4.5 Cavitation Damage Summary

Characteristics
Cavitation erosion gives a fine scale roughened texture to the damaged surface. This could possibly be confused with wear by fine particles (see Section 2.4: Erosion damage of white metal journal bearing) or even electrical erosion damage (see Section 8: Electrical damage), but can readily be distinguished by closer examination (electrical damage, for example, shows rounded shiny pits from which molten metal has been removed) and the circumstances in which the damage occurred.

Possible Causes
Cavitation damage is associated with high-speed reciprocating machines, or machines in which the bearings are subject to high frequency vibration. Gaseous cavitation should be suspected in machines handling lubricating oils with gas in solution, most particularly refrigeration compressors in which the refrigerant is in contact with the lubricating oil.

Actions
In many cases a modification of the bearing design can prevent bubble formation in a sensitive part of the bearing. Where cavitation is associated with vibration, it is a secondary effect and the cure is to remove the cause of the vibration.

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