The ultrasonic cavitation threshold is closely related to the frequency of ultrasonic waves. The higher the frequency, the higher the cavitation valve. In other words, the lower the frequency of the ultrasonic cleaning machine, the easier it is for cavitation to occur, and the compression and thinning effect of the liquid at low frequency has a longer time interval, allowing the bubbles to grow to a larger size before collapsing, increasing the height of the air. chemical strength, which is beneficial to cleaning effect.
Therefore, low-frequency ultrasonic cleaning is suitable for the surface of large parts or occasions where there is a high degree of bonding between dirt and the surface of the cleaning parts. However, it is easy to corrode the surface of the cleaning parts, so it is not suitable for cleaning parts with high surface finish, and the cavitation noise is loud. At a frequency of about 40KHZ, under the same sound intensity, the number of cavitation bubbles generated is more than that at a frequency of 20KHZ, and the penetrating power is stronger. It is suitable for cleaning workpieces with complex surface shapes or blind holes. The cavitation noise is small, but the air volume is The chemical strength is low and it is suitable for occasions where the bonding force between cleaning dirt and the surface of the parts to be cleaned is weak. High-frequency ultrasonic cleaning is suitable for fine cleaning of computers and microelectronic components; megahertz ultrasonic cleaning is suitable for cleaning integrated circuit chips, silicon wafers and thin films, and can remove micron and sub-micron dirt without causing any damage to the cleaning parts. Therefore, from the perspective of cleaning effect and economy, the frequency is generally selected in the range of 20-130KHZ. Of course, the correct selection of frequency is crucial, and the selection of a specific and appropriate working frequency requires certain experiments.
