piezoelectric sensor operating principle

                                     piezoelectric sensor operating principle

  The main methods for the preparation of piezoelectric ceramics include sol-gel method, hydrothermal method, molten salt method, piezo electric disc thick film technology, piezo ceramic has grain orientation technology, and discharge plasma sintering technology. However, the obtained powder cannot be applied to the monitoring of complicated parts due to various disadvantages, and the prepared film is too thin to be widely use for ultrasonic welding transducer. The coating of piezo disc element is thicker than the film and is better able to perform on-line monitoring of the complex part surface, exhibiting better performance than the sintered piezoceramic layer.

  Plasma spray can produce millimeter thick coatings on different substrates. Piezoelectric ceramic plasma spraying is a method in which a piezoelectric ceramic powder is fed into a plasma jet and heated, accelerated, and piezo cylinder transducer is sprayed onto a substrate to form a coating. Because of the high flame center temperature of the plasma spray, it can melt many refractory materials. therefore particularly suitable for the preparation of piezo ceramic coatings.The basic research on piezo-electricity spraying technology began at the end of the 20th century. It is considered that the common defects of piezoelectric ceramic coatings, such as high porosity and piezo ceramic sphere components, can be solved by optimizing the process parameters.

  Through the optimization and improvement of the original process, the PZT piezo ceramics was successfully prepared by plasma spraying technology and its piezoelectric performance was improved. The high-performance ceramic PZT coating prepared by plasma spraying has attracted a great deal of scholars' interest both at home and abroad, and has conducted a large number of in-depth studies for ultrasonic cleaning  transducer. The BaTiO3 and (Ba,Sr) TiO3 coatings prepared by flame spraying have good mechanical and piezoelectric properties; the BaTiO3 coatings prepared by plasma spraying technology are incompletely crystalline tetragonal phase coatings with a lamellar microstructure. Although it has cracks or pores, it still has good piezoelectricity.