Ultrasonic transducer is an important part of ultrasonic cleaning machine. At present, there are two kinds of ultrasonic transducers, one is magnetic ultrasonic transducer, which is made of nickel or nickel-based alloy; A piezoelectric ultrasonic transducer is made of lead zirconate titanate or other porcelain. When the piezoelectric material is put into the electric field with the working voltage changing, it will produce deformation, in other words, the piezoelectric effect. Relatively speaking, magnetic ultrasonic transducers are made of raw materials that can be deformed in a changing magnetic field.

No matter which type of ultrasonic transducer is used, the compressive strength of cavitation effect is the basic factor. Like other sound wave frequencies, ultrasonic wave is a series of working pressure points, namely a kind of shrinking and expanding wave (the following illustration). If the sound is strong enough, the liquid will open at the wave expansion stage and then cause bubbles; However, in the shrinking phase of the wave, bubbles burst or implode in the liquid, causing a very reasonable impact, which is very suitable for cleaning. The whole process is called cavitation.

Theoretically, the broken cavitation bubble will cause the working pressure to exceed 10000 psi and 20000 psi ° F (11000 ° C) high temperature. At the moment of its breaking, the vibration wave will rapidly radiate out of the source. Independent cavitation bubbles release little kinetic energy, but millions of cavitation bubbles break every second. The total effect will be very obvious. The waste on the surface of the product workpiece will fall off due to strong impact force, which is the characteristic of all ultrasonic cleaning.

If the kinetic energy of ultrasonic is large enough, corrosion will be caused by various parts of the cleaning solution, so ultrasonic can reasonably clean tiny gaps and holes. Cavitation erosion also promotes chemical reaction and accelerates the dissolution of surface facial mask.

It is well known that only when the liquid pressure in a certain area is lower than the gas pressure in the bubble, will cavitation occur in that area. Therefore, this standard can only be selected when the ultrasonic amplitude caused by the ultrasonic transducer is large enough. The minimum output power required for cavitation is called cavitation zero point. Different liquids have different cavitation zero points, so ultrasonic kinetic energy must exceed the zero point to achieve the actual effect of cleaning. In other words, only the kinetic energy exceeds the zero point can cause cavitation bubbles, which is convenient for ultrasonic cleaning.