company news about Processing of Piezoelectric Ceramics

Processing of Piezoelectric Ceramics

When a voltage is applied to a piezoelectric ceramic, mechanical deformation occurs as a function of voltage and frequency. On the other hand, when the piezoelectric ceramic is vibrated, an electric charge is generated. Using this principle, when an electrical signal is applied to a vibrator composed of two piezoelectric ceramics or a piezoelectric ceramic and a metal sheet, the so-called bimorph element, ultrasonic waves will be emitted due to bending vibration. Instead, when ultrasonic vibrations are applied to the bimorph element, an electrical signal is generated. Based on the above effects, piezoelectric ceramics can be used as ultrasonic sensors.

The process flow chart is as follows: batching - mixing and grinding - pre-firing - secondary grinding - granulation - molding - plastic removal - sintering into porcelain - shape processing - electrode - high voltage polarization - aging test.

1. Ingredients: carry out pre-processing of materials, remove impurities and moisture, and then weigh various raw materials according to the proportion of the formula. Note that a small amount of additives should be placed in the middle of the aniseed.

2. Mixing and grinding: The purpose is to mix and grind various raw materials to prepare the conditions for complete solid-phase reaction for pre-sintering. Dry grinding or wet grinding is generally used. Dry grinding can be used for small batches, and stirring ball milling or jet pulverization can be used for large batches, which is more efficient.

3. Pre-burning: The purpose is to conduct solid-phase reaction of each raw material at high temperature to synthesize piezoelectric ceramics. This process is very important. It will directly affect the sintering conditions and the properties of the final product.

4. Secondary fine grinding: The purpose is to finely vibrate and mix the pre-fired piezoelectric ceramic powder, so as to lay a solid foundation for the uniform performance of the ceramic.

5. Granulation: The purpose is to make the powder form high-density granules with good fluidity.

6. Forming: The purpose is to press the pelletized material into the required prefabricated size blank.

7. Plastic removal: The purpose is to remove the binder added during granulation from the blank.

8. Sintering into porcelain: The blank is sealed and sintered into porcelain at high temperature. This part is very important.

9. Shape processing: Grind the fired product to the required finished product size.

10. Electrode: Set conductive electrodes on the required ceramic surface. The general methods are infiltration of silver layer, chemical deposition and vacuum coating.

11. High-voltage polarization: orienting and arranging the internal electrical domains of the ceramics, so that the ceramics have piezoelectric properties.

12. Aging test: After the ceramic performance is stable, test various indicators to see if it meets the expected performance requirements.