Cavitation on a pump gear. Photo courtesy GEARTECH © 2013.
Definition: Cavitation damage is caused by the formation and collapse of vapor bubbles that occur in the lubricant. The damage consists of deformation and detachment of surface fragments.
Identification: Cavitation creates a pitted surface that gives the appearance that the surface has been sandblasted. SEM shows deep, rough, clean, honeycomb craters.
Discussion: Cavitation damage in the context of a gearbox is most likely to occur in a gear pump.
Prevention: Reduce gearbox speed. Avoid vibration. If damage is occurring in a gear pump, reduce pump inlet backpressure or redesign the pump.