Cavitationresistant

Cavitationresistant denotes materials, coatings, or components engineered to withstand cavitation, the rapid formation and collapse of vapor bubbles in a liquid near a solid surface. Cavitation occurs when local pressures drop below the liquid’s vapor pressure, commonly in pumps, propellers, valves, and turbines. The collapse of bubbles near a surface generates high-energy jets and shock waves that can erode material, cause pitting, crack growth, and fatigue, reducing efficiency and service life.

Factors influencing cavitation resistance include the material’s hardness and toughness, fatigue strength, and ability to absorb impact without brittle fracture; surface condition and residual stress; and microstructure. To enhance resistance, engineers use materials with favorable combinations of hardness and toughness, apply surface treatments such as nitriding or case hardening, and apply coatings including ceramic, carbide-based, or diamond-like carbon films via thermal spraying or vapor deposition. Protective coatings and removable liners are common on components exposed to severe cavitation, such as pump impellers and marine propellers.

Design approaches also help: optimizing geometry to minimize low-pressure regions, smoothing surfaces, and adding sacrificial liners in high-risk zones.

Assessment typically involves laboratory cavitation erosion tests, measuring mass loss, erosion rate, and incubation period; standards such as ASTM G32 guide laboratory evaluation. Field performance in pumps, propellers, and turbines further informs material and coating choices.

See also: cavitation erosion, wear resistance, tribology.