What is pump cavitation

​When the bubbles generated in the high-speed low-pressure part of the pump flow to the high-pressure part and disappear, impact noise or erosion occurs. Due to this, the surface exposed to the flow may be damaged, and if the cavity is enlarged to a certain extent due to high speed and low pressure, the performance of the pump may be deteriorated or destroyed.

 

More detail can be reffered to below link.

https://en.wikipedia.org/wiki/Cavitation