric ceramics that can produce output power in piezoelectric transformers. For multilayer chip devices, we hope that PZT4D material piezoelectric elements have high relative dielectric constant and low dielectric loss at low temperature sintering.

Lead-free piezoelectric ceramics, although lead-based piezoelectric ceramics dominate the application in the piezoelectric field. However, the base piezoelectric ceramic is a material that is harmful to the human body and the environment. Among them, toxic is easy to volatilize during processing and sintering, causing harm to human body and environment. Therefore, the search for a piezoelectric ceramic material that is comparable to piezo ceramics and contains no lead has become an urgent need in the field of electronic materials. At present, the research hotspots at home and abroad mainly focus on two categories: bismuth-containing piezo ceramic sensor and lead-free piezoelectric ceramics with perovskite structure. The layered piezoelectric ceramic is composed of two-dimensional perovskite and layers alternately arranged regularly. Its special layered structure determines the following characteristics: low dielectric constant, high curie temperature, high electromechanical coupling coefficient, and obvious anisotropy and high resistivity. Low dielectric breakdown rate and low sintering temperature . These characteristics determine that the piezo ceramic is particularly suitable for high temperature and high frequency applications, thus solving the defect of unstable performance of piezoelectric ceramics under high power resonance. However, tantalum layered piezoelectric ceramics have their own disadvantages: one is that the coercive field is too high, which is not conducive to polarization; the other is low piezoelectric activity and low resistivity. In order to overcome these two defects, the main use is high temperature polarization, because the coercive field decreases with increasing temperature and doping modification. In order to obtain high impedance, the base is doped, and the densities of the results are both theoretical and above resistivity. In addition, the base was also doped, resulting in a JG of up to 01 A66. These properties determine that tantalum piezo ceramics are suitable for high temperature sensors, oscillators, and filters.

The properties of ceramics were investigated using low temperature sintering. The results show that all samples have a theoretical density of AD and no second phase is produced; doping reduces grain size and limits anisotropic growth; In the lead-free piezoelectric ceramics for perovskite structures, It has a large size for lead-free piezoelectric ceramics and is suitable for use as a driver and a high power device. However, the piezo ceramic's low curie temperature, large coercive field and low relative density limit its application requirements. Gradually eliminate the use of lead and heavy metals. At present, the preparation is still very difficult, especially in terms of density. Doping can increase the density of sintering; using nano-powder to produce nano-powder by fine grinding, and preparing relative-density perovskite piezoelectric ceramic by sintering forging, sodium strontium titanate piezoelectric ceramic is also a hot spot in the research of lead-free piezoelectric ceramics. Having a perovskite structure. Similarly, sodium bismuth titanate also has low piezoelectric activity and large coercive field. At present, the coercive field of the modified material of sodium barium titanate is mainly reduced by adding a plurality of perovskite structure dopants; the piezoelectric ceramics are greatly improved, and the material is suitable for manufacturing a piezoelectric filter and piezoelectric resonators, etc. It can be seen from the above that whether lead-containing piezoelectric ceramics or lead-free piezoelectric ceramics are mainly modified by adding various dopants under the current conditions. Therefore, piezoelectric ceramic materials are generally complex ceramic solid solutions. The composition of multi-component materials adds complexity. This will bring great difficulties to the performance testing of materials. In the performance analysis of materials by traditional methods, in order to obtain the influence of a certain condition change on performance, other conditions are often fixed, and a large number of experiments are carried out to analyze the conditions under investigation. The situation becomes more complicated if the effects of several other conditions under a certain condition are to be studied. Using artificial neural networks to establish accurate mathematical models to accurately predict performance. The method is accurate! More importantly, the optimal performance formula can be budgeted, and its practical value is immeasurable.