Ultrasonic transducer is a device in ultrasonic processing equipment that converts ultrasonic energy into ultrasonic energy. There are two types of ultrasonic transducers that are widely used today:
1. Magnetostrictive transducer:
Depending on the type of material, magnetostrictive transducers can be divided into two categories: one is metallic materials with magnetostrictive properties (such as nickel, iron-cobalt alloys, aluminum-iron alloys, etc.). It has the characteristics of high mechanical strength, high transmission power, stable performance, medium electroacoustic efficiency, and the operating frequency range is generally below 50 kHz. There are two configurations: window type and ring transducer. The other is made by pressing and sintering with ferrite powder, which is characterized by easy molding, high material resistance, high electroacoustic conversion efficiency, and a working frequency of up to 100 kHz, but the mechanical strength is lower than the former, and the transmitting power is low.
Magnetostrictive transducers also feature a high Curie point, low supply voltage, and easy cooling.
2. Piezoelectric transducer:
Depending on the type of material, piezoelectric transducers can also be divided into two categories: one is a single crystal material with piezoelectric properties (such as quartz crystals) that is cut and ground in a certain direction. It is characterized by high transmission power and high electroacoustic efficiency, and is suitable for high frequency bands (up to several gigahertz). However, due to the high impedance, high supply voltage, it is inconvenient to use; The other is a piezoelectric ceramic formed by the pressing, sintering and polarization of powder materials. It has the characteristics of simple molding, high electroacoustic efficiency, low impedance, low power supply voltage, etc., and is also suitable for high-frequency operation. In addition, a large number of sandwich structures are currently used in the low frequency range (from a few kHz to tens of kHz). Piezoelectric ceramic transducers adopt different polarization and combination methods, which can easily realize different vibration modes to meet the needs of different ultrasonic machining. Its disadvantage is that the tensile strength is low, but due to the abundance of materials and low cost, the application gradually increases.