Cavitation erosion
Material loss caused by vapour bubbles forming in a low-pressure region of a liquid and collapsing against a surface. The damage is mechanical fatigue from repeated implosions, not chemical attack — which is why a harder coating rarely solves it.
Cavitation is a hydraulic condition that happens to leave marks on metal. The pitting is the symptom; the cause is a pressure field that drops below the vapour pressure of the liquid, and it stays there until the hydraulics change.
ASTM G32 ranks materials for cavitation resistance under a vibratory apparatus, which is useful for choosing a repair material. It does not make the cavitation stop, and a component repaired without addressing the suction condition erodes again on the same schedule.
Sources and references
- StandardASTM G32-16(2021) — Standard Test Method for Cavitation Erosion Using Vibratory ApparatusASTM International · accessed August 29, 2026
Where this is covered in depth
- Cavitation damage: a hydraulic problem, not a material oneHow to tell cavitation from abrasion, why a harder impeller delays the failure without fixing it, and what actually stops the damage.
- Slurry wear: reading the mechanism before choosing a materialSliding abrasion, impact and erosion-corrosion call for different answers. Identifying which one dominates is what makes a material choice defensible.