Piezoelectric material is the core of the transducer

This section uses the PZT--5H piezoelectric ceramic material that has been polarized, using the filling method to PZT The material is cut into a piezoelectric ceramic of its polarization direction, and the cross-sectional area is square, and the column width is 36.03 um.The piezoelectric ceramic pillars with a period d of 36.52 um, wherein the slit width is 24.14 um. Finally piezoelectric ceramic phase material volume fraction is referred to as 35.84% of the l-3 type piezoelectric composite. After the acoustic impedance test,The series resonant frequency is the series resonant frequency of 45.968 MHz, and the parallel resonant frequency is 60.253.MHz, the center frequency fc is 53.11 MHz. Finally, the fabricated piezoelectric composite material undergoes a certain process.Shaped to form spherical and cylindrical piezo ceramic element surfaces to focus the sound waves, then add backing material and bonding. Performing the sound field scan on the fabricated transducer, and focus on the ultrasound transducer after scanning the spherical point.The depth of focus transducer is 5 mm, the focus size is 80umx120um; the depth of focus of the cylindrical  focused ultrasound transducer.The value is 5.5mm and the focus size is 100% xZOOum.

When is making transducers, piezoelectric materials transducer is the core of transducers, and traditional piezoelectric materials such as piezoelectric ceramics Porcelain and piezoelectric single crystal have their own advantages and disadvantages in the manufacturing of transducers; piezoelectric single crystal materials have a high electromechanical system.The number can be effectively converted between mechanical energy and electrical energy; however, when is manufacturing a high frequency ultrasonic transducer,However, due to the fragility, brittleness and other defects of the material itself, it is not suitable for making high-frequency focusing transducers; PZT Piezoelectric ceramic disc have good piezoelectric properties and high electromechanical cohesion coefficient, but they have high density and are brittle.It is difficult to process, which has high acoustic impedance, and is difficult to match with air and water. It is also not suitable for making high production.it is frequency focusing transducer. However, with the improvement and development of materials and mechanical manufacturing processes from the 1970s.

In the generation, scientists have formed a piezoelectric material (PZT) and a non-piezoelectric material (polymer) in a certain arrangement to form a pressure that combines the advantages of both piezoelectric and non-piezoelectric materials and suppresses their respective disadvantages of electric composite material,A piezoelectric composite material is having the advantages of both piezoelectric material and non-piezoelectric material and suppressing respective disadvantages is formed.Since piezoelectric composite materials have both the advantages of piezoelectric materials and non-piezoelectric materials and suppress their respective disadvantages, l- 3 type composite materials of piezoelectric disc generator have higher thickness direction electromechanical compared with single-phase piezoelectric composite materials.it is coupling coefficient, low acoustic impedance, low transverse electromechanical cohesion coefficient, low dielectric constant and low mechanical quality factor,1 - 3 type piezoelectric composites are obvious when is making high-frequency ultrasonic transducers. therefore, it is used to make high-frequency focused ultrasound transducers. This article uses high performance l-3 type pressure electro-composite materials through the spherical and cylindrical shaping of piezoelectric composites, successfully developed spherical agglomeration focus and cylindrical focused ultrasound transducers, the main work includes the following aspects: