Manufacturing technology of piezoelectric ceramics(piezoelectric ceramic sphere)

The process flow chart is as follows: batching - mixed grinding - pre sintering - secondary grinding - granulation - forming - plastic discharge - sintering into porcelain - shape processing - electrode - high voltage polarization - aging test.

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

2、 Mixing and grinding: the purpose is to mix and grind all kinds of raw materials to prepare conditions for complete solid-state reaction in pre combustion Dry grinding or wet grinding is generally adopted. Dry grinding can be adopted for small batch, and stirring ball milling or air flow crushing can be adopted for large batch, with high efficiency.

3、 Presintering: the purpose is to synthesize piezoelectric ceramics by solid state reaction of raw materials at high temperature This process is very important. It will directly affect the sintering conditions and the performance of the final product.

4、 Secondary fine grinding: the purpose is to finely vibrate, mix and grind the pre burned piezoelectric ceramic powder, so as to lay a good foundation for uniform performance of porcelain.

5、 Granulation: the purpose is to make the powder form high-density particles with good fluidity. The method can be carried out manually, but the efficiency is low. The efficient method is spray granulation. This process requires the addition of adhesive.

6、 Forming: the purpose is to press the granulated material into the required preform size blank.

7、 Plastic discharge: the purpose is to remove the adhesive added during granulation from the blank.

8、 Sintering into porcelain: the blank is sealed and sintered into porcelain at high temperature. This link is very important.

9、 Shape processing: grind the burned products to the required finished product size.

10、 Electrode to be: a conductive electrode is arranged on the required ceramic surface. The general methods include silver layer infiltration, chemical deposition and vacuum coating.

11、 High voltage polarization: directional arrangement of electrical domains in ceramics, so that ceramics have piezoelectric properties.

12、 Aging test: after the ceramic performance is stable, check various indexes to see whether it meets the expected performance requirements.

The manufacturing feature of piezo ultrasonic atomizer is to polarize ferroelectric ceramics under DC electric field to make them have piezoelectric effect. Generally, the polarization electric field is 3 ~ 5kV / mm, the temperature is 100 ~ 150 ° C and the time is 5 ~ 20min. These three factors are the main factors affecting the polarization effect. The electromechanical coupling coefficient of piezoelectric ceramics with good performance, such as lead zirconate titanate ceramics, can be as high as 0.313 ~ 0.694.